Cover photos courtesy of the Orange County Historical Society and Jim Peterson 
 

SWIM PLAN FOR

LAKE APOPKA, FLORIDA

Issued in compliance with the 

Surface Water Improvement and Management Act 

Chapter 87-97, Laws of Florida, and 

Rule 17-43.035, Florida Administrative Code

Prepared by 

Victoria R. Hoge, Environmental Scientist 

Roxanne Conrow, Supervising Environmental Scientist 

David L. Stites, Ph.D., Supervising Environmental Scientist* 

Michael F. Coveney, Ph.D., Technical Program Manager 

Erich R. Marzolf, Ph.D., Supervising Environmental Scientist 

Edgar F. Lowe, Ph.D., Division Director 

Lawrence E. Battoe, Ph.D., Assistant Division Director 

With contributions from 

Walt Godwin, Elizabeth Mace, Rolland Fulton, Pam Bowen, Dawne Wilson,* Brian 

McGurk, Gianfranco Basili, Lois Bush,* Jeff Cole, Nancy Christman, and Janet Lowe* 

*Previously with SJRWMD 

July 2003 

Executive Summary 

St. Johns River Water Management District

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EXECUTIVE SUMMARY

The Surface Water Improvement and Management (SWIM) Act of 1987 identified Lake 

Apopka as a priority water body in need of restoration and preservation. Effective 

management of the Lake Apopka watershed is necessary to reverse the degradation of 

the system. In response to this mandate, the St. Johns River Water Management District 

(SJRWMD) has prepared a comprehensive management plan to restore and preserve 

the lake and its environment. 

Lake Apopka was specifically identified for restoration efforts in 1985 by the Lake 

Apopka Restoration Act (Chapter 85, Laws of Florida). The Lake Apopka Restoration 

Council (LARC), SJRWMD, the Florida Department of Environmental Protection 

(FDEP) (formerly the Florida Department of Environmental Regulation), the Florida 

Fish and Wildlife Conservation Commission (formerly the Florida Game and Fresh 

Water Fish Commission), and Lake and Orange counties identified specific projects to 

be conducted in a scope of work. Projects planned and implemented under this 

mandate were incorporated into the Lake Apopka SWIM Plan. 

SJRWMD has relied upon staff knowledge, agency and governmental reviews, public 

comment, and general goals developed by the LARC for guidance in developing the 

Lake Apopka SWIM Plan. These efforts have resulted in a coordinated, planned 

approach to develop economically feasible and environmentally sound strategies for the 

Lake Apopka restoration effort. Previous versions of the Lake Apopka SWIM Plan were 

published in 1989 and 1993. 

The goals of the plan are to (1) restore the water in Lake Apopka to meet Class III water 

quality standards, (2) restore the functional capabilities of the lake’s natural systems, (3) 

re-establish previous recreational and aesthetic values, and (4) implement a 

comprehensive basin management plan. 

Seven priority issues were identified for action in the Lake Apopka restoration effort: 

• Agricultural discharges 

• Lack of fish and wildlife habitat 

• Poor water quality and flocculent sediments 

• Degradation of downstream lakes 

• Low recreational and aesthetic values 

• Nonpoint source pollution 

• Future basin development 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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In the 18 years since the Lake Apopka Restoration Act, SJRWMD has implemented a 

comprehensive array of SWIM projects to address each of these issues. Through years of 

scientific study (diagnostic and feasibility programs), an implementation plan with six 

programs (restoration, planning, land acquisition, regulatory, technical support, and 

public information) and 16 projects was developed. Implementation has four main 

components: 

• Reduce phosphorus (P) loading from external sources, primarily agricultural 

operations, through regulation and land acquisition. 

• Remove P and flocculent sediments from the lake to accelerate recovery of the lake 

through wetland filtration (marsh flow-way) and removal of gizzard shad. 

• Improve food-web structure to improve water quality and benefit production of game 

fish by removal of gizzard shad. 

• Restore lake habitat through littoral zone planting and increased fluctuation in lake 

levels. 

REDUCTION IN NUTRIENT LOADING

The first and foremost step towards the restoration of Lake Apopka is to reduce 

external nutrient loading, focusing primarily on P reductions. Regulatory, land 

acquisition, and restoration activities have been initiated that decrease external 

phosphorus loading to Lake Apopka. 

A major regulatory action in support of the Lake Apopka restoration was to restrict 

external nutrient loading from muck farms on the northern shore of the lake. In June 

1988, SJRWMD and A. Duda and Sons, Inc. (Duda), entered into a consent order 

designed to reduce discharges and help protect water quality according to a fixed time 

schedule through a major restructuring of the surface water control system on Lake Jem 

Farm. 

In May 1989, SJRWMD and the Zellwood Drainage and Water Control District 

(ZDWCD) signed a similar consent order, although an administrative challenge delayed 

implementation of those consent order conditions until 1991. 

The 1996 Lake Apopka legislation 

• Set a phosphorus criterion for the lake of 55 parts per billion “in the event the district 

does not adopt a rule...by January 1997” 

• Gave SJRWMD the legal authority to set a phosphorus discharge limitation 
Executive Summary 

St. Johns River Water Management District

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• Determined that it was in the public interest for SJRWMD to pursue buyout of the 

farms as the long-term solution to the problem 

• Provided partial funding toward farm acquisition 

SJRWMD established a phosphorus criterion of 55 parts per billion for Lake Apopka in 

August 1996. The criterion “will be used to establish discharge limitations for all 

regulated activities within the Lake Apopka drainage basin.” 

Phosphorus discharge limitations for Lake Apopka were approved by the Governing 

Board in December 2002. The rule amendments, which involve Chapters 40C-4, 40C-41, 

40C-42, and 40C-44, F.A.C., and related Applicant’s Handbooks, became effective 

March 7, 2003. 

With funding available from federal and state sources, a total of 13,846 acres (ac) east of 

the Apopka-Beauclair Canal was purchased by the end of 2000. Earlier, all muck farm 

areas (5,833 ac) west of the Apopka-Beauclair Canal were purchased for the Marsh 

Flow-Way Project, a restoration project using marshes to remove particulate 

phosphorus from lake water. 

REMOVE P AND FLOCCULENT SEDIMENTS

Recirculation of lake water through the marsh flow-way, a 21 km2 constructed 

treatment wetland located west of the Apopka-Beauclair Canal, will lead to the removal 

of particle-bound phosphorus. The Marsh Flow-Way Project included design, 

construction, and operation of a 530-ac, demonstration-scale wetland filter. This pilot 

project provided necessary experience and data for the design and construction of the 

3,400-ac, full-scale flow-way. Construction of Phase I (650 ac) of the project was 

completed in 2001. Phase I will start operation when the currently record low lake levels 

increase sufficiently and when consultations with federal agencies are completed. The 

full project is expected to remove 30 metric tons of phosphorus annually from Lake 

Apopka. 

IMPROVE FOOD-WEB STRUCTURE

The Trophic Structure Manipulation and Rough-Fish Harvesting projects tested and 

implemented rough fish (gizzard shad) harvest as an economical means of removing 

nutrients from the lake, increasing water clarity, and improving conditions for game 

fish. Lake Denham (a small hypereutrophic lake representative of Lake Apopka) served 

as the site for an initial pilot study. After removal of gizzard shad was followed by an 

improvement in water quality in Lake Denham, various harvesting techniques were 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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tested in Lake Apopka to determine the most cost-effective method. From 1993 through 

2002, the commercial rough-fish harvest funded by SJRWMD in Lake Apopka removed 

3,729,945 kg (8.2 million pounds) of fish. In addition, removal of shad will benefit the 

lake by reducing internal phosphorus loading caused by fish stirring up the bottom 

sediments, by reducing predation of shad on zooplankton which feed on algae, and by 

reducing the phosphorus recycling that results from the shad’s digestive processes. 

RESTORE LAKE HABITAT

The Littoral Zone Restoration Project examined the potential for stabilization of nearshore sediments with inexpensive, moveable breakwaters and planting of desirable 

vegetation for improved habitat. The first barriers were installed in 1991, followed by 

on-going planting of native vegetation beginning in 1992. By 2001, 40 sites had been 

planted around the 40-mile perimeter of the lake. 

In addition to providing valuable habitat, submersed macrophytes will hasten the 

recovery of the lake through several positive feedback mechanisms. 

Planting “events,” with volunteers of all ages participating, have been sponsored in 

cooperation with county and local governments and the Friends of Lake Apopka 

(FOLA) to restore littoral zone areas bordering public parks around the lake. 

RESTORATION BENEFITS TO DATE

Beginning in 1993, consent orders with the farms resulted in modest reductions in 

phosphorus loading. Also, SJRWMD began removing gizzard shad from the lake. The 

combined effects of these efforts became evident in mid-1995, when the total 

phosphorus (TP) concentration began to fluctuate around a 30% lower value. This 

improvement has persisted to date. Chlorophyll, a measure of algal abundance, also 

declined in mid-1995 and has continued its downward trend. Secchi depth, a measure 

of water clarity, increased over the same period of time. Since 1995, native submersed 

aquatic vegetation, especially Vallisneria americana (eelgrass), has reappeared and has 

continued to recolonize Lake Apopka. In fall 2000, 83 patches of eelgrass were found 

with a combined area of more than 6 ac. These improvements are highly significant in 

that they indicate that Lake Apopka can and will recover from decades of pollution 

once the full restoration program has been implemented. 
Executive Summary 

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PESTICIDE RESIDUES IN FORMER AGRICULTURAL AREAS

Since the Legislature determined that it was in the public interest for SJRWMD to begin 

acquisition of the farms on the north shore of Lake Apopka in 1996, approximately 

13,500 ac of farmland have been acquired east of the Apopka-Beauclair Canal by 

SJRWMD and the USDA National Resource and Conservation Service (NRCS). This 

area, the North Shore Restoration Area (NSRA), will ultimately be restored to wetland 

habitat, thereby reducing the nutrient-rich discharges to the lake. 

During the fall of 1998 and winter of 1999, a significant bird mortality event occurred on 

a flooded portion of the NSRA. The U.S. Fish and Wildlife Service (USFWS) has linked 

this mortality to organochlorine pesticide toxicosis. The NSRA currently is being kept 

dry—by pumping excess water due to rainfall—to discourage its use by wetland birds. 

In March 1999, SJRWMD and NRCS, with support from a 13-agency Technical Advisory 

Group, launched a $1.5 million project to investigate the cause of the bird mortality and 

to determine safe levels for pesticide residues in organic soils. All data on soils and 

sediments, birds, and fish were provided to Exponent Inc., a consulting firm based in 

Bellevue, Washington. Their analysis of the data and draft report on the mortality event 

were completed for review in September 2000. A further draft, which incorporated 

comments from academic and agency reviewers, as well as new data from USFWS, was 

received in April 2003. The information provided by this study will be used to help 

guide interim management of the NSRA and other former muck farms targeted for 

restoration. 

A primary uncertainty for evaluating risk from pesticide residues is the rate of 

bioaccumulation of pesticides from soils/sediments through the food chain to fish and 

then to birds. Soils with high organic matter contents, like those on the NSRA have not 

been studied, nor has environmental fate modeling for pesticides been evaluated under 

similar high organic conditions. Therefore, three additional phases of study were 

necessary: (1) laboratory microcosms, (2) field-scale mesocosms, and (3) bird feeding 

studies. SJRWMD initiated these studies during the spring of 2001. 

In addition to the above studies, SJRWMD started cleanup during 2002 of a small, 

highly contaminated area. This site was discovered during the intensive soil sampling 

conducted in 1999. Also as a result of the intensive sampling and subsequent risk 

analysis, SJRWMD and NRCS have begun reflooding a 700-ac portion of the Duda farm. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

viii 

PROJECT DESCRIPTIONS

Diagnostic projects further our understanding of the functioning of the lake and the 

causes of its degradation. Feasibility projects are directed toward the investigation and 

testing of potential restoration techniques. Of the 16 diagnostic and feasibility projects 

developed, 13 have been completed or no further action is planned. The scopes of the 

remaining three projects have been expanded and are near completion or are on-going. 

A number of restoration techniques originally proposed for Lake Apopka were found 

upon examination to be either ineffective or too costly. These include large-scale 

dredging and sediment recycling, phosphorus inactivation in the lake sediments, 

microbial decomposition, and ichthyofaunal reconstruction. The decision not to proceed 

with pilot-scale implementation of these techniques freed resources to support 

restoration methods that appear more promising. 

In the Lake Apopka SWIM Plan, goals and specific strategies have been developed to 

address the seven priority issues. A total of eight programs implement the strategies of 

the plan. The programs are organized into 32 projects, some of which have been 

completed. The programs and projects included in the Lake Apopka SWIM Plan are 

outlined below. 

A. Diagnostic Program 

 1. External Nutrient Budget—Quantified the exchange of water and nutrients 

between Lake Apopka and its watershed. COMPLETED 

 2. Internal Nutrient Budget—Mapped the type, depth, and chemical characteristics of 

lake sediments. Quantified nutrients returning from the sediments to the water. 

Surveyed the levels and potential toxic effects of substances in the sediments. 

Studied accumulation rates of nutrients in sediments and changes in these rates 

over the past 100 years. COMPLETED 

 3. Mathematical Modeling—Used data collected in the diagnostic and feasibility 

programs to project the effects of selected restoration techniques. COMPLETED 

 4. Phytoplankton-Nutrient Interactions—Provided baseline information on algal 

biomass and productivity. Assessed the consequences of nutrient reduction on 

algal growth. COMPLETED 

 5. Bathymetry—Provided a more recent and complete bathymetric survey of Lake 

Apopka. COMPLETED 
Executive Summary 

St. Johns River Water Management District

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 6. Fishery—Obtain current information on the fishery in Lake Apopka by monitoring 

the game and rough fish populations. Determine changes in the fish community 

resulting from restoration efforts. Evaluate potential effects of existing organic 

toxins on alligator, turtle, and bird populations in Lake Apopka. ONGOING 

 7. Seismic Reflection Profiling—Examined subsurface geology across Lake Apopka 

and assessed the nature of the confining layers between the lake and the Floridan 

aquifer. COMPLETED 

 8. Hydrodynamic Survey—Modeled velocities and directions of water currents in 

selected portions of the lake. Evaluated the mixing dynamics of discharge from the 

marsh flow-way and evaluated possible “short circuiting” of filtered water back to 

the inlet. COMPLETED 

B. Feasibility Program 

 1. Water Hyacinth Demonstration—Tested the ability of water hyacinths to remove 

nutrients from the lake. COMPLETED 

 2. Phosphorus Inactivation/Precipitation—Evaluated the feasibility of using alum as 

a precipitant to trap nutrients in an insoluble matrix. COMPLETED 

 3. Sediment Recycling—Evaluated dredging costs and potential markets for lake 

sediment to make dredging economically feasible. COMPLETED 

 4. Microbial Decomposition—Evaluated ways of stimulating natural microbial 

processes to reduce the bulk of lake sediments and sequester nutrients. 

COMPLETED 

 5. Ichthyofaunal Reconstruction (I, II)—Phase I: Compiled a literature review on 

biomanipulation to determine the applicability to problems in Lake Apopka. Phase 

II: Evaluated the potential for use of exotic fish species to aid in the restoration of 

Lake Apopka by consumption of excess production of algae. COMPLETED 

 6. Trophic Structure Manipulation (I, II, III)—Phase I: Provided baseline data on the 

role of rough fish in plankton and nutrient dynamics. Phase II: Determined the 

effects of gizzard shad removal on lake trophic structure and nutrient recycling. 

Phase III: Tested standard harvesting gear for large-scale rough fish removal in 

Lake Apopka and tested feasibility of using harvested rough fish (primarily 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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gizzard shad) as marketable products to offset the cost of fish removal. 

COMPLETED 

 7. Drawdown and Lake Level Fluctuation—Evaluate the feasibility and ecological 

effects of temporarily lowering the water level in the lake or enhancing water level 

fluctuation. ONGOING 

 8. Socioeconomic Assessment and Methodology—Developed techniques for 

socioeconomic assessment of a lake basin. Assessed the present economic value of 

the recreational and commercial uses of Lake Apopka and predicted future 

economic growth concomitant with water quality improvement. Assessed the 

impact of muck farm buyout on the local economy. COMPLETED 

C. Restoration Program 

 1. Marsh Flow-Way Restoration—Restores muck farmland to marsh land in order to 

filter nutrient-rich water from Lake Apopka. ONGOING; Phase I COMPLETED 

 2. Rough Fish Harvesting—Harvests rough fish species to remove nutrients from 

Lake Apopka and improves water quality through food-web manipulation. 

ONGOING 

 3. Wetland Restoration—Restores acquired properties to wetland habitat and 

examines restoration for effects upon water quality, vegetation, and wildlife. 

ONGOING 

 4. Littoral Zone Restoration—Evaluates the feasibility of isolating and restoring small 

portions of Lake Apopka’s shoreline to vegetated littoral zone and examines the 

potential macrophyte seed source from littoral zone sediments. Establishes an 

on-going planting and monitoring effort. ONGOING 

D. Regulatory Program 

 1. Nonpoint Source Pollution Control—Identifies and controls sources of nonpoint 

pollution affecting Lake Apopka. ONGOING 

 2. Nutrient Loading Limits Adoption—Developed and adopted more stringent 

permitting criteria to protect water resources in the Lake Apopka Basin from future 

development and establishes numerical nutrient loading limits. COMPLETED 
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E. Planning Program 

 1. District Water Management Plan—Provides a means to identify and address water 

resource issues by coordinating with various governmental agencies and other 

entities. ONGOING 

 2. Local Government Comprehensive Plan Review—Reviews and comments on local 

government comprehensive plans. ONGOING 

 3. Land Management Plan for the Lake Apopka Restoration Area—Develops a land 

management plan for the Lake Apopka Restoration Area. ONGOING 

F. Public Information Program 

 1. Public Awareness—Uses multimedia communication techniques to inform and 

educate the public regarding the ongoing and future restoration efforts for Lake 

Apopka. ONGOING 

 2. Local Government Information Project—Makes formal informational SWIM 

Program presentations to Planning Commissions, County Commission Boards, and 

other advisory and governing bodies. ONGOING 

G. Land Acquisition Program 

 1. Marsh Flow-Way Land Acquisition—Acquired farmland west of the ApopkaBeauclair Canal in support of the Marsh Flow-Way Project. COMPLETED 

 2. North Shore Land Acquisition—Acquired muck farms and adjacent conservation 

and preservation lands in the Lake Apopka Basin. COMPLETED (over 99%) 

H. Technical Support Program 

 1. Implementation of Restoration and Management Techniques—Provides overall 

analysis and coordination of diagnostic, feasibility, regulatory, planning, and pilot 

restoration projects. ONGOING 

 2. Restoration Monitoring and Analysis—Implements a restoration and postrestoration monitoring regime. ONGOING 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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 3. Overall Program Management—Manages Lake Apopka SWIM Program. Provides 

annual and quarterly SWIM Plan updates. Provides interagency coordination and 

report preparation as necessary. ONGOING 

The SWIM Plan also contains information on project timetables and budgets. A 

summary of the timetable has been included with the Executive Summary for reference. 

Results of projects mandated and initiated under the 1985 Lake Apopka Restoration Act 

provided a basis for further efforts under SWIM to restore and preserve surface water 

resources in the Lake Apopka Basin. Continued implementation of this SWIM Plan will 

result in recovery of Lake Apopka with attendant economic and social benefits to the 

residents of central Florida. Since 1995, several critical and interrelated water quality 

measures have improved by over 30%. In addition, native submersed plants have 

reappeared and persisted in the lake for the first time in decades. These improvements 

demonstrate that Lake Apopka can and will improve in response to ongoing restoration 

efforts. These improvements in Lake Apopka also facilitate the SWIM-based restoration 

efforts in the Ocklawaha River Basin, which receives the improved downstream flow 

from Lake Apopka. 

Eventual restoration of the most severely polluted large lake in Florida should provide 

the impetus and the technical knowledge for restoration of other severely degraded 

water bodies. Thus, the successful restoration of Lake Apopka represents not only a 

major test of the skills of water resource managers and policy makers, but also the 

commitment of Florida residents to reverse the trend of environmental degradation 

throughout the state. 
Figure ES1. Overall timetable for the Lake Apopka SWIM Program 

St. Johns River Water Management District

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Executive Summary
Figure ES1—Continued 

St. Johns River Water Management District

xiv 

SWIM Plan for Lake Apopka 
Contents 

St. Johns River Water Management District

xv 

CONTENTS

Executive Summary ......................................................................................................................... iii 

List of Figures.................................................................................................................................. xix 

List of Tables.................................................................................................................................... xxi 

List of Abbreviations.................................................................................................................... xxiii 

INTRODUCTION...............................................................................................................................1 

 The Surface Water Improvement and Management (SWIM) Act ...................................1 

 SWIM Plan Development ......................................................................................................2 

 Relationship of SWIM Planning to Other Planning and Management Efforts..............3 

OVERVIEW OF THE LAKE APOPKA BASIN.......................................................................11 

 Description of the Water Body System..............................................................................11 

 History....................................................................................................................................11 

 Climate and Hydrology .......................................................................................................15

 Physiography.........................................................................................................................21 

 Water Quality ........................................................................................................................25 

 Sediments ...............................................................................................................................28 

 Biota ........................................................................................................................................28 

 Land Use/Land Cover .........................................................................................................29 

 Recreation and Public Use ...................................................................................................37

 Nutrient Pollution Sources ..................................................................................................38 

 Toxic Pollutants.....................................................................................................................41 

GOVERNMENTAL JURISDICTION .......................................................................................45 

 Federal ....................................................................................................................................45 

 State.........................................................................................................................................47 

 Regional..................................................................................................................................50 

 Local........................................................................................................................................51 

PLANNING: ISSUES, GOALS, STRATEGIES, PROGRAMS, AND PROJECTS...................53 

 District Planning ...................................................................................................................53 

 Lake Apopka SWIM Plan ....................................................................................................54 
SWIM Plan for Lake Apopka 

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PROGRESS OF THE LAKE APOPKA RESTORATION PROGRAM..................................75 

 Overview................................................................................................................................75 

 Reduction in Nutrient Loading...........................................................................................75 

 Removal of Phosphorus and Flocculent Sediments.........................................................83 

 Improve Food-Web Structure .............................................................................................86 

 Improve Lake Habitat ..........................................................................................................86 

 Other Efforts ..........................................................................................................................89 

PROGRAMS AND PROJECTS..................................................................................................95 

 Project Coding .......................................................................................................................95 

 Program and Project Descriptions......................................................................................96 

DETAIL OF PROJECTS............................................................................................................103 

 Project (LA-1-101-D): External Nutrient Budget ............................................................103 

 Project (LA-1-102-D): Internal Nutrient Budget .............................................................108 

 Project (LA-4-103-D): Mathematical Modeling...............................................................111 

 Project (LA-4-104-D): Phytoplankton-Nutrient Interactions ........................................112 

 Project (LA-4-106-D): Bathymetry ....................................................................................114 

 Project (LA-4-107-D): Fishery............................................................................................115 

 Project (LA-1-108-D): Seismic Reflection Profiling ........................................................119 

 Project (LA-4-109-D): Hydrodynamic Survey ................................................................120 

 Project (LA-4-201-F): Water Hyacinth Demonstration ..................................................121 

 Project (LA-4-202-F): Phosphorus Inactivation/Precipitation .....................................123 

 Project (LA-4-204-F): Sediment Recycling .......................................................................123 

 Project (LA-4-205-F): Microbial Decomposition.............................................................124 

 Project (LA-4-206-F): Ichthyofaunal Reconstruction......................................................125 

 Project (LA-4-207-F): Trophic Structure Manipulation .................................................127 

 Project (LA-4-208-F): Drawdown and Lake Level Fluctuation ....................................129 

 Project (LA-4-209-F): Socioeconomic Assessment and Methodology .........................132 

 Project (LA-3-301-M): Marsh Flow-Way Restoration ....................................................133 

 Project (LA-3-302-M): Rough Fish Harvesting ...............................................................141 

 Project (LA-3-303-M): Wetland Restoration....................................................................143 

 Project (LA-2-304-M): Littoral Zone Restoration............................................................156 

 Project (LA-3-402-M): Nonpoint Source Pollution Control ..........................................159 

 Project (LA-3-403-M): Nutrient Loading Limits Adoption...........................................160 

 Project (LA-6-501-M): District Water Management Plan ..............................................162 

 Project (LA-6-502-S): Local Government Comprehensive Plan Review.....................164 

 Project (LA-6-503-M): Land Management Plan for the Lake Apopka 

Restoration Area................................................................................................................165 

 Project (LA-5-602-S): Public Awareness ..........................................................................167 
Contents 

St. Johns River Water Management District

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 Project (LA-5-603-S): Local Government Information Project......................................169 

 Project (LA-3-701-S): Marsh Flow-Way Land Acquisition ...........................................171 

 Project (LA-3-704-S): North Shore Land Acquisition ....................................................172 

 Project (LA-6-802-S): Implementation of Restoration and Management 

Techniques .........................................................................................................................173 

 Project (LA-6-803-S): Restoration Monitoring and Analysis ........................................175 

 Project (LA-6-804-S): Overall Program Management ....................................................177 

SUMMARY OF PROJECT FUNDING ...................................................................................181 

 Introduction .........................................................................................................................181 

 Funding Sources..................................................................................................................181 

LITERATURE CITED ...............................................................................................................187 

Appendix A—Legislation and Rules .....................................................................................197 

Appendix B—Chronology of Lake Apopka..........................................................................303 

Appendix C—Lakes Inventory ...............................................................................................313 

Appendix D—Land Use/Land Cover Categories ...............................................................317 

Appendix E—Permits...............................................................................................................319 

Appendix F—Governmental Units ........................................................................................333 

Appendix G—Bibliography.....................................................................................................339 

Appendix H—Report Summaries ..........................................................................................369 

Appendix I—Consent Orders .................................................................................................527 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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Figures 

St. Johns River Water Management District

xix 

FIGURES

ES1 Overall timetable for the Lake Apopka SWIM Program ............................................xiii 

1 The St. Johns River Water Management District............................................................12 

2 Major water bodies in the Ocklawaha River Basin ........................................................13 

3 Lake Apopka area features................................................................................................14 

4 Conversion of wetlands to agricultural lands on the north shore of Lake Apopka, 

1941, 1947, 1953, and 1985..................................................................................................16 

5 Subbasins and tributaries that potentially contribute stormwater runoff..................18 

6 Lake Apopka regulation schedule and average monthly discharge volume for the 

Apopka-Beauclair Canal, 1959–88 ....................................................................................19 

7 Topographic relief of the Lake Apopka Basin ................................................................22 

8 Soil hydrologic groups of the Lake Apopka Basin ........................................................24 

9 Lake Apopka mean monthly total phosphorus, January 1987–March 2002 ..............26 

10 Lake Apopka mean monthly chlorophyll a, January 1987–March 2002 .....................26 

11 Lake Apopka mean monthly Secchi depth, January 1987–March 2002......................27 

12 Land use/land cover, 1995, Lake Apopka drainage basin ...........................................35 

13 1995 land use/land cover composition............................................................................37 

14 Muck farms in the Lake Apopka Basin, 1988..................................................................39 

15 External phosphorus budget for Lake Apopka, 1989–94..............................................40 

16 Overall Lake Apopka SWIM Plan ....................................................................................56 

17 Agricultural discharges......................................................................................................58 
SWIM Plan for Lake Apopka 

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18 Lack of fish and wildlife habitat .......................................................................................60 

19 Poor water quality and flocculent sediments .................................................................63 

20 Degradation of downstream lakes ...................................................................................66 

21 Low recreational and aesthetic value...............................................................................68 

22 Nonpoint pollution sources...............................................................................................70 

23 Future basin development.................................................................................................72 

24 Land acquisition 2002—Lake Apopka.............................................................................78 

25 Lake Apopka Basin muck farm discharge of total phosphorus, 1989–1996...............80 

26 Lake Apopka Basin muck farm volumetric discharge, 1989–1998 ..............................81 

27 Lake Apopka mean monthly total phosphorus, January 1987–March 2002 ..............81 

28 Lake Apopka mean monthly chlorophyll a, October 1988–March 2002.....................82 

29 Lake Apopka mean monthly Secchi depth, January 1987–March 2002......................82 

30 Lake Apopka Marsh Flow-Way conceptual design.......................................................84 

31 Littoral zone planting locations, May 2002 .....................................................................88 

32 Overall timetables for the Lake Apopka SWIM Program...........................................104 
Tables 

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TABLES

1 Most probable ranges for trophic state variables in pre-impacted and Class III 

states......................................................................................................................................27 

2 Animal species that may occur in the Lake Apopka Basin and that have been 

granted special status by federal or state agencies ........................................................30 

3 Plant species that may occur in the Lake Apopka Basin and that have been 

granted special status by federal or state agencies ........................................................31 

4 Bird species observed at the Lake Apopka restoration site..........................................32 

5 Population by municipality within the Lake Apopka Basin ........................................36 

6 Evaluation and appraisal report schedule, 2002–2010 ................................................163 

7 Estimated capital and operating funding required for Lake Apopka SWIM 

projects, FY 2002–2006......................................................................................................182

8A SJRWMD land acquisition in the Lake Apopka Basin as of December 20, 2002 .....183 

8B Properties under contract as of December 20, 2002 .....................................................184 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

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Abbreviations 

St. Johns River Water Management District

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ABBREVIATIONS

ac acre 

AOR area of responsibility 

ASTM American Society for Testing and Materials 

AWPB Annual Work Plan and Budget 

BMP best management practice 

CBC Christmas bird count 

cm centimeter 

DWMP District Water Management Plan 

EAR environmental assessment report 

ECFRPC East Central Florida Regional Planning Council 

EPA U.S. Environmental Protection Agency 

ERP environmental resource permit 

ESA environmental site assessment 

ET evapotranspiration 

F.A.C. Florida Administrative Code 

FDACS Florida Department of Agriculture and Consumer Services 

FDCA Florida Department of Community Affairs 

FDEP Florida Department of Environmental Protection 

FDER Florida Department of Environmental Regulation 

FDNR Florida Department of Natural Resources 

FDOT Florida Department of Transportation 

FEMA Federal Emergency Management Agency 

FOLA Friends of Lake Apopka 

FS Florida Statutes 

FSA Farm Service Agency 

ft foot 

ft3 cubic foot 

ft3/s cubic feet per second 

FWC Florida Fish and Wildlife Conservation Commission 

GIS geographic information system 

GPS global positioning system 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

xxiv 

ha hectare 

IFAS Institute of Food and Agricultural Science 

in. inch 

kg kilogram 

km kilometer 

LARC Lake Apopka Restoration Council 

m meter 

m3 cubic meter 

m3

/s cubic meters per second 

mgd million gallons per day 

mg/L milligrams per liter 

MSSW management and storage of surface waters 

N nitrogen 

NGVD National Geodetic Vertical Datum 

NOAA National Oceanic and Atmospheric Administration 

NPDES National Pollution Discharge Elimination System 

NRCS National Resource and Conservation Service 

NSRA North Shore Restoration Area 

NWS National Weather Service 

OCP organochlorine pesticide 

P phosphorus 

P2000 Preservation 2000 

PLRG pollutant load reduction goal 

ppb parts per billion 

RPC regional planning council 

SCS Soil Conservation Service 

SJRWMD St. Johns River Water Management District 

SOR Save Our Rivers 

SRPP strategic regional policy plan 

SWIM surface water improvement and management 

TCC Tower Chemical Company 
Abbreviations 

St. Johns River Water Management District

xxv 

TMDL total maximum daily load 

TP total phosphorus 

UF University of Florida 

USDA U.S. Department of Agriculture 

USACE U.S. Army Corps of Engineers 

USFWS U.S. Fish and Wildlife Service 

USGS U.S. Geological Survey 

WRP Wetlands Reserve Program 

yd3

 cubic yard 

ZDWCD Zellwood Drainage and Water Control District 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

xxvi 
Introduction 

St. Johns River Water Management District

1 

INTRODUCTION

This section discusses the various legislative and administrative programs that augment 

the Lake Apopka Surface Water Improvement and Management (SWIM) Plan. The next 

section of this document provides a brief overview of Lake Apopka and its watershed, 

followed by a section outlining the local, regional, state, and federal governments that 

have jurisdiction over Lake Apopka and/or the area within one mile of its banks, as 

required in Chapter 87-97, Laws of Florida (Appendix A). 

Seven priority issues have been identified for Lake Apopka. These issues represent the 

major problems that must be addressed in order to achieve restoration of the lake. The 

Planning section defines these issues and presents the goals, strategies, programs, and 

projects that address each issue. The status and progress of the Lake Apopka 

restoration are discussed in the next section. The Programs and Projects section is 

followed by the Details of Projects section, which contains details of program and 

project organization, describes project identification coding, and provides a brief 

description of the individual projects. 

The Lake Apopka SWIM Plan is designed to be project-oriented. It is at the project level 

where the substance of the plan is implemented. Each project addresses a specific 

activity; active projects are detailed with timelines and itemized budgets in the 

Summary of Project Funding section. 

SWIM programs are not intended to replace existing efforts or responsibilities, but 

rather to integrate efforts by local, regional, state, and federal agencies. Likewise, SWIM 

funds supplement programs and identify areas where monies need to be appropriated 

by other agencies. 

THE SURFACE WATER IMPROVEMENT AND MANAGEMENT ACT

The SWIM Act (Chapter 87-97, Laws of Florida, and Section 373.451, Florida Statutes [FS], 

in Appendix A), was enacted in 1987 by the Florida Legislature to address one of the 

state’s most pressing problems. That body found that the quality of many surface 

waters of the state had been or were in danger of becoming degraded. This degradation 

resulted from point and nonpoint source pollution and destruction of natural systems 

that purify surface waters and provide habitats for plants, fish, and wildlife. It was 

determined that surface water problems can be corrected and prevented through 

programs implemented by the regional water management districts with the 

cooperation of state agencies and local governments. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

2 

The intent of the legislation was to provide aesthetic and recreational pleasure for the 

people of the state; to provide habitat for native plants, fish, and wildlife, including 

endangered and threatened species; to provide safe drinking water to the growing 

population of the state; and to attract visitors and accrue other economic benefits. 

The SWIM legislation specifically designated Lake Apopka as a water body in need of 

restoration. 

Each of the state’s five water management districts, in cooperation with the Florida 

Department of Environmental Protection (FDEP), the Florida Department of 

Agriculture and Consumer Services (FDACS), the Florida Department of Community 

Affairs (FDCA), the Florida Fish and Wildlife Conservation Commission (FWC), and 

local governments, was mandated to prepare a list of prioritized water bodies of 

regional or statewide significance based upon criteria adopted by FDEP rule. In 

compliance with this mandate, the St. Johns River Water Management District 

(SJRWMD) staff prioritized water bodies within SJRWMD in 1988 (SJRWMD 1988). The 

water bodies were reprioritized in 1991 (Adamus 1992). 

The legislation also charged the water management districts, in cooperation with state 

agencies and local governments, to develop and implement SWIM plans for surface 

water improvement and management of water bodies based upon the priority list 

approved by FDEP. The SWIM plans are required to be updated at least every three 

years. These updates provide continued opportunities for input and re-evaluation of the 

plans as the restoration and management programs develop. 

FDEP established a uniform format for SWIM plans with the necessary flexibility to 

accommodate particular circumstances of the individual water bodies. The format 

designates the following six central concerns as the focus of the SWIM Act: 

1. Point and nonpoint source pollution 

2. Destruction of natural systems 

3. Correction and prevention of surface water problems 

4. Research for better management of surface waters and associated natural systems 

5. Public awareness 

6. Improved coordination and management 

SWIM PLAN DEVELOPMENT

Chapter 85-148, Laws of Florida, created the Lake Apopka Restoration Act and 

established the Lake Apopka Restoration Council (LARC) in 1985 (Appendix A). 
Introduction 

St. Johns River Water Management District

3 

SJRWMD, in conjunction with FDEP, FWC, Lake and Orange counties, and the LARC, 

was mandated to determine environmentally sound and economically feasible 

restoration projects for Lake Apopka. As a result of that mandate, a scope of work for 

the restoration of Lake Apopka was developed by the LARC and adopted by the 

SJRWMD Governing Board. In 1986, the Governing Board directed the staff to begin 

restoration efforts for the lake. With the passage of the SWIM Act, SJRWMD 

incorporated projects from the scope of work into the SWIM planning process. 

The SWIM Act specifically designated Lake Apopka, the lower St. Johns River, and the 

Indian River Lagoon as the first SWIM programs in SJRWMD (Adamus 1992). 

The original Lake Apopka SWIM Plan expanded on previous restoration efforts (see the 

Planning section for a detailed description of the planning process), using several steps: 

• Identification of problems and issues 

• Definition of goals 

• Program development 

• Determination of program strategies 

• Project development 

• Definition of project objectives 

• Determination of priorities for action 

The original Lake Apopka SWIM Plan was accepted by the Governing Board in 1989 

and approved by FDEP in the same year. With the development of this plan and the 

primary mission of the LARC complete, the Governor did not re-appoint the members 

of the restoration council for further service. In 1993, an update of the Lake Apopka 

SWIM Plan was completed.

RELATIONSHIP OF SWIM PLANNING TO OTHER PLANNING AND 

MANAGEMENT EFFORTS

District Water Management Plans 

District water management plans (DWMPs), initially prepared by the five water 

management districts in 1994 and updated every five years, provide long-term 

guidance for water management district activities, identify performance measures for 

the districts and district programs, and serve as a source of technical information on 

water resources. The DWMPs are incorporated into the Florida Water Plan, initially 

prepared by FDEP in 1995 and also updated every five years. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

4 

Requirements for the DWMPs are found in the Water Resource Implementation Rule 

(62-40.520, Florida Administrative Code [F.A.C.]) and in Section 373.036, FS. The format of 

the plans is developed jointly by the water management districts and FDEP. Additional 

guidance for preparation of the DWMPs comes from the policies, responsibilities, and 

authority relating to water management districts in various state statutes and rules. 

The overall goal for the DWMPs and activities of all the water management districts is 

stated in the Water Resources element of the State Comprehensive Plan (Chapter 187, 

FS), as follows: 

Florida shall assure the availability of an adequate supply of water for all 

competing uses deemed reasonable and beneficial and shall maintain the 

functions of natural systems and the overall present level of surface and 

ground water quality. Florida shall improve and restore the quality of 

waters not presently meeting water quality standards. 

The state’s goal is realized through individual district goals established for the four 

district areas of responsibility (AORs): water supply, flood protection and floodplain 

management, water quality, and natural systems. 

SJRWMD’s May 2000 DWMP identifies issues, objectives, strategies, and performance 

measures as well as a goal for each AOR, and issues, strategies, and program-specific 

performance measures for major watersheds. Issues were identified using resource 

assessments, information gathered from SJRWMD and other agency staff and various 

data sources, and input received from local government staff, elected officials, and the 

public at workshops conducted as part of the DWMP development process. Strategies 

to address the issues were developed by SJRWMD staff, taking into account input 

received at the DWMP workshops. 

Issues, strategies, and performance measures relating to the Lake Apopka SWIM 

program are included in the chapter on watersheds. SJRWMD’s schedule for 

developing pollutant load reduction goals (PLRGs) for SWIM and other water bodies 

and related strategies are included in the chapter on the water quality AOR. PLRGs for 

Lake Apopka are more fully discussed in the Progress section and in the description for 

Project LA-3-403-M (Nutrient Loading Limits Adoption) in the Detail of Projects 

section. 

Watershed Management Program 

Beginning in July 2000, FDEP began implementing a comprehensive approach to 

protect water quality involving basinwide assessments and the application of a full 
Introduction 

St. Johns River Water Management District

5 

range of regulatory and nonregulatory strategies to reduce pollution through the 

Watershed Management Program. This program is based on a five-phase cycle that 

rotates through Florida’s basins every five years. The five phases include 

• Initial basin assessment 

• Strategic monitoring 

• Data analysis and total maximum daily load (TMDL) development 

• Watershed plan development 

• Watershed plan implementation 

Each cycle will lead to the development of a detailed watershed management plan that 

focuses on protecting healthy water bodies and reducing pollution in impaired surface 

waters, usually by developing a TMDL. The Ocklawaha River Basin, which contains Lake 

Apopka, is included in the first group of basins that is being evaluated. 

TMDLs establish the maximum amount of a pollutant that a water body can assimilate 

without causing exceedances of water quality standards. Implementation of TMDLs 

refers to any combination of regulatory, nonregulatory, or incentive-based actions that 

attain the necessary reduction in pollutant loading. Section 303(d) of the federal Clean 

Water Act requires states to submit lists of surface waters that do not meet applicable 

water quality standards and establish TMDLs for these waters on a prioritized 

schedule. FDEP’s authority for Florida’s TMDL program was established with the 1999 

Florida Watershed Restoration Act. TMDLs may be based on PLRGs. PLRGs are 

defined as estimated numeric reductions in pollutant loadings needed to preserve or 

restore designated uses of receiving bodies of water and maintain water quality 

consistent with applicable state water quality standards. PLRGs are developed by the 

water management districts. 

Local Government Comprehensive Plans 

Each local government is required to have a comprehensive plan to guide its future 

development and growth pursuant to the Local Government Comprehensive Planning 

and Land Development Regulation Act (Chapter 163, FS). The act specifies elements to 

be included and requires that they be internally consistent and that plans be 

economically feasible, sets out procedures for plan adoption and amendments, 

addresses plan implementation, and contains sanction and enforcement provisions. It 

also requires that local government comprehensive plans be consistent with the 

applicable strategic regional policy plan and the state comprehensive plan. Given the 

broad scope of a comprehensive plan and the strong consistency requirements, there 

may be no action a local government can take which has more impact on its constituents 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

6 

and resources, including natural resources, than development. All private and public 

development and all local land development regulations must be consistent with the 

adopted comprehensive plan. Also, although a comprehensive plan can be amended, it 

sets the tone and direction for the municipality or county it covers for at least a 10-year 

period. 

A number of the elements required in local government comprehensive plans provide a 

means to address many water resource issues in the Lake Apopka Basin. These include 

the Future Land Use Element; the Conservation Element; the Sanitary Sewer, Solid Waste, 

Stormwater Management, Potable Water and Natural Groundwater Aquifer Recharge 

Element; the Capital Improvements Element; and the Intergovernmental Coordination 

Element. 

Local governments are also required to perform periodic assessments of their progress 

in implementing their comprehensive plans. These assessments, known as evaluation 

and appraisal reports (EARs), identify any needed actions or corrective measures. The 

next round of due dates for EARs for local governments in the Lake Apopka Basin 

ranges from July 2005 for Orange County to June 2009 for Montverde. The schedule for 

submittal of adopted EAR reports for the years 2002 through 2010 is included in Project 

LA-6-502-S in the Detail of Projects section. 

SJRWMD intergovernmental coordinators work with local governments on land 

development regulations to promote improved implementation of comprehensive plan 

policies to protect water resources. 

Stormwater Planning 

Stormwater issues are addressed at the local, regional, state, and national levels. 

Historically, stormwater concerns centered on how to most expediently transport storm 

water from urban or agricultural areas. More recently, stormwater issues have been 

broadened to include water quality concerns, not just draining the land. 

Stormwater management is most effective from a watershed perspective, with 

coordination among local governments in the watershed or subbasins within the 

watershed. Local government comprehensive plans, required by Chapter 163, FS, 

provide an excellent opportunity for local governments to review their existing 

stormwater management facilities and programs, adopt policies to address existing 

deficiencies and meet future needs, and coordinate with adjacent local governments. 

Stormwater master plans may be tied to local government comprehensive plans. Master 

plans are useful tools for performing inventories and evaluating drainage improvement 

and stormwater treatment needs within individual watersheds. 
Introduction 

St. Johns River Water Management District

7 

Regulatory Programs of Governmental Bodies 

Regulation of water quality is delegated to the states under Section 401 of the federal 

Clean Water Act. The state originally regulated surface water quality through the 

wetland resource management (dredge and fill) and stormwater rules. The water 

management districts administered the management and storage of surface waters 

(MSSW) rule and the stormwater rule. In addition, under a formal operating agreement 

with FDEP, SJRWMD administered a portion of the Wetland Resource Management 

program. Under the 1993 Streamlining Act, the MSSW, Stormwater, and Wetland 

Resource Management regulatory programs were combined to create the 

environmental resource permit (ERP) program. First issued in 1995, the purpose of 

ERPs is to address impacts to wetlands and to ensure that construction takes into 

account flood protection and the protection of waterways from stormwater pollution. 

County and municipal governments have several regulatory means to address 

stormwater issues. The most direct means of stormwater regulation is through a local 

“stormwater management ordinance.” The effectiveness of such an ordinance depends 

on the permitting thresholds, the restrictiveness of the requirements, and the degree of 

inspection and enforcement established by the local government. 

Regional Planning Councils 

Pursuant to changes made to the Florida Regional Planning Council Act in 1993, 

regional planning councils (RPCs) prepared and adopted strategic regional policy plans 

(SRPPs) which contain regional goals and policies addressing natural resources of 

regional significance, affordable housing, economic development, emergency 

preparedness, regional transportation, and any other subjects relating to the particular 

needs and circumstances of a region. The SRPPs also identify and address significant 

regional resources and facilities. They replaced the comprehensive regional policy plans 

previously adopted by the RPCs but still are required to be consistent with the state 

comprehensive plan. The SRPPs provide the basis for regional reviews of local 

government comprehensive plans and plan amendments, developments of regional 

impact/Florida quality developments, and other regional comment functions. 

The Lake Apopka Basin is contained within the East Central Florida Regional Planning 

Council jurisdiction. The east-central Florida SRPP consists of four documents: At This 

Point in Time (physical, economic, and social profile of the region), What the Future Holds

(trends over the next 30 years), Water, Plants and Concrete (resources and facilities of 

regional significance), and Taking the Next Step (goals and policies/planning 

process/regional review functions/use of geographic information systems). Taking the 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

8 

Next Step contains general policies on water-related resources but also anticipates 

additional planning and policy development for sub-areas of the region. General 

planning objectives are being implemented under a coordinated regional planning 

effort, the Lake Apopka Basin Planning Initiative. 

SJRWMD planning staff participated in the RPC processes used to develop the SRPPs 

applicable to counties in SJRWMD. That participation involved serving on technical 

advisory committees, evaluating policies, and providing technical data. Review of the 

east-central Florida SRPP in 2001 did not result in any amendments affecting Lake 

Apopka. 

Land Acquisition Program 

When the water management districts were established in 1972, the Florida Legislature 

provided the districts with the general authority to utilize land acquisition as one of the 

primary tools for carrying out the mission of “flood control, water storage, water 

management, and preservation of wetlands, streams, and lakes” (Section 373.139, FS). 

Subsequently, the Legislature established additional land acquisition programs with 

specific directives for the expenditure of funds. 

The Save Our Rivers (SOR) legislation of 1981 created the Water Management Lands 

Trust Fund for acquiring a fee-simple or other interest in lands necessary for water 

management, water supply, and the conservation and protection of water resources. In 

1986, Section 373.59, FS (Appendix A), was amended to allow for the use of up to 10% 

of the monies from the trust fund for management, maintenance, and capital 

improvements. This allocation was increased to 15% in 1992. In 1995, the statute was 

amended to allow up to a maximum of 25% of the Water Management Lands Trust 

Fund to be used for management purposes. In 1997, the limit on management use was 

removed altogether. 

The Preservation 2000 (P2000) Act passed in 1990 provided additional funding for the 

water management districts for land acquisition, contingent on annual funding 

appropriated by the Legislature over a 10-year period. The program used bond 

proceeds supported by the general revenue portion of the documentary stamp tax. The 

P2000 Act recommended that governmental agencies work together to purchase lands 

jointly with a coordinated goal of protecting ecological systems. A major recipient of 

P2000 funding was the Conservation and Recreation Lands program. Established in 

1979 by the Florida Legislature, the Conservation and Recreation Lands program 

received funding from bond proceeds, severance taxes on phosphate mining, and excise 

taxes on real estate and financial documents. 
Introduction 

St. Johns River Water Management District

9 

The Florida Forever Act (Section 259.105, FS) was passed in 1999 as the successor to the 

P2000 Act. It provides for the issuance of up to $3 billion in bonds over a 10-year period 

to be used for land acquisition, water resource development, stormwater management, 

water body restoration, recreational facility construction, public access improvements, 

invasive plant control, and related projects. The annual appropriation of up to $300 

million is divided among programs administered by FDEP, the Florida Communities 

Trust, the Division of Forestry, FWC, and the five water management districts. Over the 

life of the program, at least 50% of the funds must be spent on land acquisition and the 

balance on capital improvement projects. 

SJRWMD’s Land Acquisition and Management Five Year Plan has been replaced by the 

Florida Forever Work Plan. The Florida Forever Work Plan, which covers a five-year 

period with updates in January of each year, presents projects eligible for funding 

under the Florida Forever Act and reports on project implementation. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

10 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

11 

OVERVIEW OF THE LAKE APOPKA BASIN

DESCRIPTION OF THE WATER BODY SYSTEM

Lake Apopka, the fourth largest lake in Florida, is the headwater lake for the Harris 

Chain of Lakes (Figure 1). The lake is located at latitude 28o 37’ N and longitude 81o 38’ 

W and is within Orange and Lake counties (Figure 2). The nearest major metropolitan 

area is Orlando, located to the southeast about 25 kilometers (km) (15 miles). The water 

surface of the lake is approximately 12,465 hectares (ha) (30,800 acres [ac]) at lake 

surface elevation 20.2 meters (m) (66.5 feet [ft]) National Geodetic Vertical Datum 1929 

(NGVD 29). Average depth at this surface elevation is 1.6 m (5.4 ft). 

The only surface water outflow from Lake Apopka is the Apopka-Beauclair Canal, 

which flows north into Lake Beauclair (Figure 3). Discharge from the canal is controlled 

at the Apopka-Beauclair Lock and Dam, which therefore influences lake stage. 

HISTORY

Historically, Lake Apopka covered approximately 20,235 ha (50,000 ac) and had an 

average depth of 2.4–2.7 m (8–9 ft). The northern third of the lake was a shallow marsh 

system, which afforded habitat for abundant fish and wildlife populations. Prior to its 

decline, the lake provided superb sportfishing of national renown. During periods of 

high water, the lake likely drained to the northwest into Little Lake Harris, through an 

area known as Double Run Swamp. 

Numerous activities in the nineteenth and twentieth centuries have contributed to the 

decline of the lake. Significant human impact affecting Lake Apopka probably began 

with the construction of the Apopka-Beauclair Canal, which altered the hydrology of 

the lake. In order to create a waterway for navigation and agricultural use, dredging of 

the Apopka-Beauclair Canal was originally begun by the Apopka Canal Company in 

1880 (Schiffer 1994). In 1893, the Delta Canal Company successfully completed 32 miles 

of lateral ditches and 12 miles of canal from Lake Apopka through Lakes Beauclair, 

Dora, and Eustis to the Ocklawaha River. This action effectively lowered the water 

surface of Lake Apopka by about 4 ft, leaving approximately 8,100 ha (20,000 ac) of 

predominantly sawgrass land dry enough for farming (Shofner 1982). Crop production 

was mostly unsuccessful due to difficulty in water table management and a series of 

freezes in the mid and late 1890s. By 1910, the canal was filled with vegetation and the 

lake stage was similar to its original state (M.H. Connell and Associates 1954). 
ORANGE

SEMINOLE

Blue

Cypress

Lake

Lake 

Washington

Lake

Winder

Lake

Harney Lake

Jesup

Lake

Monroe

Lake

Woodruff

Lake

George

Crescent

Lake

Lake

Apopka

Lake

Harris

Lake

Weir

Orange

Lake

MARION

FLAGLER

ST JOHNS

BAKER

NASSAU

DUVAL

PUTNAM

ALACHUA

Figure 1. The St. Johns River Water Management District

ATLANTIC

OCEAN

S

T J O

H N S

R VI ER

VOLUSIA LAKE

CLAY

Fernandina

Beach

Jacksonville

Green

Cove

Springs St Augustine

Palatka

Gainesville

Ocala

Bunnell

DeLand

Tavares

Orlando

Sanford

Titusville

POLK

OSCEOLA

OKEECHOBEE

INDIAN RIVER

BREVARD

BRADFORD

Ocklawaha

R vi er

County boundary

SJRWMD boundary

Town

Water body

Daytona Beach

Melbourne

0 20 40

N

Approximate scale in miles

82 00 W 81 00 W 80 00 W

30 00 N

29 00 N

28 00 N


	




	

	







	

	



	





  	



	





		
























   



 
























	 

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Overview of the Lake Apopka Basin 

St. Johns River Water Management District

15 

In 1915, the Zellwood Produce Company continued improving the canal in order to 

plant potatoes. The lake level was again lowered, this time to 63 ft NGVD 29 despite the 

protest of agricultural producers on the southern shore of the lake who feared water 

supply shortages, decreased cold protection, and a threat to navigation. However, a 

destructive blow was struck by a hurricane in 1926, and the entire north shore farm area 

reverted to marshland “under six to eight feet of water” (Shofner 1982). 

Due to improved technology, farming returned during World War II. In 1941, the 

Zellwood Drainage and Water Control District (ZDWCD) was created by a special act 

of the Legislature and charged with facilitating agricultural production activities. In 

1941, the mean elevation of the lake was approximately 67 ft NGVD 29, the same 

elevation as the muck and peat land along the northern shore at that time. These lands 

were inundated when the lake rose above the mean elevation, and during lower lake 

stages, these lands drained into the lake or into the Apopka-Beauclair Canal. Under the 

management of ZDWCD, a levee was constructed on the north shore, effectively 

separating the marshes from the lake and allowing drainage of the farm fields (Shofner 

1982). Aerial photography of the northern end of the lake taken in 1947 shows 

approximately 1,162 ha (2,870 ac) in row crops and an additional 1,974 ha (4,875 ac) 

being prepared for farming (Figure 4). A lake stabilization program was begun in 1952 

(Schiffer 1994), and the Apopka-Beauclair Canal was deepened just two years later. 

Agricultural production peaked within the muck farms during the 1980s, with 7,290 ha 

(18,000 ac) of farmed land. With the final government purchase of the remaining muck 

farms on August 20, 1999, ZDWCD was dissolved in February 2000 by mandate of the 

1999 Florida Legislature. A detailed chronology of Lake Apopka’s degradation is 

provided in Appendix B. 

CLIMATE AND HYDROLOGY

Rainfall 

Due to the subtropical climate of the Lake Apopka area, annual rainfall averages about 

127 centimeters (cm) (50 inches [in.]). Typical seasonal precipitation patterns include a 

dry season from November to May and a wet season from June to September. About 

60% of the total annual rainfall occurs during the four-month summer season as 

convective thunderstorms. Frequency of precipitation during the remainder of the year 

is lower, with measurable amounts occurring on about 25% of the days. Precipitation 

during this period occurs primarily from frontal events and is usually moderate. 

Rainfall is the major source of water to the lake. Rainfall statistics for area monitoring 

stations at Lisbon, Ocala, and Clermont are summarized in Jenab et al. (1986), Rao (1988, 

1991), and Rao et al. (1989, 1990a, and 1990b). 

Overview of the Lake Apopka Basin 

St. Johns River Water Management District

17 

Evapotranspiration 

Evapotranspiration (ET) is the combined water loss due to evaporation and 

transpiration. ET is a major component of the water budget in the basin. Affected by 

wind, temperature, solar radiation, relative humidity, and plant transpiration, the 

average annual potential ET value for the Lake Apopka Basin is approximately 109 cm 

(43 in.) (Fernald and Purdum 1998). 

Drainage Basin 

The area of the Lake Apopka drainage basin, including the surface of the lake, is 

approximately 48,471 ha (119,773 ac). Several subbasins contribute either direct 

stormwater runoff or runoff through small tributaries during rainfall events (Figure 5). 

However, many portions of the drainage basin contribute runoff infrequently. More 

than 60 small lakes are scattered throughout the basin, but they are generally 

landlocked except in periods of extreme runoff events (Appendix C). 

Springs 

The largest spring in the basin, Apopka Spring, also known as Gourd Neck Spring, 

discharges into Gourd Neck, a narrow water body located in the southwest corner of 

the lake. The spring opening is at a depth of approximately 11.2 m (37 ft) (Rao and 

Clapp 1996). Fed by the Floridan aquifer, the spring discharges from a single 

submerged oval-shaped opening 5–6 ft in diameter (LCWA 1985). The average 

discharge rate of Apopka Spring was approximately 0.85 cubic meters per second 

(m3

/s) (29.9 cubic feet per second [ft3/s]) from 1988 through 1998 (range, 0.76–0.99 

m3

/s), depending on the lake stage level (Stites et al. 2001). Based on the Meinzer spring 

discharge scheme, Apopka Spring is classified as a magnitude 2 spring (Rosenau et al. 

1977). McGurk and Presley (2002) projected that by the year 2020, a discharge reduction 

of up to 24% could be realized due to projected increases in groundwater withdrawals if 

alternative water sources are not utilized. This could reduce total discharges to 

downstream water bodies. 

Three other named springs exist in the basin; however, discharge information is not 

available. Holt Lake Spring is located just south of Holt Lake. Bear Spring and Wolf’s 

Head Spring are located just southwest of Clay Island. 

Overview of the Lake Apopka Basin 

St. Johns River Water Management District

19 

Stage Discharge and Regulation 

Lake Apopka has a moderate hydraulic detention time of approximately 2.5 years 

(1959–88 average). Water discharge from the lake occurred via the Apopka-Beauclair 

Canal at a mean annual rate of 6.81 x 107 m3/year (76.4 ft3/s) for the years 1959–99 

(USGS 2002). 

The water control structure in the canal has altered the natural periodic fluctuation of 

the lake stage and discharge. From 1956, when the present structure was installed, 

through July 2002, the lake level has ranged from a low of 19.0 m (62.5 ft) recorded in 

June 2002 to 20.8 m (68.4 ft). 

The seasonal regulation schedule is nearly the opposite of natural seasonal fluctuations 

in water levels; the lake is held at its lowest levels during the summer wet season in 

order to provide flood storage capacity (Figure 6). During periods of low water, a 

minimum discharge is released downstream. This alteration in the natural hydrologic 

cycle may have contributed to declines in aquatic habitat, water quality, and fisheries in 

the basin (SJRWMD 2001b). The U.S. Army Corps of Engineers is initiating an Upper 

66.7

66.8

66.9

67.0

67.1

67.2

67.3

J FMAMJ J ASOND

Month

Lake elevation (ft)

20

30

40

50

60

70

80

90

100

110

120

monthly discharge (cfs)

Lake regulation schedule Average monthly discharge

Figure 6. Lake Apopka regulation schedule and average monthly discharge volume for the 

Apopka-Beauclair Canal, 1959–1988 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

20 

Ocklawaha River Basin Restudy project, which will evaluate operational modifications 

that could be implemented to enhance environmental restoration benefits of the basin. 

During the study phase of this project, alternative lake regulation schedules may be 

tested. 

Aquifer Systems 

Two aquifer systems occur in the study area, the surficial aquifer and the underlying 

artesian Floridan aquifer (Jenab 1986). An aquifer system consists of two or more 

hydraulically connected aquifers (Fernald and Purdum 1998). 

The surficial aquifer is the permeable hydrogeologic unit contiguous with the land 

surface. It holds the water table with water generally under unconfined conditions 

between a depth of 0–60 m (0–200 ft) (Jenab 1986). The water usually contains iron in 

sufficient quantities to give it a pronounced taste. 

The Floridan aquifer is separated from the surficial aquifer throughout most of the 

region by the intermediate confining unit. This unit consists of poorly permeable 

Miocene age Hawthorn Group sediments and, locally, low permeability beds of early 

Pliocene age (Miller 1986; Murray and Halford 1996). Localized beds of permeable sand, 

shell, gravel, or limestone exist within and above the Hawthorn Group sediments. 

These beds can constitute a localized intermediate aquifer when permeable enough to 

produce significant quantities of water to a well, but they are not really extensive 

enough in western Orange County and eastern Lake County to be considered an aquifer 

system. The Hawthorn Group sediments are rich in phosphorus, which may contribute 

to the natural productivity of surface waters in the area. 

The underlying Floridan aquifer is the regional water-yielding hydraulic unit. Water 

from the Floridan aquifer is generally good in quality and suitable for most domestic, 

small irrigation, and light industrial applications. The depth to the top of the Floridan 

aquifer varies throughout the basin and ranges from approximately 25 to 90 m 

(80–300 ft). Wells in the Floridan aquifer are usually cased from ground level to the top 

of the aquifer. The wells are then extended without casing into the aquifer to allow 

water to enter the open hole from the various layers (USGS 1988). 

The height at which water stands in a tightly cased well penetrating an artesian aquifer 

is called the potentiometric surface (Miller 1986; Murray and Halford 1996) and reflects 

the hydraulic head in the artesian aquifer. The potentiometric surface in the Lake 

Apopka Basin generally decreases in a northeasterly direction toward the Atlantic 

Ocean. It ranges from approximately 23 to 26 m (75–85 ft) NGVD 29 at the southwestern 

shore to 16 to 20 m (55–65 ft) on the northeastern shore (Knowles et al. 1995; O’Reilly et 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

21 

al. 1996). Since shallow aquifer or groundwater movement is a function of the 

permeability of deposits and the slope of the potentiometric surface, seepage enters the 

lake from the western and southern boundaries and exits the lake through the eastern 

and northern shores. 

PHYSIOGRAPHY

Lake Apopka is located at the southern edge of the Central Valley region of Florida. The 

surrounding terrain is composed of mildly rolling to undulating hills dotted with 

numerous small lakes and depressions (Figure 7). Evidence suggests that uplift has 

occurred. Since the Florida peninsula is considered tectonically stable and is in a karst 

region, this uplift may be caused by the dissolution of large volumes of limestone 

(Meyer 1983). The basin is bordered on the east by the Mount Dora Ridge and on the 

west by the Lake Wales Ridge. Ridge elevations are from 23 to 94 m (75–308 ft), and 

elevation in the Central Valley is from 18 to 27 m (59–89 ft). It is generally accepted that 

these parallel ridges were developed as beach dune systems during the higher sea 

levels of the Neogene Period (Meyer 1983), approximately 23.7–1.6 million years ago 

(McClellan and Smith 1998). 

The lake is underlain by clay, sandy clay, and sand of Miocene epoch (23.7–5.3 million 

years ago) and younger age. This layer retards water movement between the lake and 

the underlying aquifers (Anderson 1971). Generally, the organic soil in the basin is 

underlain by undifferentiated marl from the Upper Pleistocene epoch (1.6–0.01 million 

years ago) (Meyer 1983). This layer, which lies at approximately 5–15 m (15–50 ft) in 

depth, contains dark bluish gray to green clay with imbedded marine fossils. At 

approximately 15 m (50 ft), the Jackson Bluff Formation of the Lower Pliocene epoch 

(5.3–1.6 million years ago) contains unfossiliferous clayey quartz sand. Marine fossils 

are again present at about 20 m (65 ft) in a dark greenish-gray sand layer that contains 

gypsum. The Hawthorn Group lies below the 25 m (80 ft) depth. This layer, from the 

Middle Miocene epoch, contains sandy phosphatic dolomite to dolomitic phosphatic 

sand. 

Soil types within the basin range from excessively drained sandy soils located on the 

ridges to very poorly drained organic soils bordering the northern edge of Lake Apopka 

(Furman et al. 1975). Generally, soils of the uplands and low ridges are moderately well 

drained to excessively drained soils that are sandy throughout. If a weak organicstained subsoil is present, it is at a depth of greater than 1 m (40 in.) (Doolittle and 

Schellentrager 1989). Soils of the flatwoods, low ridges, and knolls are generally very 

poorly to moderately drained and have a sandy surface with an organic-stained or 

Overview of the Lake Apopka Basin 

St. Johns River Water Management District

23 

loamy subsoil, sometimes at a depth of less than 0.76 m (30 in.). The swamps, sloughs, 

and floodplains in the basin are dominated by very poorly to poorly drained organic 

soils that are subject to ponding or flooding. 

Hydrologic soil groups are used by the Natural Resources and Conservation Service 

(NRCS) to estimate runoff from precipitation (Doolittle and Schellentrager 1989). The 

groups are classified according to their intake of water, or infiltration, when the soils are 

thoroughly wet and receive precipitation for a long duration. The groups located in the 

Lake Apopka drainage basin are (Figure 8) as follows: 

• Group A Even when thoroughly wet, these soils have a high infiltration rate. 

• Group C When wet, these soils have a slow infiltration rate due to either a layer 

which impedes downward movement of water or a fine texture. 

• Group D These soils have a very slow infiltration rate due to a high permanent 

water table, a shrink-swell potential, or an impervious layer near the 

surface of the soil when thoroughly wet. 

• Group B/D These soils have a moderate infiltration rate when drained, but a very 

slow infiltration rate when undrained. 

The buildup of marsh vegetation, predominately saw grass, over thousands of years is 

responsible for the accumulation of the highly productive organic soils (peats and 

mucks). The age of the soils is approximately between 2,000 to 6,000 years, according to 

radiocarbon dating (Meyer 1983). Agriculturalists generally describe peats as fibrous 

and undecomposed, while mucks become well decomposed after tillage. Organic soils 

reached a depth up to 20 ft thick at one time on the northeastern shore of the lake (Davis 

1946). The marsh generally had shallower deposits to the northwest (6–8 ft) and the 

central portion of the marsh had deposits approximately 8–10 ft during the 1940s. 

However, subsidence has resulted in a loss of the organic layer thickness. 

Subsidence is the shrinkage, consolidation, and biological oxidation of organic soils that 

are exposed to the atmosphere through drainage and aeration. During biological 

oxidation, microbial organisms begin to break down the organic material, and nutrients 

are released. Hortenstine and Forbes (1972) compared the nutrient content of the soil 

solution from an undisturbed, swampy area and an adjacent drained, newly cleared, 

unfertilized area of an Everglades mucky peat within the Lake Apopka Basin. The 

results showed that in the drained area, inorganic phosphorus was 10 times higher and 

nitrate-nitrogen was 8 times higher in the soil solution than in the undrained area. 

These nutrients are available for release when the soil is reflooded. Other factors that 

contribute to subsidence include wind erosion, water erosion, compaction, water table 

depth, character of the organic material, and the cropping system (Lucas 1982). 

Overview of the Lake Apopka Basin 

St. Johns River Water Management District

25 

WATER QUALITY

Lake Apopka is considered the most severely polluted large Florida lake (EPA 1979). 

The lake water is well buffered, alkaline, highly turbid, and pea-green in color. The 

Secchi transparency is approximately 30 cm (12 in.) or less. Lake Apopka has received 

heavy external loading of nutrients from muck farms previously situated within the 

northern floodplain. In addition, nutrients are recycled through decomposition in the 

sediments and subsequent wind-driven mixing (internal loading). 

The Trophic State Index is a water quality index for lakes based on nitrogen and 

phosphorus concentrations, transparency, and chlorophyll a values. The index rating 

for Florida lakes ranges from 0 to 59 (good), 60 to 69 (fair), and 70 to 100 (poor) (Huber 

et al. 1982). Lake Apopka’s average Trophic State Index has varied from 82 to 91 

(poor/hypereutrophic condition) (Conrow et al. 1993). However, the 2000 Florida Water 

Quality Assessment reports an improving water quality trend (Hand et al. 2001). 

In 1995, the total phosphorus (TP) concentration began to fluctuate around a new, lower 

level (Figure 9). Chlorophyll concentrations also declined in mid-1995 and have 

continued downward trajectory (Figure 10). In fact, the January 2000 value was the 

lowest monthly average measured in a decade of SJRWMD monitoring. Secchi depth, a 

measure of water clarity, increased during the same period, showing a significant 

improving trend (Figure 11). These changes occurred during a period when average 

wind speeds measured at Lake Apopka were constant. Whether chlorophyll and Secchi 

depth have reached equilibrium with the new, lower average TP concentration or if 

chlorophyll and Secchi depth will improve further without additional P loading 

reductions is unknown. 

Chapter 62-302, F.A.C., designates Lake Apopka as a Class III water body and sets water 

quality standards for such water bodies (Lowe et al. 1995). The rule does not set specific 

numerical criteria for nutrients, but refers to “natural” and “natural background” 

conditions. Particular attention is paid to waters which are presently high in nutrient 

concentrations. The criteria for surface water quality classification (62-302.530, F.A.C.) 

address transparency by stating that “the depth of the compensation point for 

photosynthetic activity shall not be reduced by more than 10% compared to the natural 

background value.” The “compensation point” is defined as the “depth at which one 

percent of the light intensity at the surface remains unabsorbed” (62-302.200(6), F.A.C.). 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

26 

0.145

0.205

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

TP-T (mg/l)

F

Figure 9. Lake Apopka mean monthly total phosphorus, January 1987–March 2002 

64.58

92.47

0

50

100

150

200

250

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

CHLA (mg/m3)

Figure 10. Lake Apopka mean monthly chlorophyll a (uncorrected), January 1987–March 2002 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

27 

0.295

0.230

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

SECCHI (m)

Figure 11. Lake Apopka mean monthly Secchi depth, January 1987–March 2002 

Lowe et al. (1995) estimated the natural levels of these parameters and determined the 

target range for phosphorus which would allow the lake to achieve Class III conditions. 

Since the natural condition can be difficult to ascertain due to limited information, 

modern lake surveys and modeling techniques were used to determine background 

levels (Table 1). These levels are measures of annual central tendency, such as the 

median or mean, and are not meant to apply to individual measurements (Lowe et al. 

1995). 

Table 1. Most probable ranges for trophic state variables in pre-impacted and Class III 

(restored) states 

Lake Condition Total Phosphorus 

(ppb) 

Chlorophyll a

(ppb) 

Secchi Depth 

(m) 

Pre-impact 32 to 46 8 to 23 1.39 to 0.90 

Class III 38 to 55 10 to 23 1.25 to 0.81 

Note: m = meter 

 ppb = parts per billion 

Source: Lowe et al. 1995 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

28 

In 1996, the Florida Legislature created Section 373.461, FS, (Appendix A) which 

established a total phosphorus criterion of 55 parts per billion (ppb) for Lake Apopka if 

SJRWMD did not establish a rule by January 1997. SJRWMD responded with revisions 

to Chapter 40C-4, F.A.C., and the Applicant’s Handbook: Management and Storage of Surface 

Waters (Appendix A), effective August 1996. This rule established a phosphorus 

criterion of 55 ppb for Lake Apopka and discharge limitations for all activities within 

the Lake Apopka Basin permitted to discharge, directly or indirectly, into Lake Apopka, 

the Lake Level Canal, or the McDonald Canal. The phosphorus criterion specifies a 

numeric interpretation for phosphorus of the Class III narrative nutrient criterion. 

Phosphorus discharge limitations for Lake Apopka were approved by the Governing 

Board in December 2002. The rule amendments, which involve Chapters 40C-4, 40C-41, 

40C-42, and 40C-44, F.A.C., and related Applicant’s Handbooks, became effective 

March 7, 2003 (Appendix A). 

SEDIMENTS

The sediments in Lake Apopka are composed of six different layers, including an 

unconsolidated floc, a consolidated floc, peat, sand, clay, and marl (Gale and Reddy 

1994). The unconsolidated floc, which contains up to 97% water, covers 96% of the lake 

bottom to an average depth of 32 cm (1.0 ft) (Reddy and Graetz 1991). The high 

sedimentation rate is due to the abundance of nutrients being assimilated by algae. 

Upon their death, algal cells are deposited on the sediment surface, thus resulting in 

sediment buildup (Reddy et al. 1988). 

Schelske (1997) concluded that phosphorus storage in the sediments has increased at 

least threefold in the last 50 years, based on comparisons by decade, and as much as 

fourfold if annual rates are compared. Sediment porewater nutrient levels are high and 

may provide the primary internal recycling of phosphorus for the lake through windinduced mixing. Reddy and Graetz (1991) estimated the mass of total phosphorus stored 

in the unconsolidated floc was 1,371 metric tons. More than 5,200 tons was stored in the 

consolidated floc layer. 

BIOTA

The biota of Lake Apopka reflect its chemical status. Blue-green algae dominate the 

water column throughout the year. The limited amount of emergent vegetation is 

predominantly cattails (Typha spp.), with some stands of bulrush (Scirpus spp.) and knot 

grass (Paspalidium geminatum) interspersed around the lake shoreline. In 1995, several 

small patches of eelgrass (Vallisneria americana) were observed near the north shore. By 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

29 

January 2001, 83 patches of submergent vegetation, primarily eelgrass, totaling about 

2.6 ha (6.5 ac) had been discovered around the lake, and small areas of musk-grass 

(Chara spp.) and southern naiad (Najas guadalupensis) were found and are being 

monitored for expansion. 

The dominant zooplankton in the lake are smaller members of the water fleas 

(Cladocera) and rotifers (Crisman and Beaver 1988). Benthic invertebrate populations in 

the lake are low in diversity and density and are composed primarily of sludgeworms 

(tubificids) and midges (chironomids) (Brezonik et al. 1978). Most of the taxa in the lake 

are pollution-tolerant forms that can endure high levels of organic enrichment (Belanger 

1979). The fish community is dominated by gizzard shad (Dorosoma cepedianum) and 

blue tilapia (Tilapia aurea) with remnant populations of sunfish (Centrarchidae). An active 

commercial fishery for catfish (Ictaluridae) existed in the lake until the early 1990s. That 

fishery has subsequently declined. 

Several animal and plant species that occur or may occur in the Lake Apopka Basin 

have special protection status with federal and state agencies. These species are listed in 

Tables 2 and 3. All species listed may not be present within the immediate confines of 

the Lake Apopka Basin. The abundance of bird species that utilize the basin was 

apparent by a one-day visit in 1994 by Southeast Nature Tours to Zellwood Farms, 

where 70 different species of birds were sighted (Ganong 1994). Stenberg et al. (1998) 

reported 71 bird species during investigations in the demonstration marsh flow-way 

from 1990 through 1994. In 1998, the Zellwood/Mount Dora Christmas Bird Count 

recorded a likely North American inland record of 174 species (Cornell University 

2002). Table 4 lists the birds observed at the Lake Apopka restoration site by SJRWMD 

personnel and volunteers. 

LAND USE/LAND COVER

Land Use 

Land use activity and development in a basin usually combine with regional geology to 

determine the quality of water in a receiving water body. In 1995, agriculture covered 

21,626 ha (53,437 ac) of the 48,471 ha (119,773 ac) within the Lake Apopka drainage 

basin (Figure 12). Surface waters covered approximately 13,794 ha (34,084 ac). The 

remaining 19,353 ha (22,252 ac) was composed of wetland, forest, rangeland, urban 

development, and barren land. These land use/land cover categories are defined in 

Appendix D. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

30 

Table 2. Animal species that may occur in the Lake Apopka Basin and that have been granted 

special status by federal or state agencies 

Common Name Scientific Name Category 

Fish

Lake Eustis pupfish* Cyprinodon varigatus hubbsi SSC 

Southern tesselated darter* Etheostoma olmstedi maculaticeps SSC 

Reptiles and Amphibians 

American alligator Alligator mississippiensis SSC 

Eastern indigo snake Drymarchon corais couperi FT, ST 

Bluetailed mole skink Eumeces egregious lividus FT, ST 

Gopher tortoise Gopherus polyphemus SSC 

Sand skink Neoseps reynoldsi FT, ST 

Florida pine snake Pituophis melanoleucus mugitus SSC 

Gopher frog Rana capito SSC 

Short tailed snake Stilosoma exenuatum ST 

Mammals 

Florida panther Felis concolor coryi FE, SE 

Florida mouse Podomys floridanus SSC 

Sherman’s fox squirrel Sciurus niger shermani SSC 

Florida black bear Ursus americanus floridanus ST 

Birds 

Roseate spoonbill Ajaia ajaja SSC 

Florida scrub jay Aphelocoma coerulescens FT, ST 

Limpkin Aramus guarauna SSC 

Florida burrowing owl Athene cunicularia floridana SSC 

Little blue heron Egretta caerulea SSC 

Snowy egret Egretta thula SSC 

Tricolored heron Egretta tricolor SSC 

White ibis Eudocimus albus SSC 

Arctic peregrine falcon Falco peregrinus tundrius SE 

Southeastern American kestrel Falco sparverius paulus ST 

Whooping crane Grus americana SSC, FT (E/P) 

Florida sandhill crane Grus canadensis pratensis ST 

Southern bald eagle Haliaeetus leucocephalus leucocephalus FT, ST 

Wood stork Mycteria americana FE, SE 

Red-cockaded woodpecker Picoides borealis FE, ST 

Audubon’s crested caracara Polyborus plancus audubonii FT, ST 

Snail kite Rostrhamus sociabilus plumbeus FE, SE 

Black skimmer Rynchops niger SSC 

Least tern Sterna antillarum ST 

*These fish species have not been found in Lake Apopka 

Source: FWC 1997; Peterson 1997; USFWS 2001 

Status code: 

 FE = federal endangered FT = federal threatened 

 E/P = experimental population SE = state endangered 

 SSC = species of special concern ST = state threatened 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

31 

Table 3. Plant species that may occur in the Lake Apopka Basin and that have been granted special 

status by federal or state agencies 

Common Name Scientific Name Category 

Curtiss’ milkweed Asclepias curtissii SE 

Florida bonamia Bonamia grandiflora FT, SE 

Ashe’s savory Calamintha ashei ST 

Pygmy fringe-tree Chionanthus pygmaea FE, SE 

Pigeon wings (butterfly pea) Clitoria fragrans FT, SE 

Short-leaved rosemary Conradina breviflora FE, SE 

Large-flowered rosemary Conradina grandiflora SE 

Beautiful pawpaw Deeringothamnus pulchellus FE, SE 

Scrub mint Diceranda frutescens FE, SE 

Water sundew Drosera intermedia ST 

Scrub buckwheat Eriogonum floridanum FT, SE 

Harper’s beauty Harperocallis flava FE, SE 

Florida hartwrightia Hartwrightia floridana ST 

Florida hasteola Hasteola rovertiorum SE 

Yellow star anise Illicium parviflorum SE 

Cooley’s water willow Justica cooleyi SE, FE 

Nodding pinweed Lechea cernua ST 

Catesby’s lily Lilium catesbaei ST 

Bog spicebush Lindera subcoriacea SE 

Cardinal flower Lobelia cardinalis ST 

Scrub lupine Lupinus westianus var. aridorum FE, SE 

Florida milkweed Matela floridana SE 

Pinesap Monotropa hypopithys SE 

Slender naiad Najas filifolia ST 

Fall flowering pleat-leaf Nemastylis floridana SE 

Florida beargrass Nolina atopocarpa ST 

Scrub beargrass (Britton’s beargrass) Nolina brittoniana FE, SE 

Hand adder’s tongue fern Ophioglossum palmatum SE 

Papery whitlow-wort Paronychia chartacea FT, SE 

Pepper Peperomia humilus SE 

Southern yellow fringeless orchid Platenthera integra SE 

Lewton’s polygala Polygala lewtonii SE, FE 

Small’s jointweed (sand lace) Polygonella myriophylla FE, SE 

Scrub plum Prunus geniculata FE, SE 

Wild coco Pteroglossaspis ecristata ST 

Needle palm Rhapidophyllum hystix SSC 

Florida willow Salix floridana SE 

Hidden stylisma Stylisma abdita SE 

Clasping warea (wide-leaf warea) Warea amplexifolia FE, SE 

Carter’s mustard Warea carteri FE, SE 

East Coast coontie Zamia umbrosa C 

Simpson’s zephyr lily Zephyranthes simpsonii ST 

Source: FWC 1997; Peterson 1997; USFWS 2001 

Status code: 

 FE = federal endangered FT = federal threatened 

 E/P = experimental population SE = state endangered 

 SSC = species of special concern ST = state threatened 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

32 

Table 4. Bird species observed at the Lake Apopka restoration site 

LOONS AND GREBES DUCKS, GEESE, SWANS RAILS, GALLINULES, COOTS, CRANES

Pied-billed grebe Blue-winged teal Limpkin 

Horned grebe Cinnamon teal Sandhill crane 

Eared grebe Northern shoveler Whooping crane 

PELICANS AND ALLIES Northern pintail PLOVERS AND SANDPIPERS

American white pelican Green-winged teal Black-bellied plover 

Brown pelican Canvasback American golden plover 

Double-crested cormorant Redhead Semipalmated plover 

Anhinga Ring-necked duck Killdeer 

HERONS, IBISES, AND ALLIES Greater scaup Black-necked stilt 

American bittern Lesser scaup American avocet 

Least bittern Bufflehead Greater yellowlegs 

Great blue heron Hooded merganser Lesser yellowlegs 

Great white heron Red-breasted merganser Solitary sandpiper 

Great egret Ruddy duck Willet 

Snowy egret HAWKS AND ALLIES Spotted sandpiper 

Little blue heron Osprey UPLAND SANDPIPER

Tricolored heron Swallow-tailed kite Whimbrel 

Reddish egret White-tailed kite Long-billed curlew 

Cattle egret Snail kite Marbled godwit 

Green heron Bald eagle Ruddy turnstone 

Black-crowned night-heron Northern harrier Red knot 

Yellow-crowned night-heron Sharp-shinned hawk Sanderling 

White ibis Cooper’s hawk Semipalmated sandpiper 

Scarlet ibis Red-shouldered hawk Western sandpiper 

Glossy ibis Broad-winged hawk Least sandpiper 

Roseate spoonbill SHORT-TAILED HAWK White-rumped sandpiper 

STORKS AND VULTURES Swainson’s hawk Baird’s sandpiper 

Wood stork Red-tailed hawk Pectoral sandpiper 

Black vulture Rough-legged hawk Dunlin 

Turkey vulture Golden eagle Curlew sandpiper 

DUCKS, GEESE, SWANS Crested caracara Stilt sandpiper 

Black-bellied whistling-duck American kestrel Buff-breasted sandpiper 

Fulvous whistling-duck Eurasian kestrel Ruff 

White-faced whistling-duck Merlin Short-billed dowitcher 

Greater white-fronted goose Peregrine falcon Long-billed dowitcher 

Snow goose TURKEYS AND QUAIL Common snipe 

Ross’ goose Wild turkey American woodcock

Canada goose Northern bobwhite Wilson’s phalarope 

Muscovy duck RAILS, GALLINULES, COOTS, CRANES Red-necked phalarope 

Wood duck King rail GULLS, TERNS, AND ALLIES

Gadwall Virginia rail Laughing gull 

American wigeon Sora Franklin’s gull 

American black duck Purple gallinule Bonaparte’s gull 

Mallard Common moorhen Ring-billed gull 

Mottled duck American coot Herring gull 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

33 

Table 4—Continued

GULLS, TERNS, AND ALLIES FLYCATCHERS KINGLETS AND GNATCATCHERS

Lesser black-backed gull Eastern wood-pewee Golden-crowned kinglet 

Gull-billed tern Acadian flycatcher Ruby-crowned kinglet 

Caspian tern Willow flycatcher Blue-gray gnatcatcher

Royal tern Least flycatcher STARLINGS, PIPITS, WAXWINGS

Common tern Eastern phoebe European starling 

Forster’s tern Vermillion flycatcher American pipit 

Least tern Ash-throated flycatcher Cedar waxwing 

Black tern Great-crested flycatcher Wood Warblers and Allies 

Black skimmer Cassin’s kingbird Blue-winged warbler 

PIGEONS AND DOVES Western kingbird Tennessee warbler 

Rock dove Eastern kingbird Orange-crowned warbler 

Eurasian-collared dove Gray kingbird Nashville warbler 

White-winged dove Scissor-tailed flycatcher Northern parula 

Mourning dove Fork-tailed flycatcher Yellow warbler 

Common ground-dove SHRIKES Chestnut-sided warbler 

CUCKOOS AND ANIS Loggerhead shrike Magnolia warbler 

Black-billed cuckoo VIREOS Cape May warbler 

Yellow-billed cuckoo White-eyed vireo Black-throated blue warbler 

Groove-billed ani Bell’s vireo Yellow-rumped warbler 

OWLS AND GOATSUCKERS Yellow-throated vireo Black-throated green warbler 

Barn owl Blue-headed vireo Blackburnian warbler

Eastern screech-owl Philadelphia vireo Yellow-throated warbler 

Great horned owl Red-eyed vireo Pine warbler 

Barred owl JAYS AND CROWS Prairie warbler 

Short-eared owl Blue jay Palm warbler 

Lesser nighthawk Florida scrub jay Bay-breasted warbler 

Common nighthawk American crow Blackpoll warbler 

Chuck-will’s-widow Fish crow Cerulean warbler 

Whip-poor-will SWALLOWS Black-and-white warbler 

SWIFTS, HUMMINGBIRDS, Purple martin American redstart 

AND KINGFISHERS Tree swallow Prothonotary warbler 

Chimney swift Northern rough-winged swallow Worm-eating warbler 

Ruby-throated hummingbird Bank swallow Ovenbird 

Black-chinned hummingbird Cliff swallow Northern waterthrush 

Belted kingfisher Barn swallow Louisiana waterthrush 

WOODPECKERS CHICKADEES AND TITMICE Kentucky warbler 

Red-headed woodpecker Carolina chickadee Common yellowthroat 

Red-bellied woodpecker Tufted titmouse Hooded warbler 

Yellow-bellied sapsucker WRENS AND BUBULS Yellow-breasted chat 

Downy woodpecker Carolina wren Wilson’s warbler 

Hairy woodpecker Bewick’s wren Sparrows 

Northern flicker House wren Eastern towhee

Pileated woodpecker Sedge wren Chipping sparrow 

 Marsh wren Clay-colored sparrow 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

34 

Table 4—Continued

SPARROWS Grosbeaks and Allies Blackbirds and Allies

Field sparrow Lapland longspur Bobolink 

Vesper sparrow Northern cardinal Red-winged blackbird 

Lark sparrow Rose-breasted grosbeak Eastern meadowlark 

Lark bunting (unverified) Blue grosbeak Yellow-headed blackbird 

Savannah sparrow Indigo bunting Rusty blackbird 

Grasshopper sparrow Painted bunting Common grackle 

Henslow’s sparrow Dickcissel Boat-tailed grackle 

Le Conte’s sparrow THRUSHES AND ALLIES Shiny cowbird 

Fox sparrow Veery Bronzed cowbird

Song sparrow Gray-cheeked thrush Brown-headed cowbird 

Lincoln’s sparrow Bicknell’s thrush Orchard oriole 

Swamp sparrow Swainson’s thrush Baltimore oriole 

White-throated sparrow Hermit thrush Finches and Allies 

White-crowned sparrow Wood thrush American goldfinch 

Tanagers American robin OLD WORLD SPARROWS

Summer tanager Gray catbird House sparrow 

Scarlet tanager Northern mockingbird 

 Brown thrasher 

Source: Robinson 2000, 2001; SJRWMD staff reports (unpublished)

Due to multicropping, nearly 10,449 ha (25,800 ac) of total crops were harvested in 1996 

within the muck farm area of 5,913 ha (14,600 ac), located on the lake’s former 

floodplain. The estimated average economic value of the 1991–95 harvests totaled 

approximately $62 million in direct annual sales (Apogee, Inc. 1996). A wide variety of 

vegetable crops were produced, including sweet corn, carrots, celery, cucumbers, 

cabbage, radishes, and other vegetables. During the early 1990s, Florida was the third 

highest state in the nation in fresh market carrot production and first in sweet corn 

production (Crnko et al. 1993). Statewide, approximately 90% of the carrots and 25% of 

the sweet corn were grown in the central Florida agricultural area around Zellwood 

(Crnko et al. 1993). 

Due to soil subsidence, oxidation, and compaction, the former farm area lies 

approximately 1 m (3 ft) below the surface of the lake and is protected from flooding by 

a levee. The area was drained by a system of field ditches, canals, and large pumps. 

When water was required for irrigation or flooding of fields for pest control, water from 

the lake was used. During periods of excess rainfall, water was pumped back into the 

lake. The installation of detention ponds on several farms allowed recycling of water on 

the farm and greatly reduced pumping to Lake Apopka (Stites et al. 2001). 

SWIM Plan for Lake Apopka 

St. Johns River Water Management District

36 

Citrus production on the eastern and western slopes of the lake peaked during the 

1979–80 season, then declined quickly after killing freezes in December 1983 and 

January 1985. Trees on the south shore of Lake Apopka had minimum damage during 

the Christmas freeze of 1983 (Attaway 1997). However, the 1985 freeze produced 

temperatures below -5.6°C (22°F) for more than 6.5 hours in Groveland, just 15 miles 

west of Lake Apopka (Attaway 1997). The combined effects of the two severe freezes 

plus earlier freezes in 1981 and 1982 killed many acres of citrus trees. 

Population growth is rapid within the basin (Table 5). For example, the population of 

Apopka grew approximately 96% from 1990 to 2000 (UF 2001). In 1996, Orange County 

Table 5. Population by municipality within the Lake Apopka Basin 

City April 1, 1990 

(census) 

April 1, 2000 

(census) 

Total Change 

1990–99 

Percent Change

1990–99 

Apopka 13,611 26,642 13,031 +96 

Montverde 890 882 -8 -0.9 

Oakland 700 936 236 +34 

Winter Garden 9,863 14,351 4,488 +46 

Source: UF 2001 

was estimated to be the fourth fastest growing county in the state and was ranked as the 

sixth most populated county in Florida. By 2010, Orange County is projected to have a 

population of 1.1 million, based on a growth rate of 24% since 1990 (UF 2001). During 

the same time period, it is projected that the population of Lake County will grow by 

26%, to 264,800. 

Land Cover—Wetlands 

Freshwater wetlands still cover approximately 8% of the land in the basin (Figure 13), 

and include swamps, bayheads, flatwoods depressions, deep marshes, and shallow 

marshes. Freshwater swamps are dominated by woody species such as cypress, red 

maple, sweetgum, and black tupelo. Freshwater depressions, marshes, sloughs, and 

artificial drainage ways are usually dominated by herbaceous and shrub species 

including grasses, sedges, rushes, ferns, buttonbush, Coastal Plain willow, primrose 

willow, cattail, saw grass, water lilies, submersed aquatics, and other water-tolerant 

plants. 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

37 

Other: Rangeland; forests; barren land; and transportation, 

communication and utilities

3% 6%

8%

28%

45% 10%

Not mapped

Other

Wetlands

Urban or

developed

Water 

Agriculture

Figure 13. 1995 land use/land cover composition 

RECREATION AND PUBLIC USE

Lake Apopka supported a very popular sport and commercial fishery during the early 

portion of the twentieth century. In 1950, fish camps could accommodate over 300 

overnight guests, and nearly 200 fishing boats were available for hire (Apogee, Inc. 

1996). The estimated economic values of recreational and commercial fishing were 

estimated to be over $1 million and $250,000, respectively, in 1951 dollars. Largemouth 

bass, black crappie, and panfish were popular with sport fishermen, while the 

commercial interests targeted turtles and catfish. Between 1956 and 1965, the number of 

fish camps dwindled from 21 to 9 (Heaney et al. 1989). 

Currently, the recreational facilities on Lake Apopka include Magnolia Park on the 

southwest shore, Winter Garden City Park and the Oakland Nature Park on the south 

shore, and a small public boat ramp in Montverde located on the southwest shore of the 

lake (see Figure 3). According to a 1996 economic analysis by Apogee, Inc., the Lake 

Apopka recreational sport fishery is well below usage levels of other nearby lakes. The 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

38 

aesthetic quality of the lake discourages all water contact sports, such as swimming and 

skiing (Conrow et al. 1993). Recreational boating is well under-utilized, and there is 

limited opportunity for waterfowl hunting or bird watching (Apogee, Inc. 1996). 

NUTRIENT POLLUTION SOURCES

Farms located in Lake and Orange counties on the northern shore of Lake Apopka 

(Figure 14) were historically the largest contributors of nutrient loading to the lake 

(Figure 15). SJRWMD estimates are that, until recently, farming operations discharged 

over 20 billion gallons of water annually for drainage, flood control, and pest control. 

The quality of this discharge water (one third of the lake’s total volume) was poor due 

to high concentrations of nutrients. For example, the average mean volume-weighted 

TP concentration in farm discharges from 1989 to 1994 was 0.897 milligrams per liter 

(mg/L) (Stites et al. 2001). During that same time period, the farms contributed 

approximately 85% of the net phosphorus loading to Lake Apopka. During the late 

1980s, SJRWMD entered into consent order agreements with the major farming 

interests, A. Duda and Sons and ZDWCD, which were designed to reduce discharges 

and improve water quality according to a fixed time schedule. 

Ultimately, the farms were purchased following the passage of legislation in 1996, 

which determined that it was in the public interest for SJRWMD to pursue buyout of 

the farms to reduce phosphorus loading to the lake. The SJRWMD acquisition of the 

farms was completed in August 1999 using federal and state funds. The area will be 

restored to wetlands and, ultimately, reconnected to the lake. 

The degree to which nonpoint pollution sources other than agriculture contribute to 

problems in the lake is presently small. An inventory of permitted nonpoint discharges 

(Chapter 373, Part IV, permits) is found in Appendix E. The relative contribution of 

pollutants from other nonpoint sources will increase as agricultural sources are 

successfully controlled. 

Discharges to the lake from industrial or domestic point sources have been reduced 

over time. Since 1980, the City of Winter Garden Wastewater Treatment Facility has 

utilized a percolation/evaporation system for land application of its effluent, with no 

direct discharge to the lake. In 1996, the plant had an average daily flow of 

approximately 1.35 million gallons per day (mgd) and a capacity of 2.0 mgd. Currently, 

groundwater seepage moves through underdrains to an unnamed ditch and then flows 

through approximately one mile of wetlands and swamp to Lake Apopka. A proposed 

expansion to the plant would increase the total permitted capacity to 2.5 mgd, with a 

total design capacity of 4.0 mgd. Mining of peat deposits on approximately 170 ha 




 	



 

	



	





 










	





 !

 !

	





	






 



 



   

Apopka-Beauclair 

Canal 

9.95 

Muck farms 

52.13 

(84.94%) Atmospheric

deposition 

5.03 

(8.20%) 

Overland runoff 

.60 

(0.98%) 

Tributaries 

1.45 

(2.36%) 

Point sources 

.64 

(1.04%) 

Bottom seepage 

.06 

Net storage 

in sediments: 

51.39 

Apopka Spring 

1.00 

(1.63%) 

Lateral seepage 

.52 

(0.85%) 

Figure 15. 

External phosphorus budget for Lake Apopka 

1989-94 (all values are mean annual fluxes in metric tons) 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

41 

(425 ac) on Pine Island by the Scotts Hyponex Corporation consistently discharged 

approximately 1–1.5 billion gallons annually until the digging operation was closed in 

late 1997. This reduced annual phosphorus loading to the lake by approximately 350 

kilograms (kg). Winter Garden Citrus Products constructed percolation ponds and 

spray fields in 1977, which limited the plant’s surface water discharge to approximately 

2.5 mgd. 

All current point sources are listed in Appendix E. 

TOXIC POLLUTANTS

The Zellwood groundwater contamination site, a 23-ha (57-ac) Superfund site, is located 

approximately one-half mile west of Zellwood (EPA 2001). Due to past waste disposal 

practices by four separate industries, groundwater, sediments, soil, and sludges at the 

site became contaminated with organic compounds including polycyclic aromatic 

hydrocarbons, pesticides, and heavy metals. Abandoned drums were removed and 

contaminated soil was excavated and solidified on-site. However, a plume of 

groundwater contamination containing metals and nutrients is present in the surficial 

aquifer and extends several hundred feet south of West Jones Avenue. A baseline risk 

assessment for human health indicated an unacceptable risk to human health would 

occur only if future residents/businesses were to use the shallow groundwater at and 

around the site for drinking water. The selected remedy is monitored natural 

attenuation with institutional controls. 

From 1957 to 1981, Tower Chemical Company (TCC) manufactured, produced, and 

stored various pesticides (EPA 2002a). TCC discharged wastewater into a 0.5-ac unlined 

percolation/evaporation pond which was located over a relict sinkhole that created a 

conduit to the Floridan aquifer. Waste was burned and buried on a 1.5-ac plot. In 1980, 

following an overflow from a wastewater pond into Gourd Neck, TCC constructed a 

spray irrigation field for waste disposal that was not permitted by the state. TCC ceased 

operations following two court orders that prohibited the use of the sprayfield and of 

DDT. Following the spill, vegetation changes and a fish kill were reported within the 

Gourd Neck area of Lake Apopka (Rice and Percival 1996). The area was later 

designated a Superfund site by the U.S. Environmental Protection Agency (EPA) due to 

the presence of copper and pesticides, including DDT, in on-site surface and subsurface 

soils, groundwater (including the surficial aquifer and the deeper Floridan aquifer), and 

the on-site pond. Also, pesticides contaminated on- and off-site sediments and volatile 

organic compounds, including ethyl benzene, were present in on-site soils. To prevent 

contaminants from entering the Floridan aquifer, 1,720 cubic meters (m3

) (2,275 cubic 

yards [yd3

]) of contaminated soil, 1,170 m3 (1,545 yd3) of sediment, and 72 drums were 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

42 

excavated and disposed of off-site in 1983 by EPA. In addition, over a million gallons of 

wastewater was pumped from the pond and treated, soil that was removed was 

replaced by clean fill, and a surface water runoff system was constructed to prevent 

migration of the contaminants off-site. The most recent groundwater data show that 

pesticides and other organic contaminants persist in the groundwater. Soil data from 

March 1997 show DDT and its metabolites are present to a depth of 8.5 m (28 ft) below 

ground surface (EPA 2002a). Monitoring of nearby potable wells was also initiated. An 

Interim Action Record of Decision, which provides an alternate water supply to the 

nearby residents, was signed in August 2000, but has not yet been funded (EPA 2002a). 

A baseline risk assessment was completed in 2001. EPA is currently analyzing 

tentatively identified and unknown compounds and determining their toxicity. The 

investigation is centering on improving the identification and quantification of 

dichlorobenzophene (DBP), a degradation product of DDT, which was used by TCC to 

formulate miticides for the citrus industry (EPA 2002b). 

In 1981, a major decline was observed in juvenile alligator abundance in Lake Apopka 

(Woodward et al. 1993). An analysis of alligator eggs collected in 1985 showed that eggs 

from Lake Apopka had significantly elevated levels of DDD, DDT, and DDE (Rice and 

Percival 1996). These compounds and many other pesticides can act as hormones or as 

inhibitors of natural hormones in developing embryos (Guillette et al. 1994). U.S. Fish 

and Wildlife Service (USFWS), University of Florida (UF), and FWC researchers 

identified reproductive failure in alligator and turtle populations in the lake and found 

a possible link to DDE and other organic contaminants. Such compounds are found in 

low concentrations in Lake Apopka sediments. However, recent research by Gross et al. 

(1998) does not support the earlier hypothesis of a DDT or DDE link to clutch viability. 

Two distinct alligator populations have been found in the lake (Gross et al. 1998). 

Clutches from the southern portion of Lake Apopka had higher nested egg numbers, 

hatched egg numbers, neonatal survivor numbers, viability rate, hatch rate, and 

production rate than clutches from the northern portion of Lake Apopka. According to 

Rice and Percival (1996), an increasing overall trend in the juvenile population and in 

clutch viability has occurred on Lake Apopka since 1989. They suggest two very 

different potential fates for alligators (and other vertebrate populations) in Lake 

Apopka. Either the system, damaged in the past by environmental contamination or 

other causes, is in recovery, or this apparent recovery phase may end, and juvenile 

animals present today might not reproduce or survive. 

Overall, the studies of wildlife on Lake Apopka indicate altered reproductive function 

for alligators, turtles, and possibly largemouth bass. Research conducted by the UF has 

indicated that contaminant-induced endocrine disruption occurs in wildlife, specifically 
Overview of the Lake Apopka Basin 

St. Johns River Water Management District

43 

fish and alligators, and several effective biomarkers have been identified to study these 

effects. 

As a result of previous findings, FDEP (at that time, FDER) contracted with the UF in 

1986 to conduct a survey of toxic organic chemical compounds in aquatic sediments and 

tissues of aquatic organisms throughout the state (Delfino et al. 1987). Sediments 

sampled in Lake Apopka contained low levels of DDT-related residues. Catfish tissue 

also showed low levels of DDT-related residues, although these low concentrations do 

not generally pose a threat to consumers of the fish. The findings were in general 

agreement with previous analyses. 

During 1990 and 1991, a survey of levels and potential toxic effects of substances 

specifically in Lake Apopka sediments was conducted (Segal and Pollman 1991). 

Sediment cores from two depths at 10 locations were analyzed for the 152 elements and 

compounds on the EPA Toxic Compounds List. Thirteen elements occurred in 

sufficiently high concentrations to warrant a detailed examination; two—copper and 

lead—appear to pose the greatest threat of toxicity to the lake biota. Due to the complex 

interactions that occur in biological systems, the potential toxic effects of these elements 

were difficult to assess. 

Prior to SJRWMD purchase of the muck farm properties on the north shore of Lake 

Apopka, all properties received an environmental site assessment (ESA) in accordance 

with the American Society for Testing and Materials Standard E1527. The ESA and 

subsequent remediation activities identified and removed highly contaminated soil 

from the farms in accordance with a site-specific cleanup plan. 

In addition to the ESA, SJRWMD also conducted an environmental risk assessment to 

evaluate the potential for long-term (chronic) risk for wildlife from the average residual 

pesticide levels expected to remain in the farm soils after remediation was completed. 

The risk assessment and a subsequent follow up evaluation indicated no likelihood that 

background residual pesticide levels would present an acute toxicity risk to aquatic or 

wetland animals. Some concerns about long-term, sub-lethal effects on growth or 

reproduction were raised, and SJRWMD planned a monitoring program to assess these 

potential problems during restoration. 

In late November 1998, unusually high bird mortality, especially among American 

white pelicans, was observed in one area of the former farmlands. Over a period of four 

months, 441 American white pelicans, 43 wood storks, 34 great egrets, 58 great blue 

herons, and smaller numbers of 20 other bird species died on-site. On February 17, 1999, 

USFWS issued a press release with a preliminary conclusion that the birds had died 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

44 

from poisoning by organochlorine pesticides, including toxaphene, dieldrin, and DDT 

and its metabolites. 

SJRWMD and NRCS launched an investigation of the bird mortality event in early 1999. 

To aid in the investigation of the mortality event, SJRWMD convened a team of experts 

from 13 federal, state, county, and private organizations to create a technical advisory 

group. Approximately 1,300 water, soil, and wildlife tissue samples were analyzed to 

help identify the chain of events that led to the bird mortality. More detailed 

information concerning this issue is available in the Progress of the Lake Apopka 

Restoration Program section. 

In 1999, the Florida Department of Health evaluated human exposures from ingestion 

of fish from Lake Apopka. They evaluated the concentrations of 30 different pesticides 

and 30 different metals in the edible fillet portions of brown bullhead catfish, white 

catfish, largemouth bass, and blue tilapia. The risk assessment established the cancer 

risk for an individual who consumes fish from a source at 30 grams per day, 350 days 

per year, for 30 years. Based on their findings, they issued an advisory for brown 

bullhead catfish and recommended that consumption be limited to one 8-ounce fillet 

every two weeks. 
Governmental Jurisdiction 

St. Johns River Water Management District

45 

GOVERNMENTAL JURISDICTION

Numerous governmental agencies have jurisdiction within the Lake Apopka Basin. 

Section 373.453(2)(b), FS, requires that the SWIM Plan contain an “identification of all 

governmental units that have jurisdiction over the water body and its drainage basin 

within the approved surface water improvement and management plan area, including 

local, regional, state, and federal units.” A complete directory of addresses is found in 

Appendix F. 

FEDERAL

U.S. Environmental Protection Agency 

EPA was created under Reorganization Plan 3 of 1970 to consolidate the federal 

government’s environmental regulatory activities under the jurisdiction of a single 

agency. The majority of environmental regulations are contained in United States Code, 

Title 40—Protection of the Environment. EPA administers several major programs 

based on specific legislation, including the Clean Water Act, the Safe Drinking Water 

Act, the Resource Conservation and Recovery Act (RCRA), the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA or Superfund), 

and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). EPA issues 

National Pollutant Discharge Elimination System (NPDES) permits and air quality 

permits. In Florida, FDEP assumed the administration of the NPDES stormwater 

program beginning in October 2000, except in Indian country lands. EPA also issues 

permits and reviews permits issued by FDEP for the treatment, disposal, and storage of 

hazardous wastes. EPA reviews USACE permit activities, sets minimum water quality 

standards, and sets guidelines for state environmental programs. 

U.S. Department of Agriculture (USDA) 

• The Natural Resources and Conservation Service (NRCS), formerly the Soil Conservation 

Service (SCS), was authorized by the Federal Crop Insurance Reform and Department 

of Agriculture Reorganization Act of 1994. NRCS works with private landowners on 

their lands to help them conserve natural resources. NRCS has responsibility for the 

three major areas covered by SCS: soil and water conservation, natural resource 

surveys, and community resource protection and management. In addition, NRCS 

administers the Wetlands Reserve Program (WRP) in consultation with the Farm 

Service Agency and other federal agencies. WRP is a voluntary program to restore and 

protect wetlands on private property. Landowners who choose to participate in WRP 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

46 

may sell a conservation easement or enter into a cost-share restoration agreement with 

USDA to restore and protect wetlands. 

• The Consolidated Farm Service Agency (FSA) is a new USDA agency formed in 1994 

consisting of the Agricultural Stabilization and Conservation Service, Farmer’s Home 

Administration, and NRCS. FSA provides administration of farm commodity 

programs, operating and emergency loans, conservation and environmental programs, 

emergency and disaster assistance, domestic and international food assistance, and 

international export credit programs. FSA provides support at a local level to help 

protect wetlands and solve water, woodland, and pollution problems on farms and 

ranches. 

U.S. Department of the Interior 

• The U.S. Fish and Wildlife Service (USFWS) is responsible for the protection and 

improvement of fish and wildlife and their habitats and has jurisdiction over federally 

listed threatened, endangered, and migratory species. USFWS reviews U.S. Army 

Corps of Engineers (USACE) permits for effects on fish and wildlife, conducts 

environmental research, manages migratory birds, and performs law enforcement. 

• The U.S. Geological Survey (USGS) monitors surface and subsurface water resources, 

including lake levels, river and stream flow, water quality, and water use. USGS 

conducts and publishes results of hydrogeological research and maps related to 

topography, landforms, and hydrology. The Orlando subdistrict office of USGS is 

responsible for the collection of hydrologic data and interpretive studies of hydrology 

in central and northeast Florida. This work is conducted in cooperation with the St. 

Johns River, South Florida, and Southwest Florida water management districts, other 

federal agencies, counties, and other municipalities. 

U.S. Army Corps of Engineers 

USACE is responsible for construction, maintenance and planning of navigation, flood 

control, shore protection, recreation, and implementation of specific environmental 

restoration projects. USACE and FDEP regulate dredge and fill permits in Florida 

waters using a joint application, but under separate authorities and programs. 

Federal Emergency Management Agency (FEMA) 

FEMA advises on building codes and floodplain management; assists with local and 

state emergency preparedness; coordinates the federal response to disasters; trains 
Governmental Jurisdiction 

St. Johns River Water Management District

47 

emergency managers; administers the national flood insurance program; and makes 

disaster assistance available to states, communities, businesses, and individuals. 

U.S. Department of Commerce 

The Department of Commerce promotes job creation, economic growth, sustainable 

development, and improved living standards by working in partnership with business, 

universities, communities, and workers. 

• The mission of the National Oceanic and Atmospheric Administration (NOAA) is to 

describe and predict changes in the Earth’s environment and wisely manage the 

nation’s coastal and marine resources. 

• The National Weather Service (NWS) is part of NOAA. NWS delivers climate, 

analysis, and forecast products and conducts research to improve the understanding 

and stewardship of the environment. 

U.S. Department of Transportation 

The U.S. Coast Guard assumed responsibility for bridges in 1967 when moved into the 

Department of Transportation from USACE. The Coast Guard is responsible for 

approval of the location and plans of bridges and causeways constructed across 

navigable waters of the United States. 

STATE

Florida Department of Environmental Protection (FDEP) 

In 1993, the Departments of Natural Resources (FDNR) and Environmental Regulation 

(FDER) were consolidated to form FDEP. The regulatory responsibilities of FDER 

relating to water resources were assumed by FDEP. FDEP’s primary responsibility is to 

preserve the environmental integrity of Florida’s air, water, and land resources. The 

department has permit jurisdiction over point and nonpoint source discharges, some 

MSSW, some dredge and fill, hazardous and solid wastes, drinking water systems, power 

plant siting, mines, and many construction activities in waters of the state. FDEP interacts 

closely with other state and federal agencies on water-related matters. 

FDEP has also assumed the responsibilities of the former FDNR, including the 

administration of all state lands, including parks and aquatic preserves; land 

acquisition; enforcement for the Florida Endangered Species Act and the Oil Spill 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

48 

Prevention and Pollution Control Act; coordination of aquatic plant research and 

control in the state; issuance of permits for transport of aquatic plants; and for herbicide 

spraying and other plant control methods in aquatic environments. 

The Florida Wetland Information Center utilizes ecosystem management and ecological 

principles to develop a framework for a statewide ecological restoration program for 

wetlands and their associated uplands. 

Florida Fish and Wildlife Conservation Commission (FWC) 

The Florida Game and Fresh Water Fish Commission and the Marine Fisheries 

Commission were replaced with FWC July 1, 1999. FWC is responsible for conserving 

the state’s freshwater aquatic life, marine life, and wild animal life. Its mission is to 

manage aquatic life and wild animal life and their habitats to perpetuate a diversity of 

species with densities and distributions that provide sustained ecological, recreational, 

scientific, educational, aesthetic, and economic benefits. The commission has a formal 

commenting role in the regulatory process relating to listed endangered species 

protection in wetland areas. The Division of Law Enforcement provides protection and 

enforces laws relating to all wild animal and aquatic resources and boating safety on the 

state’s waters. 

University of Florida / Institute of Food & Agricultural Science (UF/IFAS) 

UF/IFAS is a statewide organization dedicated to teaching, research, and extension and 

serves the agricultural, human, and natural resource needs for the State of Florida. 

UF/IFAS is a partnership in food, agriculture, natural and renewable resource research, 

and education and is funded through federal, state, and local governments and 

industry. UF/IFAS has nearly 1,000 faculty located on the University of Florida campus 

and at extension offices in 67 counties, 21 research and education centers, and 4 

demonstration units. 

Florida Department of Community Affairs (FDCA) 

FDCA has five service areas which include Community Planning, Emergency 

Management, Coastal Management, Housing and Community Development, and the 

Florida Communities Trust. The Bureau of Local Planning in the Division of 

Community Planning reviews local government comprehensive plans and plan 

amendments for compliance with state law and provides technical assistance to local 

governments. It also reviews developments of regional impact and Florida quality 

developments in coordination with regional planning councils and local governments. 

The Bureau of State Planning in the Division of Community Planning is responsible for 
Governmental Jurisdiction 

St. Johns River Water Management District

49 

coordination and development of FDCA’s policy relating to Florida’s growth 

management statutes and rules. The Division of Emergency Management directs the 

state’s programs that plan for and respond to disasters, prepares a Comprehensive 

Emergency Management Plan and serves as the state’s liaison with federal and local 

agencies. 

Florida Department of Agriculture and Consumer Services (FDACS) 

FDACS is responsible for safeguarding the public and supporting Florida’s agricultural 

economy. FDACS performs all regulatory and inspection services relating to 

agriculture, with the exception of those functions which primarily protect the public 

health, and regulates the registration, labeling and inspection of pesticides, commercial 

fertilizer, gasolines and oils, and the licensing and regulation of pesticide applicators. 

The Office of Agricultural Water Policy provides support for the 63 soil and water 

conservation districts in the state. The Division of Forestry manages state forest lands 

and promotes the use of good silviculture practices on public and private lands. It is the 

lead fire control agency of the state and is responsible for authorizing prescribed burns 

as well as for suppressing wildfires. 

Florida Department of Health 

The Florida Department of Health responsibilities include permitting for public health 

functions of water supplies (primarily small to medium supplies), onsite sewage 

treatment and disposal, septic tank cleaning and waste disposal (in conjunction with 

FDEP), and solid waste control (secondary role). 

Florida Department of Transportation (FDOT) 

FDOT directs and coordinates roadway and bridge construction activities and related 

environmental studies, including corridor and impact mitigation planning. 

Public Service Commission 

The Public Service Commission is responsible for regulating the rates, services, and 

safety of several types of investor-owned utilities, including water and wastewater 

utilities. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

50 

REGIONAL

Water Management Districts 

Florida is divided into five water management districts, which are dedicated to the 

preservation and management of Florida’s water resources. Duties of the districts 

include issuing permits for various water use activities and/or activities that have the 

potential to adversely impact ground or surface water resources and adjacent lands; 

buying land to preserve or restore vital wetlands and water resources; conducting 

research about the quality and quantity of ground and surface water resources; 

mapping ground and surface water resources; and conducting outreach and public 

education programs. 

SJRWMD is responsible for managing ground and surface water supplies in all or part 

of 19 counties in northeast and east-central Florida. 

Regional Planning Councils (RPCs) 

RPCs are multipurpose regional entities in a position to plan for and coordinate 

intergovernmental solutions to growth-related problems or greater-than-local issues, 

provide technical assistance to local governments, and meet other needs of the 

communities in their regions. RPCs review amendments to local government 

comprehensive plans for impacts to regionally significant resources and 

extrajurisdictional impacts and provide technical assistance and other services to local 

governments relating to comprehensive planning. RPCs serve as a coordination and 

review function for developments of regional impact/Florida quality developments. 

The East Central Florida Regional Planning Council provides regional planning services 

to Brevard, Lake, Orange, Osceola, Seminole, and Volusia counties. 

Soil and Water Conservation Districts 

The 63 soil and water conservation districts located statewide are organized under 

Chapter 582, FS, as a governmental subdivision of the state. The appointed or elected 

volunteers serving on the governing boards coordinate public and private assistance to 

develop local solutions to natural resource concerns. The two local soil and water 

conservation districts located within the Lake Apopka Basin are those of Lake County 

and Orange County. 
Governmental Jurisdiction 

St. Johns River Water Management District

51 

Water Authorities 

The Lake County Water Authority, formerly known as the Ocklawaha Basin Recreation 

and Water Conservation and Control Authority, was created in 1953 by the Legislature to 

protect surface waters. It is actively involved in aquatic plant control, stormwater 

treatment, wetlands protection, providing recreational facilities, and land acquisition and 

management. 

LOCAL

County Governments 

• Lake County contains 14 municipalities, with Tavares as the county seat. 

 Board of County Commissioners 

 Environmental Management Division 

 Mosquito Control and Aquatic Plant Management 

 Department of Growth Management 

 Health Department 

 Department of Community Services 

 Department of Economic Development and Tourism 

 Department of Public Safety 

 Department of Public Works 

• Orange County contains 13 municipalities, with Orlando as the county seat. 

 Board of County Commissioners 

 Department of Community and Environmental Services 

 Department of Growth Management 

 Department of Health and Family Services 

 Director of Public Safety 

 Public Works Department 

 Utilities Department 

Municipal Governments 

• Lake County 

 Town of Montverde 

• Orange County 

 City of Apopka 

 City of Oakland 

 City of Winter Garden 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

52 
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

53 

PLANNING: ISSUES, GOALS, STRATEGIES, PROGRAMS, AND 

PROJECTS

DISTRICT PLANNING

SJRWMD has an integrated planning, budgeting and reporting system under which 

long-term plans guide short-term plans, budgets are linked to plans, progress is tracked 

using statewide water management and program-specific performance measures, and 

progress is reported on a regular basis. The District Water Management Plan (DWMP), 

SJRWMD’s comprehensive long-term plan, and other long-term plans, such as SWIM 

plans, provide direction for the Annual Work Plan and Budget (AWPB), fiscal plans, 

and other District planning efforts. The AWPB connects tasks listed for each District 

program with program budgets. 

The DWMP contains strategies for identified water resource issues to be implemented 

over the five-year period between DWMP updates. The strategies for the Lake Apopka 

SWIM program in the May 2000 DWMP, as updated for the June 2001 Florida Forever 

Work Plan, are as follows: 

• Adopt and achieve full implementation of a PLRG-based rule for reducing and 

allocating phosphorus loads in the Lake Apopka Basin. 

• Operate Phase I of the marsh flow-way and achieve removal efficiencies of at least 

30% of total phosphorus, 30% of total nitrogen, and 80% of total suspended solids. 

• Construct Phase II of the Lake Apopka Marsh Flow-Way. 

• Continue to harvest gizzard shad up to 900,000 pounds a year or until the annual 

stock is depleted. 

• Treat remaining former farm areas to bind sediment phosphorus. 

• Complete all necessary pesticide studies and remediation activities. 

• Continue lake littoral zone planting and management to encourage native and 

discourage exotic vegetation. 

• Complete and begin implementation of a restoration plan for the NSRA as approved 

by partners and stakeholders. 

• Complete infrastructure development as set out in the NSRA restoration plan. 

• Shallowly flood appropriate areas in the NSRA as soon as the necessary 

infrastructure is completed and oversight agency approval is received. 

• Restore 13,000 acres of wetlands in the NSRA, pending approval of the USDANRCS. 

• Attain a healthy diversity of wetland plant and animal communities. 

• Complete revisions to the SWIM Plan for Lake Apopka. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

54 

• Evaluate progress made in the lake ecosystem restoration. 

• Provide technical assistance and cost-share funding for implementation of the Lake 

Apopka Basin Planning Initiative Work Program, to be completed by fiscal year 

2000–2001. 

• Provide technical assistance to and coordinate SJRWMD restoration activities with 

local governments in the Lake Apopka Basin, developing and implementing smallarea plans to guide their future development. 

Tasks for the Lake Apopka SWIM program in the AWPB contribute to the 

implementation of these strategies, as well as the strategies identified in the SWIM Plan. 

Performance measures for the Lake Apopka SWIM program in the May 2000 DWMP 

and AWPB follow, along with baseline data and standards for the measures. 

Measure: Designated use determinations in the FDEP 305(b) report for Lake 

Apopka watersheds 

Baseline: Lake Apopka watershed not meeting and Apopka (Gourd Neck) Spring 

watershed partially meeting its designated use in 1998 

Standard: Both watersheds fully meeting their designated use 

Measure: Mean total phosphorus concentration in Lake Apopka 

Baseline: 0.218 mg/L from 1987 to 1995 

Standard: 0.055 mg/L 

LAKE APOPKA SWIM PLAN

A planning process for the restoration of Lake Apopka was initiated in 1985 under the 

Lake Apopka Restoration Act. The Lake Apopka Restoration Council (LARC) 

recommended specific goals for restoration of the lake, as follows: 

• Rooted native vegetation at 50% lake bottom coverage 

• Fish biomass in the littoral zone of 37 kg/ha (200 lbs/ac) 

• Sportfish biomass at 70% of total 

• Largemouth bass greater than 25 cm (9.8 in.) total length in littoral zone at six 

fish/ha (15 fish/ac) 

• Fishing success rate of .25 largemouth bass/hour of effort and 1.25 panfish/hour of 

effort 

• Macroinvertebrate Shannon-Weaver Diversity Index of 1.9 

• Total phosphorus and total nitrogen at specified concentrations (to be set) 

• Chlorophyll a at specified levels (to be set) 

• Specified Secchi disk depth (to be set) 
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

55 

The technical advisory committee to the LARC recommended the following values for 

the latter four specific goals: total phosphorus, 0.02 mg/L (20 ppb); total nitrogen, 0.50 

mg/L (50 ppb); chlorophyll a, 6.0 grams per liter (g/L) (6.0 ppb); Secchi disc depth, 1.3 

m (4.2 ft). To achieve these goals, the LARC recommended the following strategies as 

some of the most logical alternatives to pursue: 

• Conversion of muck farms to wetland systems 

• Lake level drawdown/increased water level fluctuation 

• Sediment recycling or dredging 

• Sediment phosphorus inactivation 

• Lake drawdown combined with dredging 

• Lake drawdown combined with phosphorus inactivation in non-drawdown areas 

• Microbial decomposition with sediment aeration 

• Microbial decomposition without sediment aeration 

• Lake drawdown combined with microbial decomposition of non-drawdown areas 

• Introduction of exotic fish and management of the food web 

• Littoral zone restoration 

• Growth and harvesting of water hyacinths 

• Alteration of the density of plankton-feeding fishes in the lake 

• No action taken after nutrient diversion 

Based on the LARC 1986 and 1987 reports and the Interim SWIM Plan (Battoe et al. 

1988), the 1989 SWIM Plan (Conrow et al. 1989) developed seven priority issues for 

Lake Apopka (Figure 16). These issues, which must be addressed in order to achieve the 

restoration of the lake and to help in protection of downstream water bodies, are as 

follows: 

• Agricultural discharges 

• Lack of fish and wildlife habitat 

• Poor water quality and flocculent sediments 

• Degradation of downstream lakes 

• Low recreational and aesthetic values 

• Nonpoint pollution sources 

• Future basin development 

The SWIM Plan establishes water body goals which reflect the broader goals of the 

SWIM Act as follows: 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

56 

ISSUES 

A. Agricultural discharges 

B. Lack of fish and wildlife habitat 

C. Poor water quality and flocculent sediments 

D. Degradation of downstream lakes 

E. Low recreational and aesthetic values 

F. Nonpoint pollution sources 

G. Future basin development 

PROGRAMS and PROJECTS

Diagnostic 

External Nutrient Budget

Internal Nutrient Budget 

Mathematical Modeling 

Phytoplankton-Nutrient Interactions 

Bathymetry 

Fishery 

Seismic Reflection Profiling

Hydrodynamic Survey 

Technical Support 

Implementation of Restoration and 

Management Techniques 

Restoration Monitoring and Analysis 

Overall Program Management

Figure 16. Overall Lake Apopka SWIM Plan

Feasibility 

Water Hyacinth Demonstration

Phosphorus Inactivation/Precipitation 

Sediment Recycling 

Microbial Decomposition 

Ichthyofaunal Reconstruction (I, II) 

Trophic Structure Manipulation (I, II, III)

Drawdown and Lake Level Fluctuation 

Socioeconomic Assessment and 

Methodology 

Planning 

District Water Management Plan 

Local Govt. Comp. Plan Review 

Land Management Plans 

Restoration 

Marsh Flow-Way Restoration 

Rough Fish Harvesting 

Wetland Restoration 

Littoral Zone Restoration

Land Acquisition 

Marsh Flow-Way Lands Acquisition 

North Shore Land Acquisition Regulatory 

Nonpoint Source Pollution Control 

Nutrient Loading Limits Adoption 

Public Information 

Public Awareness 

Local Government Information Project 
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

57 

Lake water restored to meet Class III water quality standards 

• Natural systems restored 

• Recreational and aesthetic values restored 

• A comprehensive management plan developed for maintenance of the water body 

and its environment 

The following sections present details on the seven priority issues for the restoration of 

Lake Apopka. The goals associated with each priority issue, the strategies that will be 

employed to attain the goal(s), and the programs and projects considered necessary for 

implementing the strategies are listed under each issue. Progress made towards 

achieving the goals is summarized for each priority issue, and detailed status 

summaries are available for each project (Detail of Projects section). 

An identification numbering system has been developed to facilitate tracking of 

individual projects. These codes are described in the Programs and Projects section , 

along with detailed explanations of Lake Apopka SWIM programs and projects. 

The restoration goals recommended by the LARC and the technical advisory committee 

are maintained as desirable results of the restoration program developed in the Lake 

Apopka SWIM Plan. The feasibility of attaining these specific goals cannot yet be 

determined. LARC goals dealing with habitat and sport fishery will be considered in 

the Littoral Zone Restoration Project (LA-2-304-M). Technical advisory committee goals 

dealing with nutrients, chlorophyll a, and Secchi depth will be considered in the setting 

of PLRGs (Nutrient Loading Limits Adoption, LA-3-403-M). Many of the studies 

recommended by the LARC were completed as SWIM projects. A bibliography and 

abstracts of many of these studies are included in Appendices G and H, respectively. 

A. Agricultural Discharges 

Issue Description. Agricultural discharges (Figure 17) have been the major source of 

external nutrient loading to Lake Apopka. Prior to implementation of consent orders, 

SJRWMD estimated that over one-third of the lake’s water volume was discharged 

annually to Lake Apopka and the Apopka-Beauclair Canal from the adjacent 

agricultural operations. These discharge waters were nutrient-laden and contributed 

approximately 85% of the phosphorus loading to Lake Apopka from 1989 to 1994. The 

discharge waters did not comply with water quality standards as in Chapter 62-302, 

F.A.C., and negatively affected the natural systems of the lake. 

Goal. Decrease agricultural nutrient loading to meet or exceed established PLRGs. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

58 

Figure 17. Agricultural discharges

Project Numbers

LA-1-101-D

LA-4-103-D

Diagnostic Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Monitor agricultural discharge

Acquire agricultural lands

Consider water treatment facility

Strategies

Measure nutrient load

Evaluate impact

Enforce regulations

Goal

Meet or exceed established pollutant load reduction goals

Issue

Agricultural discharges

Figure 17. Agricultural discharges

Project Numbers

LA-1-101-D

LA-4-103-D

Diagnostic Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Monitor agricultural discharge

Acquire agricultural lands

Consider water treatment facility

Strategies

Measure nutrient load

Evaluate impact

Enforce regulations

Goal

Meet or exceed established pollutant load reduction goals

Issue

Agricultural discharges
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

59 

Strategies

• Measure nutrient loading from agricultural discharges. 

• Evaluate the impact of agricultural nutrient loading. 

• Develop and adopt nutrient loading limits for the lake. 

• Pursue regulatory enforcement and consent order compliance. 

• Monitor agricultural discharges to assure compliance. 

• Reduce number of acres in agricultural production by acquiring land. 

• Investigate potential for matching grant program for agricultural waste treatment 

facility construction. 

Programs and Projects. The following programs and projects are considered necessary 

to implement designated strategies: 

1. Diagnostic Program 

Project LA-1-101-D (External Nutrient Budget Study) 

Project LA-4-103-D (Mathematical Modeling) 

2. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

3. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

4. Land Acquisition Program 

Project LA-3-701-S (Marsh Flow-Way Land Acquisition) 

Project LA-3-704-S (North Shore Land Acquisition) 

B. Lack of Fish and Wildlife Habitat 

Issue Description. There has been a substantial loss of fish and wildlife habitat in Lake 

Apopka (Figure 18). The once-prolific beds of submerged vegetation that provided food 

and cover for game fish have disappeared due to increased turbidity from algal blooms 

and resuspended flocculent sediments. Wildlife habitat provided by the original 

palustrine wetlands of the lake has been destroyed by encroachment of muck farms, 

and flocculent organic sediments have buried the original, firmer lake bottom. Cultural 

eutrophication of the water body has resulted in a shift of primary productivity from 

large plants to algae. This loss of habitat has resulted in a drastic decline in the 

recreational fishery of Lake Apopka. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

60 

Figure 18. Lack of fish and wildlife habitat

Project Numbers

LA-4-107-D

LA-4-109-D

Diagnostic Program

Project Numbers

LA-4-206-F LA-4-208-F

LA-4-207-F

Feasibility Program

Project Numbers

LA-3-301-M LA-3-302-M

LA-3-303-M LA-2-304-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Project Numbers

LA-6-501-M

LA-6-503-M

LA-6-502-S

Planning Program

Goals

Restore wetlands

Protect remaining habitat

Restore littoral zone and submerged rooted vegetation

Issue

Lack of fish and wildlife habitat

Acquire agricultural lands

Restore littoral zone

Adopt nutrient loading limits

Strategies

Participate in local government comprehensive planning

Test methods to improve habitat

Figure 18. Lack of fish and wildlife habitat

Project Numbers

LA-4-107-D

LA-4-109-D

Diagnostic Program

Project Numbers

LA-4-206-F LA-4-208-F

LA-4-207-F

Feasibility Program

Project Numbers

LA-3-301-M LA-3-302-M

LA-3-303-M LA-2-304-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Project Numbers

LA-6-501-M

LA-6-503-M

LA-6-502-S

Planning Program

Goals

Restore wetlands

Protect remaining habitat

Restore littoral zone and submerged rooted vegetation

Issue

Lack of fish and wildlife habitat

Acquire agricultural lands

Restore littoral zone

Adopt nutrient loading limits

Strategies

Participate in local government comprehensive planning

Test methods to improve habitat

Acquire agricultural lands

Restore littoral zone

Adopt nutrient loading limits

Strategies

Participate in local government comprehensive planning

Test methods to improve habitat

Acquire agricultural lands

Restore littoral zone

Adopt nutrient loading limits

Strategies

Participate in local government comprehensive planning

Test methods to improve habitat
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

61 

Goals

• Protect remaining fisheries/wildlife habitat 

• Restore marshes adjacent to the lake 

• Restore and expand lake littoral zone and emergent vegetation along the shore 

• Improve lake bottom habitat and restore submerged rooted vegetation 

Strategies

• Purchase available lands appropriate for habitat restoration. 

• Investigate and test methods to improve fisheries habitat by increasing water clarity 

and consolidating sediments. 

• Identify and map existing fisheries/wildlife habitat and investigate restoration and 

expansion of littoral zone. 

• Develop and adopt special nutrient loading limits for the lake. 

• Assist in the development and implementation of stronger local ordinances. 

Programs and Projects. The following programs and projects are considered necessary 

for strategy implementation: 

1. Diagnostic Program 

Project LA-4-107-D (Fishery) 

Project LA-4-109-D (Hydrodynamic Survey) 

2. Feasibility Program 

Project LA-4-206-F (Ichthyofaunal Reconstruction I, II) 

Project LA-4-207-F (Trophic Structure Manipulation I, II, III) 

Project LA-4-208-F (Drawdown and Lake Level Fluctuation) 

3. Restoration Program 

Project LA-3-301-M (Marsh Flow-Way Restoration) 

Project LA-3-302-M (Rough Fish Harvesting) 

Project LA-2-304-M (Littoral Zone Restoration) 

Project LA-3-303-M (Wetland Restoration) 

4. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

5. Planning Program 

Project LA-6-501-M (District Water Management Plan) 

Project LA-6-502-S (Local Government Comprehensive Plan Review) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

62 

Project LA-6-503-M (Land Management Plans) 

6. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

7. Land Acquisition Program 

Project LA-3-701-S (Marsh Flow-Way Land Acquisition) 

Project LA-3-704-S (North Shore Land Acquisition) 

C. Poor Water Quality and Flocculent Sediments 

Issue Description. Lake Apopka was once crystal clear with a firm bottom. Water 

quality in the lake has become severely degraded, and the bottom is now covered with 

flocculent organic sediments several feet thick (Schelske 1997). High nutrient loading, 

primarily from agricultural sources, has resulted in high nitrogen and phosphorus 

levels, excessive algal production, and reduced water clarity in the lake. The lack of 

sufficient light reaching the lake’s bottom limits submerged aquatic vegetation growth. 

The excessive algal production has caused accelerated accretion of flocculent sediments 

over most of the lake bottom (Figure 19). 

Goals

• Develop and implement a cost-effective and scientifically sound restoration program 

to improve water quality and consolidate sediments. 

• Restore and manage wetlands for improvement and maintenance of water quality. 

• Undertake appropriate basin management to promote improved water quality and 

long-term management to prevent water quality degradation. 

Strategies

• Develop a clear understanding of water quality problems and associated ecological 

impacts. 

• Determine external and internal nutrient inputs. 

• Continue diagnostic studies to fill critical data deficiencies. 

• Continue feasibility studies to evaluate potential restoration techniques. 

• Plan and implement nutrient loading limits for the watershed. 

• Establish a long-range comprehensive management plan for the basin. 

• Participate in local and regional planning efforts. 

• Implement cost-effective restoration projects. 
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

63 

Figure 19. Poor water quality and flocculent sediments

Project Numbers

LA-1-101-D LA-1-102-D

LA-4-103-D LA-4-104-D

LA-4-106-D LA-1-108-D

Diagnostic Program

Project Numbers

LA-3-301-M

LA-3-302-M

Restoration Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Project Numbers

LA-4-201-F LA-4-202-F

LA-4-204-F LA-4-205-F

LA-4-206-F LA-4-207-F LA-2-208-F

Feasibility Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Implement nutrient loading limits/cost-effective restoration

Establish management plan

Promote local government comprehensive plans

Strategies

Determine nutrient inputs

Perform diagnostic/feasibility studies

Define water quality problems and ecological roles

Goals

Restore water quality/sediment

Restore and manage wetlands

Manage basin appropriately

Issue

Poor water quality and flocculent sediments

LA-3-303-M

LA-3-304-M

LA-6-503-M

Figure 19. Poor water quality and flocculent sediments

Project Numbers

LA-1-101-D LA-1-102-D

LA-4-103-D LA-4-104-D

LA-4-106-D LA-1-108-D

Diagnostic Program

Project Numbers

LA-3-301-M

LA-3-302-M

Restoration Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Project Numbers

LA-4-201-F LA-4-202-F

LA-4-204-F LA-4-205-F

LA-4-206-F LA-4-207-F LA-2-208-F

Feasibility Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Implement nutrient loading limits/cost-effective restoration

Establish management plan

Promote local government comprehensive plans

Strategies

Determine nutrient inputs

Perform diagnostic/feasibility studies

Define water quality problems and ecological roles

Goals

Restore water quality/sediment

Restore and manage wetlands

Manage basin appropriately

Issue

Poor water quality and flocculent sediments

LA-3-303-M

LA-3-304-M

LA-6-503-M
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

64 

Programs and Projects. The following programs and projects are considered necessary 

to implement the primary strategies: 

1. Diagnostic Program 

Project LA-1-101-D (External Nutrient Budget) 

Project LA-1-102-D (Internal Nutrient Budget) 

Project LA-4-103-D (Mathematical Modeling) 

Project LA-4-104-D (Phytoplankton-Nutrient Interactions) 

Project LA-4-106-D (Bathymetry) 

Project LA-1-108-D (Seismic Reflection Profiling) 

2. Feasibility Program 

Project LA-4-201-F (Water Hyacinth Demonstration) 

Project LA-4-202-F (Phosphorus Inactivation/Precipitation) 

Project LA-4-204-F (Sediment Recycling) 

Project LA-4-205-F (Microbial Decomposition) 

Project LA-4-206-F (Ichthyofaunal Reconstruction I, II) 

Project LA-4-207-F (Trophic Structure Manipulation I, II, III) 

Project LA-4-208-F (Drawdown and Lake Level Fluctuation) 

3. Restoration Program 

Project LA-3-301-M (Marsh Flow-Way Restoration) 

Project LA-3-302-M (Rough Fish Harvesting) 

Project LA-3-303-M (Wetland Restoration) 

Project LA-3-304-M (Littoral Zone Restoration) 

4. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

5. Planning Program 

Project LA-6-501-M (District Water Management Plan) 

Project LA-6-502-S (Local Government Comprehensive Plan Review) 

Project LA-6-503-M (Land Management Plans) 

6. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

7. Land Acquisition Program 

Project LA-3-701-S (Marsh Flow-Way Land Acquisition) 

Project LA-3-704-S (North Shore Land Acquisition) 
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

65 

D. Degradation of Downstream Lakes 

Issue Description. Lake Apopka is the headwater lake and primary source of surface 

water for the Harris Chain of Lakes (Lakes Beauclair, Dora, Eustis, Harris, Griffin, and 

Yale) and the Upper Ocklawaha River. Nutrient-laden water from Lake Apopka 

contributes significantly to the eutrophication of the remaining lakes in the chain. 

Goal. Reduce or eliminate the degradation of downstream lakes from Lake Apopka 

discharge water (Figure 20). 

Strategies. Reduction in nutrient and sediment transport from the Lake Apopka Basin 

requires (1) a reduction in external nutrient loading, especially from farms along the 

Apopka-Beauclair Canal, (2) improvement in water quality in Lake Apopka, and (3) 

discharge of water from Lake Apopka through the marsh flow-way instead of directly 

from the lake. 

• Purchase available agricultural lands. 

• Enforce existing water quality regulations and consent order compliance. 

• Confine downstream discharges to waters filtered through the marsh flow-way 

system. 

• Monitor downstream discharge at the Apopka-Beauclair Canal. 

• Develop and adopt nutrient loading limits for the watershed. 

• Evaluate potential for matching grants for agricultural wastewater treatment 

facilities construction. 

Programs and Projects. The following programs and projects are necessary to reduce 

downstream discharge of degraded water: 

1. Diagnostic Program 

Project LA-1-101-D (External Nutrient Budget) 

Project LA-4-103-D (Mathematical Modeling) 

2. Restoration Program 

Project LA-3-301-M (Marsh Flow-Way Restoration) 

3. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

66 

Figure 20. Degradation of downstream lakes

Project Numbers

LA-1-101-D

LA-4-103-D

Diagnostic Program

Project Number

LA-3-301-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-704-S

Land Acquisition Program

Strategies

Monitor canal discharge

Adopt nutrient loading limits

Purchase lands

Enforce regulations/consent orders

Filter discharge water through marsh

Goal

Reduce or eliminate downstream degradation from Lake Apopka

discharge waters

Issue

Degradation of downstream lakes

Figure 20. Degradation of downstream lakes

Project Numbers

LA-1-101-D

LA-4-103-D

Diagnostic Program

Project Number

LA-3-301-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-704-S

Land Acquisition Program

Strategies

Monitor canal discharge

Adopt nutrient loading limits

Purchase lands

Enforce regulations/consent orders

Filter discharge water through marsh

Goal

Reduce or eliminate downstream degradation from Lake Apopka

discharge waters

Issue

Degradation of downstream lakes
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

67 

4. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

5. Land Acquisition Program 

Project LA-3-701-S (Marsh Flow-Way Land Acquisition) 

Project LA-3-704-S (North Shore Land Acquisition) 

E. Low Recreational and Aesthetic Value 

Issue Description. Lake Apopka was once a lake with clear waters, a stable habitat for 

fish propagation, and a productive sports fishery. The lake environment also provided 

excellent potential for water contact recreation and wildlife observation. Due to water 

quality degradation and loss of habitat, the lake environment is now one of unsightly 

blue-green algal blooms, soft bottom sediments, and very limited wetland habitat. 

These changes have resulted in lost recreational opportunities in and around Lake 

Apopka (Figure 21). 

Goals

• Attain water quality suitable for water contact recreation. 

• Improve multi-use recreational opportunities. 

• Restore abundant and diverse populations of native plants, wildlife, and fish to the 

basin. 

Strategies

• Acquire available agricultural lands. 

• Test feasibility of littoral zone restoration and expansion. 

• Investigate methods of water quality restoration and sediment consolidation. 

• Establish marsh flow-way. 

• Develop and adopt additional regulatory criteria for the lake basin. 

• Establish a long-range comprehensive management plan for the basin. 

• Develop land management plans for acquired properties. 

• Implement rough fish harvest. 

• Participate in local government comprehensive planning. 

Programs and Projects. The following programs and projects are considered necessary 

for strategy implementation: 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

68 

Figure 21. Low recreational and aesthetic value

Project Numbers

LA-2-208-F

LA-2-209-F

Feasibility Program

Project Numbers

LA-2-304-M LA-3-301-M

LA-3-302-M LA-3-303-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Develop comprehensive management plan and regulatory criteria

Establish marsh flow-way

Implement rough fish harvest

Strategies Acquire lands

Test feasibility of restoration

Investigate methods and adopt management plans

Goals

Make water safe for contact recreation

Improve multi-use recreational opportunities

Restore populations of plants, wildlife, and fish to basin

Issue

Low recreational and aesthetic value

LA-6-503-M

Figure 21. Low recreational and aesthetic value

Project Numbers

LA-2-208-F

LA-2-209-F

Feasibility Program

Project Numbers

LA-2-304-M LA-3-301-M

LA-3-302-M LA-3-303-M

Restoration Program

Project Number

LA-3-403-M

Regulatory Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Numbers

LA-5-602-S

LA-5-603-S

Public Info Program

Project Numbers

LA-3-701-S

LA-3-705-S

Land Acquisition Program

Develop comprehensive management plan and regulatory criteria

Establish marsh flow-way

Implement rough fish harvest

Strategies Acquire lands

Test feasibility of restoration

Investigate methods and adopt management plans

Goals

Make water safe for contact recreation

Improve multi-use recreational opportunities

Restore populations of plants, wildlife, and fish to basin

Issue

Low recreational and aesthetic value

LA-6-503-M
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

69 

1. Feasibility Program 

Project LA-4-208-F (Drawdown and Lake Level Fluctuation) 

Project LA-4-209-F (Socioeconomic Assessment and Methodology) 

2. Restoration Program 

Project LA-3-301-M (Marsh Flow-Way Restoration) 

Project LA-3-302-M (Rough Fish Harvesting) 

Project LA-3-303-M (Wetland Restoration) 

Project LA-2-304-M (Littoral Zone Restoration) 

3. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

4. Planning Program 

Project LA-6-501-M (District Water Management Plan) 

Project LA-6-502-S (Local Government Comprehensive Plan Review) 

Project LA-6-503-M (Land Management Plans) 

5. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

6. Land Acquisition Program 

Project LA-3-701-S (Marsh Flow-Way Land Acquisition) 

Project LA-3-704-S (North Shore Land Acquisition) 

F. Nonpoint Pollution Sources 

Issue Description. The degree to which nonpoint sources other than agriculture 

contribute to problems in Lake Apopka was unclear during the formulation of the 

SWIM Plan. High nitrogen and phosphorus levels, excessive algal production, and 

reduced water clarity in the lake necessitated an evaluation of the relative importance of 

all nonpoint sources of pollution (Figure 22). 

Goal. Evaluate and eliminate significant nonpoint sources of pollution to Lake Apopka. 

Strategies

• Assess external sources of nutrients and internal recycling. 

• Assess the extent of urban runoff around the lake. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

70 

Strategies

Participate in local government comprehensive planning

Assess urban runoff

Develop enforcement contracts

Adopt nutrient loading limits

Assess external sources of nutrients and internal recycling

Determine failed septic systems

LA-1-101-D

LA-1-102-D

LA-4-103-D

LA-3-402-M

LA-3-403-M

LA-5-602-S

LA-5-603-S

Figure 22. Nonpoint pollution sources

Project Numbers

Diagnostic Program

Project Numbers

Regulatory Program

Project Numbers

Public Info Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Goal

Evaluate and eliminate nonpoint sources

Issue

Nonpoint pollution sources

Strategies

Participate in local government comprehensive planning

Assess urban runoff

Develop enforcement contracts

Adopt nutrient loading limits

Assess external sources of nutrients and internal recycling

Determine failed septic systems

LA-1-101-D

LA-1-102-D

LA-4-103-D

LA-3-402-M

LA-3-403-M

LA-5-602-S

LA-5-603-S

Figure 22. Nonpoint pollution sources

Project Numbers

Diagnostic Program

Project Numbers

Regulatory Program

Project Numbers

Public Info Program

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Goal

Evaluate and eliminate nonpoint sources

Issue

Nonpoint pollution sources
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

71 

• Determine the extent of failed septic systems around the lake. 

• Participate in local government comprehensive planning and assist in the 

development and implementation of stronger local ordinances. 

• Assess potential for enforcement contracts with Lake and Orange counties. 

• Adopt nutrient loading limits. 

Programs and Projects. The following programs and projects are considered necessary 

to implement designated strategies: 

1. Diagnostic Program 

Project LA-1-101-D (External Nutrient Budget) 

Project LA-1-102-D (Internal Nutrient Budget) 

Project LA-4-103-D (Mathematical Modeling) 

2. Regulatory Program 

Project LA-3-402-M (Nonpoint Source Pollution Control) 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

3. Planning Program 

Project LA-6-501-M (District Water Management Plan) 

Project LA-6-502-S (Local Government Comprehensive Plan Review) 

4. Public Information Program 

Project LA-5-602-S (Public Awareness) 

Project LA-5-603-S (Local Government Information Project) 

G. Future Basin Development 

Issue Description. Simultaneously with the completion of the projects that have 

addressed the preceding six issues, it will be necessary to support comprehensive basin 

planning to ensure maintenance of restored conditions in Lake Apopka. Proper 

protection and restoration of the lake’s resources require coordination among the 

federal, state, regional, and local agencies that have planning, regulatory, or 

management authority in the basin. The SWIM Act partially fulfills this requirement by 

directing SJRWMD, with the participation of other governmental agencies, to develop 

and implement an interagency management plan (Figure 23). 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

72 

Figure 23. Future basin development

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Numbers

LA-3-403-M

LA-3-402-M

Regulatory Program

Strategies

Adopt nutrient loading limits

Develop a comprehensive District water management plan

Assist local governments in comprehensive planning

Goals

Develop appropriately

Enforce compliance

Standardize agency management

Issue

Future basin development

Figure 23. Future basin development

Project Numbers

LA-6-501-M

LA-6-502-S

Planning Program

Project Numbers

LA-3-403-M

LA-3-402-M

Regulatory Program

Strategies

Adopt nutrient loading limits

Develop a comprehensive District water management plan

Assist local governments in comprehensive planning

Goals

Develop appropriately

Enforce compliance

Standardize agency management

Issue

Future basin development
Planning: Issues, Goals, Strategies, Programs, and Projects 

St. Johns River Water Management District

73 

Goals

• Develop plan consistent with environmental protection of the lake. 

• Enforce effective rules and permit compliance. 

• Standardize resource management among regulatory agencies. 

Strategies

• Establish nutrient loading limits for the water body. 

• Evaluate the implementation of the District Water Management Plan annually. 

• Participate in local government comprehensive planning and assist in the 

development and implementation of stronger local ordinances. 

• Establish a long-range comprehensive management plan for the basin. 

Programs and Projects. The following programs and projects are considered necessary 

to implement designated strategies: 

1. Regulatory Program 

Project LA-3-403-M (Nutrient Loading Limits Adoption) 

Project LA-3-402-M (Nonpoint Source Pollution Control) 

2. Planning Program 

Project LA-6-501-M (District Water Management Plan) 

Project LA-6-502-S (Local Government Comprehensive Plan Review) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District 

74 
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

75 

PROGRESS OF THE LAKE APOPKA RESTORATION PROGRAM

OVERVIEW

The Lake Apopka restoration effort is a holistic water resources, economic, and 

recreational restoration approach designed to return the water body to a condition that 

meets Class III water quality standards. In the years since the 1985 Lake Apopka 

Restoration Act, SJRWMD has implemented a comprehensive array of SWIM projects to 

address the seven priority issues described in the previous section. Following thorough 

scientific study, a four-part restoration program was developed: 

• Reduce phosphorus loading from external sources, primarily resulting from 

agricultural operations, through regulation and land acquisition. 

• Remove phosphorus and flocculent sediments to accelerate recovery of the lake by 

wetland filtration (marsh flow-way) and by mass removal of rough fish. 

• Improve food-web structure by removal of gizzard shad to benefit production of 

game fish and improve water quality. 

• Restore lake habitat through littoral zone planting and increased fluctuation in lake 

levels. 

REDUCTION IN NUTRIENT LOADING

Actions are under way that will decrease phosphorus loading to the lake through 

regulatory, land acquisition, and nutrient reduction activities. 

Regulatory 

A major regulatory action in support of the Lake Apopka restoration was to restrict 

phosphorus loading from the muck farms formerly located on the northern edge of the 

lake. Two major farming entities operated on the former marshes: A. Duda and Sons 

(Duda), with approximately 2,633 ha (6,500 ac) of muck farm fields on both sides of the 

Apopka-Beauclair Canal, and the Zellwood Drainage and Water Control District 

(ZDWCD), controlling discharges from about one dozen farms on 3,524 ha (8,700 ac) 

east of the Duda Jem Farm holdings. ZDWCD contained two large farming areas, Unit I 

to the north of the McDonald Canal and Unit II to the south of the McDonald Canal. 

On June 1, 1988, SJRWMD began regulating agricultural discharges under authority 

transferred by FDEP. That same month, SJRWMD and Duda entered into a consent 

order designed to reduce discharges and protect water quality according to a fixed time 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

76 

schedule (Appendix I). The consent order required Duda to construct a reservoir for 

Jem Farm and acknowledged that the farms west of the Apopka-Beauclair Canal would 

be sold to SJRWMD. In May 1989, SJRWMD and ZDWCD signed a consent order 

(Appendix I). In the case of ZDWCD, a challenge brought by a local resident delayed 

implementation of the consent order until 1991. Later modifications of the consent order 

between ZDWCD and SJRWMD outlined a provision for construction of an alum 

injection system to reduce orthophosphate loads from ZDWCD, beginning in 1995. 

In 1994, SJRWMD published a proposed Works of the District rule for Lake Apopka as 

the means of meeting the PLRG set for the lake. ZDWCD challenged the rule in a State 

of Florida Administrative Hearing. In August 1995, the Final Order of the Hearing 

Officer stated that SJRWMD did not have the regulatory authority to implement 

narrative water quality standards through nutrient limitations for the lake, and found 

that certain components of the technical basis of the rule were flawed. 

The 1996 Legislature gave SJRWMD the legal authority to set a phosphorus discharge 

limitation for Lake Apopka (Appendix A). The legislation provided for the 

development of a cost-shared detention pond system in the event that the buyout 

program was not successful. It also set a phosphorus criterion for the lake of 55 ppb in 

the event that SJRWMD did not adopt a rule by January 1997. 

SJRWMD responded with revisions to Chapter 40C-4, F.A.C., and the Applicant’s 

Handbook: Management and Storage of Surface Waters (Appendix I) effective August 1996. 

This rule “establishes a phosphorus criterion for Lake Apopka.” It will be used to 

establish discharge limitations for all regulated activities within the Lake Apopka 

drainage basin that are permitted to discharge, directly or indirectly, into Lake Apopka, 

the Lake Level Canal, and the McDonald Canal. 

PLRGs will be a primary tool to control the level of nutrient inputs to Lake Apopka 

from all sources. These goals will serve as the basis for the EPA-mandated TMDL 

process, required for all impaired water bodies and administered through FDEP. Public 

workshops to discuss phosphorus discharge limits were conducted during 1997, 2000, 

2001, and 2002. A notice of development of proposed rules was published in the Florida 

Administrative Weekly on December 29, 2000 (FAW 2001). Based on further discussions 

and a consultant’s review of the existing stormwater treatment criteria, SJRWMD staff 

incorporated several revisions to the proposed rule. The proposed rule was approved 

by the Governing Board in 2002 and was published in the Florida Administrative Weekly

on April 19, 2002. Following concern by the public over the implementation cost of the 

rule, SJRWMD considered less costly alternatives that would still meet the statutory 

objectives of the proposed rule. The final rule adoption hearing was held in December 

2002. The rule became effective in March 2003. For activities SJRWMD regulates, the 
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

77 

rule will limit the loading of phosphorus, which must not increase over 

predevelopment rates. SJRWMD and FDEP will share implementation responsibilities. 

Land Acquisition 

Nutrient loading to Lake Apopka was decreased by SJRWMD’s purchase of all muck 

farms west of the Apopka-Beauclair Canal (2,362 ha or 5,833 acres). A portion of this 

land is being converted to the Marsh Flow-Way Project, which will remove particulate 

phosphorus from lake water. Lease-back agreements (which provided for orderly 

termination of farming activities) ended in August 1993 for Hooper Farms and 

Duda/Whittle. Similar agreements with Wilkinson-Cooper and C.C. Ranch ended in 

May 1994. Agricultural discharges from this area were primarily to the ApopkaBeauclair Canal and contributed to downstream loading. 

The 1996 Legislature determined that it was in the public interest for SJRWMD to 

pursue buyout of the farms east of the Apopka-Beauclair Canal as the long-term 

solution to the nutrient loading problem and provided $20 million toward farm 

acquisition. In addition, SJRWMD received $26 million from the USDA WRP. With the 

federal and state funding available, SJRWMD purchased the 1,285 ha (3,173 ac) Duda 

Lake Jem farm in April 1997. A technical restoration plan is being developed with the 

assistance of NRCS, which oversees the reserve program. 

During the 1997 legislative year, the state appropriated an additional $45 million for 

purchasing additional agricultural lands within the NSRA (Appendix A). Under 

Chapter 99-226, Laws of Florida, the Legislature authorized Specific Appropriation 1205 

to release $11 million for purchase of farmlands from the Water Management Lands 

Trust Fund during the 1999–2000 fiscal year. 

In August 1999, the final farmlands were purchased within ZDWCD. Through the end 

of 2000, a total of 7,972 ha (19,684 ac) had been approved by the Governing Board for 

purchase. Bringing the land into public ownership completes SJRWMD’s acquisition of 

Lake Apopka muck farms, with acquisition of small non-farming areas still pending 

(Figure 24). ZDWCD was dissolved in February 2000 as directed by 1999 state 

legislation. Water management responsibilities within ZDWCD were transferred to 

SJRWMD. 

All of the SJRWMD-acquired muck lands within the NSRA will eventually be restored 

to wetland and aquatic habitat. Restoration work will include modifications to the 

extensive network of drainage, pump, and levee systems; planting; and monitoring the 

progress of habitat development. Partial funding for initial restoration work is being 

provided by NRCS. 

Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

79 

Nutrient Reduction Activities 

In 1991, the Lake Apopka Hydrologic Unit Area Project was initiated jointly by the 

IFAS/Florida Cooperative Extension Service, NRCS, and the Consolidated Farm Service 

Agency. SJRWMD cooperated with this program, which provided technical and 

financial assistance to the 19 vegetable and sod growers to implement best management 

practices (BMPs), which reduced discharges into Lake Apopka and limited nutrient 

loading. For example, approximately 124,000 kg (273,000 pounds) of phosphorus 

fertilizer were applied to vegetables in the Lake Apopka Basin in 1991 (Crnko et al. 

1993). After emphasizing the use of calibrated soil testing for nutrient management 

through field trials, the amount of phosphorus fertilizer applied to farms in the Lake 

Apopka Basin was reduced 55% by 1993 (Crnko et al. 1993). During the same period, 14 

internal pumps, 164 water control structures, and 3 floating staff gauges were installed to 

promote water recycling and reduce discharges (Neal et al. 1994). 

Following purchase of the farms, SJRWMD developed a plan to further reduce 

phosphorus loading to meet discharge targets. Because the initial phosphorus release 

from reflooding the purchased farms on the north shore of Lake Apopka could be 

substantial, a soil amendment is being added to the soil surface to bind phosphorus 

with a single application. Soil treatment will reduce the time until the farms can be 

reconnected to the lake or until other final restoration steps are taken. Approximately 

800 ha (1,968 ac) of Jem Farms was treated in spring 1999, and Phase I of the marsh 

flow-way was treated as part of final construction. ZDWCD will be treated when 

studies of pesticide residues are completed. 

The soil amendment selected for use within the NSRA and the marsh flow-way is alum 

residual, a by-product of the drinking water treatment process. Surface water, in this 

case from Lake Washington in Brevard County, contains suspended materials such as 

sand, microscopic organisms, clay, and organic particles that cause color, taste, odor, 

and turbidity. Aluminum sulfate, or alum, is used to coagulate these particles so that 

they may be separated out. Other ingredients that are added during the process include 

granulated activated carbon and quick lime. Polymers are used to dewater the material. 

The residual was thoroughly tested for safety and effectiveness. Nationally, this 

material is becoming popular as a phosphorus pollution abatement tool and also is used 

worldwide as a soil additive (Hoge 2001). 

Reductions in Discharge and Nutrient Loading 

An additional methodology implemented to reduce phosphorus loadings to Lake 

Apopka is to treat pumped discharges from ZDWCD Unit I and Unit II. When 

SJRWMD acquired the ZDWCD properties, ZDWCD had already implemented a liquid 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

80 

alum treatment system in Unit II, but discharges from Unit I were untreated. In 

September 2001 it became necessary to discharge water from Unit I, so SJRWMD 

implemented a second liquid alum treatment system. To improve water treatment and 

water control efficiency, SJRWMD has contracted with a consultant to redesign both 

alum injection systems. The redesign is expected to be completed and implemented by 

mid-2003. 

Since 1989, there has been a significant decrease in the average annual muck farm total 

phosphorus (TP) loading to the lake (Figure 25) (Stites et al. 2001). Farm phosphorus 

discharges decreased due to altered water management practices, purchase of farm 

properties east of the Apopka-Beauclair Canal, and low rainfall in 1993 (Figure 26). 

0

20

40

60

80

100

120

metric tons

1989 1990 1991 1992 1993 1994 1995 1996

Figure 25. Lake Apopka Basin muck farm discharge of total phosphorus, 1989–96 

Water Quality Improvements 

In 1995, the TP concentration began to fluctuate around a new, lower level (Figure 27). 

Chlorophyll concentrations also declined in mid-1995 and have continued on a 

downward trajectory (Figure 28). In fact, the January 2000 value was the lowest 

monthly average measured in a decade of SJRWMD monitoring. Secchi depth, a 

measure of water clarity, increased by approximately 30% over the same period of time, 

with a significant increasing trend (Figure 29). These changes occurred during a period 

when average wind speeds measured at Lake Apopka were constant. Whether 

chlorophyll and Secchi depth have reached equilibrium with the new, lower average TP 
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

81 

0

2000

4000

6000

8000

10000

12000

14000

Volume (Ha-M)

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Figure 26. Lake Apopka Basin muck farm volumetric discharge, 1989–98 

Figure 27. Lake Apopka mean monthly total phosphorus, January 1987–March 2002 

0.145

0.205

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

TP-T (mg/l)

F
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

82 

Figure 28. Lake Apopka mean monthly chlorophyll a, October 1998–March 2002 

Figure 29. Lake Apopka mean monthly Secchi depth, January 1987–March 2002

64.58

92.47

0

50

100

150

200

250

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

CHLA (mg/m3)

0.295

0.230

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

SECCHI (m)
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

83 

concentration or if chlorophyll and Secchi depth will improve further without 

additional P loading reductions is unknown. With the first phase of the Lake Apopka 

Marsh Flow-Way scheduled to begin filtering the lake in the near future and the 

restoration of the acquired farmlands under way, even more dramatic improvements in 

water quality and clarity are anticipated within Lake Apopka in the coming years. 

REMOVAL OF PHOSPHORUS AND FLOCCULENT SEDIMENTS

Due to the sedimentary store of available phosphorus and the moderate hydraulic 

detention time in Lake Apopka (2.5 years), decreased nutrient loading to the lake will 

need to be augmented by aggressive phosphorus removal techniques to hasten the 

recovery of the lake. 

Marsh Flow-Way Project 

The Lake Apopka Marsh Flow-Way, a created wetland located west of the ApopkaBeauclair Canal, will remove phosphorus from lake water and permanently bury it in 

marsh sediments. Algae, resuspended sediments, and particle-bound nutrients will be 

removed from lake water as it flows through 13 independent marsh cells and returns to 

the lake (Figure 30). A portion of the treated water will also entirely replace the poorquality water now flowing through the Apopka-Beauclair Canal to the downstream 

lakes, thus improving their quality as well. Over the long term, about 10% of flow 

through the wetland will be discharged downstream and 90% will re-circulate to Lake 

Apopka. The full project is expected, given current water quality conditions, to remove 

30 metric tons of phosphorus annually from Lake Apopka (Lowe et al. 1989). The three 

long-term goals for the full-scale Marsh Flow-Way Project are to 

• Establish and maintain a hydrologic regime and vegetation that will maximize 

phosphorus removal in terms of both power (mass P removed/unit time) and capacity 

(mass P removed over project life) 

• Create a broad and persistent biological connection with the lake 

• Establish and maintain a diversity of habitats to support aquatic and wetland wildlife 

(Lowe et al. 1992) 

Until water quality conditions in the lake are sufficiently improved to warrant a change 

of focus, the marsh flow-way will be operated to meet the first of the three goals. 

The first step of the Marsh Flow-Way Project was the design, construction, and 

operation of a 223-ha (550-ac) demonstration-scale constructed wetland. This pilot 

project provided necessary experience and data for the design and construction of 
A

B1 B2

C1 C2

Phase I

(constructed)

Demonstration

project

Lake 

Apopka

Inlet channel

D1 D2

E1 E2

F1

G1

F2

G2

H

Phase II

(future)

Phase III

(future)

 Apopka− Beauclair

Lock and Dam



Apopka − Beauclair Canal

Clay

Island



Figure 30. Lake Apopka Marsh Flow−Way conceptual design 





Flow direction

Pumping station

Lock and dam

Existing levee

Planned levee

Legend

Conveyance canal

Dashed − planned canal

Solid − existing canal

0 1 0.5 Miles
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

85 

Phase I. Physical design, flow regimes, management tools, and operational costs for this 

type of wetland treatment system were evaluated in the seven-year effort. Experimental 

planting of emergent wetland plant species in three 2-ha (5-ac) plots were used to assess 

possible benefits of planting the system compared to the natural revegetation process 

allowed in the rest of the wetland. 

Lessons learned included the following (Coveney 1995): 

• Hydraulic functioning is key to effective nutrient control. 

• Multiple parallel cells are preferable to a single large treatment area. 

• Large-scale channelization must be avoided to maximize the hydraulic time 

distribution. 

• Drawdown was a necessary and effective technique to consolidate newly deposited 

sediment. 

The demonstration wetland was capable of removal of total suspended solids and total 

phosphorus at or above target efficiencies of 85% and 30%, respectively (Coveney, 

Lowe, and Battoe 2001). Several design features, such as multiple inlet and outlet 

locations and the creation of regularly spaced ditches perpendicular to flow, were 

applied in the design of Phase I to minimize channelization. 

Construction of Phase I of the full project began in December 1997. Funding for Phase I 

included 

• $1.5 million in SWIM funds allocated by the Legislature in 1996 

• 25% of invoices up to $4 million from Lake County and the Lake County Water 

Authority 

• $1 million from the EPA Clean Water Act fund 

Phase I construction was completed in 2001 for approximately $4.32 million. SJRWMD 

will start operation of the project when the currently low lake levels increase sufficiently 

and when discussions with federal agencies regarding pesticide residues in the soils are 

completed. The first phase of construction developed 4 of 13 treatment cells in the flowway. The design allows future construction phases to proceed while Phase I is fully 

operational. Phases II and III will be constructed as funding becomes available. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

86 

IMPROVE FOOD-WEB STRUCTURE

Gizzard Shad Harvest 

The purpose of the Trophic Structure Manipulation and Rough Fish Harvesting Projects 

is to remove “rough fish,” primarily gizzard shad (Dorosoma cepedianum). Shad harvest 

is a cost-effective means of removing phosphorus stored in the lake and helping change 

water quality and the trophic structure (animal community) of the lake toward 

conditions conducive to a diverse fish community with abundant game fish. The 

gizzard shad, presently the dominant fish in Lake Apopka, is a filter-feeding species 

that thrives in the current turbid, algal-dominated water of the lake. Its dominance 

reflects current poor quality conditions in the lake. The fish helps to maintain those 

conditions by increasing the rate at which the phosphorus in the water is made 

available for algal growth, by stirring up loose bottom sediments, and by removing the 

larger zooplankton grazers that more efficiently feed on blue-green algae. Removal of 

the gizzard shad population from Lake Denham, a 120-ha (300-ac) lake connected to 

downstream Lake Harris, between 1990 and 1992 provided a successful demonstration 

of the potential benefits of this restoration technique. Haul seine removal of gizzard 

shad from Lake Denham resulted in significantly improved water quality, including 

reductions in total phosphorus, nitrogen, suspended solids, turbidity, and chlorophyll a

concentrations and increased water clarity measured by Secchi disk. Recreational 

fishing improved dramatically as well. 

From 1993 through 2002, commercial fishermen harvested 3,729,945 kg (8.2 million 

pounds) of gizzard shad from Lake Apopka. A winter/spring harvest, supported by 

SJRWMD funding, is augmented by the availability of year-round permits for commercial 

fishermen that have yielded as much as 250,000 pounds annually without cost to 

SJRWMD. Low lake levels prevented large-scale harvest of gizzard shad in 2001 and the 

spring of 2002. To improve lake access for commercial fishing, a new dock facility was 

constructed in 2002 on McDonald Canal on the former A. Duda and Sons Jem Farm 

property. 

IMPROVE LAKE HABITAT

Littoral Zone Replanting 

Historically, the northern third of Lake Apopka was a vast floodplain wetland 

dominated by saw grass. A healthy littoral zone surrounded the rest of the lake, 

including a shallow-water habitat for fish population development. However, the 7,290 

ha (18,000 ac) of northern wetlands were eliminated and the remaining littoral zone is 
Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

87 

degraded, with loose sediments unsuitable for game fish nesting sites. Dense stands of 

cattail, which provide a poor habitat for fish (Johnson and Crumpton 1998), make up 

approximately 48% of the areal coverage of the existing near-shore vegetation 

(SJRWMD, unpublished data). 

In the Littoral Zone Restoration Project, desirable native vegetation is planted behind 

inexpensive, moveable breakwaters to reintroduce emergent wetland species lost to 

littoral zone areas and to begin to stabilize the loose surficial sediments. It is expected that 

in addition to providing the protection from wave action necessary for newly planted 

vegetation to establish and thrive, these breakwaters will help reduce sediment 

resuspension, clear the water column, and promote development of submerged 

vegetation. A contract effort to transplant six native aquatic plant species behind 

protective barriers and at unprotected control sites began in July 1992 and was completed 

in December 1993. Additional aquatic vegetation planting was begun by SJRWMD staff in 

June 1992, primarily on the northern shore of the lake. This is an ongoing effort, and over 

one noncontiguous mile of shoreline, comprising over 40 sites, has been planted 

(Figure 31). Planting “events” have been sponsored by SJRWMD with county and local 

governments and the Friends of Lake Apopka (FOLA) to restore littoral zone areas 

fronting public parks along the lake. Volunteers of all ages have participated in these 

events. Also, the existing shoreline vegetation around the 40-mile perimeter of the lake has 

been mapped using global positioning and geographic information systems (Conrow and 

Peterson 2000). This effort will establish a baseline for quantifying changes in future 

vegetative coverage. 

New Vegetation Development 

Since 1995, Vallisneria americana (eelgrass) has increased markedly in the lake after being 

nearly absent from the lake bottom in recent decades. By January 2001, more than 83 

patches with a combined area over 2.6 ha (6.5 ac) were documented. This spontaneous 

return of submersed macrophytes may be a response to improved underwater light 

conditions. In addition to providing valuable habitat, submersed macrophytes will 

hasten the recovery of the lake through several positive feedback mechanisms. 

Progress of the Lake Apopka Restoration Program 

St. Johns River Water Management District

89 

OTHER EFFORTS

Wetland Restoration Area Pesticide Residue Effort 

As discussed in the Overview section, two different evaluations were performed as 

steps in the land acquisition process at Lake Apopka: (1) an environmental site 

assessment (ESA) and (2) an environmental risk assessment (ERA). 

The ESA and subsequent remediation activities identified and removed highly 

contaminated soil from former storage areas, with mix/load sites, solid waste sites, etc. 

The ERA evaluated the potential for acute or long-term (chronic) problems to occur 

with wildlife as a result of the average pesticide residue concentrations in the purchased 

areas that resulted from normal farming operations. 

All properties considered for acquisition received a Phase I ESA in accordance with 

American Society for Testing and Materials (ASTM) Standard E1527. Eleven properties 

were audited, although not all of these properties are part of the currently active 9,000-

acre restoration area. 

Final remediation included removal of over 18,600 tons of soil that were contaminated 

by petroleum, metals, and pesticides. SJRWMD also conducted an ERA of the residual 

pesticide levels expected to remain in the farm soils after remediation was completed. 

Approximately 400 soil samples were analyzed for pesticide residues in the ERA 

process. The risk assessment and subsequent follow up evaluation indicated no 

likelihood that background residual pesticide levels would present an acute toxicity risk 

to aquatic or wetland animals. Some concerns about long-term, sub-lethal effects on 

growth or reproduction were raised, and SJRWMD planned a monitoring program to 

assess these potential problems during restoration. 

The promotion of lush emergent vegetation through shallow flooding was identified as 

the best management strategy to remediate the background levels of pesticides. This 

approach combined the beneficial effects of (1) a halt to further application of pesticides, 

(2) accelerated microbial breakdown of pesticides in a nutrient-rich, anaerobic soil 

environment, and (3) burial and dilution of the pesticide residues with new organic 

matter. 

Flooding the Farm Fields and Bird Mortality 

Remediation activities at the farms were completed during the summer of 1998, and the 

farms were shallowly flooded. Shallow flooding of the farm fields was the farmers’ 

historical practice to control crop pests and reduce erosion during the summer fallow 
SWIM Plan for Lake Apopka 

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period. Shallow flooding was extended into the fall in order to expedite restoration 

efforts, specifically to 

• Limit weed growth to facilitate soil amendment application 

• Minimize pumping of drainage water to Lake Apopka 

• Provide habitat for migrating shorebirds 

As autumn progressed, an enormous number and variety of birds came to the site. 

SJRWMD began draining the site in early November to prepare for treatment of the area 

with a soil amendment to trap excess phosphorus left by the farming process. The range 

of water depths created in the NSRA as fields began to dry resulted in an extraordinary 

response by bird populations. The 1998 Zellwood/Mount Dora Christmas Bird Count 

recorded a likely North American inland record of 174 species (Cornell University 2002). 

However, in late fall 1998, a significant mortality event affecting primarily white pelicans 

occurred on the site. Birds were also found sick or dead in other parts of Florida. The 

deaths of about 1,000 white pelicans and other fish-eating birds statewide have been 

attributed to the mortality event on the north shore of Lake Apopka. The number of 

dead pelicans represented a significant fraction of the white pelican population 

wintering in Florida. 

In order to discourage fish-eating birds from coming to the area, SJRWMD accelerated 

draining of the farmland in January 1999. The fields were completely drained by 

February. By March, the pelican population had migrated from the sites and mortalities 

of all bird species were infrequent. 

Investigating the Causes of the Bird Mortality 

USFWS, the federal agency responsible for migratory birds and federally listed species, 

began an investigation of the bird mortality shortly after the deaths began. On February 

17, 1999, USFWS issued a press release with a preliminary conclusion that the birds had 

died from poisoning by organochlorine pesticides. Among the pesticides that were 

implicated are toxaphene, dieldrin, and DDT and its metabolites. 

SJRWMD and NRCS, with the concurrence of other Florida government agencies, 

determined that further investigation was necessary. A total of $1.5 million for Phase 1 

of the study was pledged from SJRWMD and NRCS, and other organizations pledged 

in-kind support. In March 1999, a team of experts from 13 federal, state, county, and 

private organizations convened as the technical advisory group to the investigation. 
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Using the USFWS conclusions as a working hypothesis, the technical advisory group 

investigation was designed to evaluate two potential hypotheses. The first hypothesis 

was that typical pesticide concentrations in the fields were sufficiently high to cause 

acute toxicity. The second hypothesis was that a highly contaminated site was not 

found during the ESAs conducted for each farm. 

All data on soils and sediments, birds, and fish were provided to Exponent Inc., a 

consulting firm based in Bellevue, Washington. Their analysis of the data and a draft 

report on the mortality event were completed for review in September 2000. The draft 

Exponent report generated significant debate among the technical advisory group and 

others as to the cause of the bird mortality. In April 2001, USFWS released a significant 

amount of data that it had obtained through necropsies conducted by USFWS on birds 

that were sequestered by USFWS after the bird mortality. These data, along with technical 

review comments, were then made available to Exponent for preparation of the final 

report. A further draft was received in April 2003. 

A primary uncertainty for evaluating risk from pesticide residues is the rate of 

bioaccumulation of pesticides from soils/sediments through the food chain to fish and 

then to birds. Soils with high organic matter contents, like those on the NSRA have not 

been studied, nor has environmental fate modeling for pesticides been evaluated under 

similar high organic conditions. Therefore, three additional phases of study are necessary 

initial components of restoration efforts for the NSRA: (1) laboratory microcosms, (2) fieldscale mesocosms, and (3) bird feeding studies. SJRWMD initiated these studies during the 

spring of 2001. 

In addition to the above studies, SJRWMD started cleanup of a small, highly contaminated 

area during 2002. Through January 2003, a total of 9,203 tons of contaminated soil had 

been excavated. This site was discovered during the intensive soil sampling conducted in 

1999. Also as a result of the intensive sampling and subsequent risk analysis, SJRWMD 

developed and submitted to NRCS a plan for reflooding a portion of the Duda farm. This 

700-acre area had the lowest pesticide concentrations found on the NSRA, with soil 

concentrations below all thresholds suggested by Exponent (2000). Reflooding was 

initiated in June, 2002 and will be accompanied by intensive monitoring of water 

chemistry, hydrology, bird use, and pesticide residues in fish, sediments, and water. 

Finally, additional soil sampling for pesticides has been completed on portions of the 

NSRA not involved in the mortality event. 

After any necessary remediation is complete, SJRWMD will flood the site to begin 

shallow marsh development. The present long-term restoration plan includes several 

potential management areas such as shallow marsh, deep marsh connected to the lake, 

and shorebird management areas. As final restoration activities are developed, 
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SJRWMD may consider and implement other appropriate management alternatives as 

well. 

Further information on the bird mortality, pesticide study objectives, and possible 

remediation methods is found in the Detail of Projects section under Project 

LA-3-303-M: Wetland Restoration. 

Future Basin Management Alternatives 

The restoration projects outlined above will continue beyond the time horizon covered 

by this plan. Because these restoration efforts represent a large investment of time and 

resources, important consideration will be given to protecting the quality of the water 

body during and after restoration. 

One important effort toward that end is the Lake Apopka Basin Planning Initiative, 

initiated by FOLA, a coordinated regional planning effort involving local elected 

officials, the East Central Florida Regional Planning Council (ECFRPC), SJRWMD, and 

other interested parties. In 2000, a steering committee consisting of local elected officials 

from the two counties and six municipalities in the basin examined needs and 

opportunities relating to five areas considered to be key pieces for achieving an 

ecologically and economically sustainable future for the basin. Those five areas are 

shoreline protection, greenways and trails, viewsheds, public access, and natural 

setting. 

One major opportunity identified through the initiative is development of a recreational 

trail around Lake Apopka. Using a concept plan prepared by ECFRPC, FOLA is 

promoting a detailed study of ways such a trail could link all the municipalities in the 

basin and SJRWMD lands within a 50+ mile loop. Also, a resident’s group in Lake 

County is attempting to have County Road 455 on the west side of the lake designated 

as a Florida Scenic Highway in an effort to feature and protect environmental and 

cultural resources in the western portion of the basin. A similar group is organizing 

around old Highway 50 in Oakland. 

Using a grant from Orange County, FOLA hired professional planners to develop the 

Lake Apopka Development Design Guidelines. Each of the eight local jurisdictions will 

be asked by FOLA to adopt and apply the shoreline protective measures as they 

approve future developments. Lake County has written a new ordinance based on the 

guidelines and several new proposed developments have incorporated the guidelines. 

The Jones Avenue Regional Stormwater Management Project will provide a regional 

wet detention pond system to improve the water quality in the northern portion of the 
Progress of the Lake Apopka Restoration Program 

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basin. The 16-ha (40-ac) project will be located on SJRWMD property within the NSRA 

and will be funded by a cost-share agreement between SJRWMD and Orange County. 
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Programs and Projects 

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PROGRAMS AND PROJECTS

This section contains an overview of programs and projects to be implemented in the 

Lake Apopka SWIM Plan. All of the projects are categorized under the following eight 

programs: 

1. Diagnostic Program—studies to collect necessary information on Lake Apopka. This 

includes studies designed to further understand the functioning of the lake and the 

causes of its degradation. 

2. Feasibility Program—investigation and testing of potential restoration techniques. 

3. Restoration Program—demonstration and full project restoration efforts. This will 

include implementation of techniques developed as pilot studies under the 

Feasibility Program. 

4. Regulatory Program—compliance enforcement actions regarding point and 

nonpoint source pollution. An assessment and development of regulatory needs and 

a compilation of a database necessary to promulgate additional regulatory criteria 

will be completed. 

5. Planning Program—planning and coordination of efforts with state agencies and 

local governments. Efforts will be closely coordinated with the Regulatory Program. 

6. Public Information Program—public information and awareness efforts. 

7. Land Acquisition Program—acquisition planning and acquisition. 

8. Technical Support Program—support activity such as budget preparation, project 

planning, integration of diagnostic and feasibility projects, data management, and 

SWIM Plan revisions 

PROJECT CODING

Each project has been assigned a code. The code has (1) a two-letter prefix to identify 

the water body (e.g., LA = Lake Apopka), (2) a single-digit number which relates the 

project to the most applicable central concern of the SWIM Act (e.g., LA-1 = Lake 

Apopka, point and nonpoint source pollution central concern), (3) a three-digit number, 

the first to identify the appropriate program and the remaining digits to identify each 
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project (e.g., LA-1-105 = Lake Apopka, point and nonpoint source pollution central 

concern, diagnostic program, project number five), and (4) a single-letter suffix (D, F, M, 

or S) for a budget code (e.g., LA-1-105-D = Lake Apopka, point and nonpoint source 

pollution central concern, diagnostic program, project number five, diagnostic fiscal 

budget code). The code segments for the Lake Apopka SWIM Program follow. 

Prefix: LA—Lake Apopka 

Central concerns of the SWIM Act: 

• Point and nonpoint source pollution 

• Destruction of natural systems 

• Correction and prevention of surface water problems 

• Research for better management of surface waters and associated natural systems 

• Public awareness 

• Improved coordination and management 

Programs: 

 100 series Diagnostic Program 

 200 series Feasibility Program 

 300 series Restoration Program 

 400 series Regulatory Program 

 500 series Planning Program 

 600 series Public Information Program 

 700 series Land Acquisition Program 

 800 series Technical Support Program 

Suffix: 

 D Diagnostic 

 F Feasibility/Applied Research 

 M Management/Restoration 

 S Technical Support 

PROGRAM AND PROJECT DESCRIPTIONS

The following are brief descriptions of complete, ongoing, and proposed projects for 

Lake Apopka. Each project is described in detail in the following section. 
Programs and Projects 

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97 

A. Diagnostic Program 

1. External Nutrient Budget 

 LA-1-101-D 

 Quantifies the exchange of water and nutrients between Lake Apopka and its 

watershed. 

2. Internal Nutrient Budget 

 LA-1-102-D 

 Maps the type, depth, and chemical characteristics of lake sediments. Quantifies 

nutrients returning from the sediments to the water and examines sediment 

deposition rates in the Lake Apopka Basin. 

3. Mathematical Modeling 

 LA-4-103-D 

 Uses data collected in the diagnostic and feasibility programs to project the effects of 

selected restoration techniques. 

4. Phytoplankton-Nutrient Interactions 

 LA-4-104-D 

 Provides baseline information on algal biomass and productivity. Assesses the 

consequences of nutrient reduction on algal growth. 

5. Bathymetry 

 LA-4-106-D 

 Provides a bathymetric survey of the bottom contours of Lake Apopka. 

6. Fishery 

 LA-4-107-D 

 Obtains current information on the fishery in Lake Apopka for modeling purposes. 

Monitors the game and rough fish populations. 

7. Seismic Reflection Profiling 

 LA-1-108-D 

 Examines subsurface geology across Lake Apopka and assesses the nature of the 

confining layers between the lake and the Floridan aquifer. 

8. Hydrodynamic Survey 

 LA-4-109-D 

 Characterizes the dominant seasonal meteorological conditions and models 

velocities and directions of water currents in selected portions of the lake. 
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B. Feasibility Program 

1. Water Hyacinth Demonstration 

 LA-4-201-F 

 Tests the ability of water hyacinths to remove nutrients from the lake. 

2. Phosphorus Inactivation/Precipitation 

 LA-4-202-F 

 Evaluates the feasibility of using alum as a precipitant to trap nutrients in an 

insoluble matrix. 

3. Sediment Recycling 

 LA-4-204-F 

 Evaluates dredging costs and potential markets for lake sediment to make dredging 

economically feasible. 

4. Microbial Decomposition 

 LA-4-205-F 

 Evaluates ways of stimulating natural microbial processes which reduce the bulk of 

lake sediments and sequester nutrients. 

5. Ichthyofaunal Reconstruction (I, II) 

 LA-4-206-F 

 Phase I—Compiles a literature review on biomanipulation to determine applicability 

to problems in Lake Apopka. Phase II—Evaluates the potential for use of exotic fish 

species to aid in the restoration of Lake Apopka by consumption of excess 

production of algae. 

6. Trophic Structure Manipulation (I, II, III) 

 LA-4-207-F 

 Phase I—Provides baseline data on the role of rough fish in plankton and nutrient 

dynamics. Phase II—Determines the effects of gizzard shad removal on lake trophic 

structure and nutrient recycling. Phase III—Tests standard harvesting gear for largescale rough fish removal in Lake Apopka and tests feasibility of using harvested 

rough fish as marketable products to offset the cost of fish removal. 

7. Drawdown and Lake Level Fluctuation (I, II, III) 

 LA-4-208-F 

 Phase I—Evaluates the feasibility and ecological effects of temporary lowering the 

water level in the lake or enhancing water level fluctuation. Phase II—Examines the 

effects of a partial drawdown of a similar nearby lake. Phase III—Formulates 
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alternative enhanced lake fluctuation schedules, assesses socioeconomic 

consequences, and recommends new regulation schedules. 

8. Socioeconomic Assessment and Methodology 

 LA-4-209-F 

 Develops techniques for socioeconomic assessment of the Lake Apopka Basin. 

Assesses the present economic value of the recreational and commercial uses of Lake 

Apopka and predicts economic growth with water quality improvement. Assesses 

the impact of a total farm buyout on the local economy. 

C. Restoration Program 

1. Marsh Flow-Way Restoration 

 LA-3-301-M 

 Restores muck farmland to a treatment marsh in order to filter nutrient-rich water 

from Lake Apopka. 

2. Rough Fish Harvesting 

 LA-3-302-M 

 Harvests rough-fish species to remove nutrients from Lake Apopka and improves 

water quality through food-web manipulation. 

3. Wetland Restoration 

 LA-3-303-M 

 Restores acquired properties to wetland habitat and examines restoration for effects 

upon water quality, vegetation, and wildlife. 

4. Littoral Zone Restoration 

 LA-2-304-M 

 Evaluates the feasibility of isolating and restoring small portions of Lake Apopka’s 

shoreline to vegetated littoral zone and examines the potential macrophyte seed 

source from littoral zone sediments. 

D. Regulatory Program 

1. Nonpoint Source Pollution Control 

 LA-3-402-M 

 Identifies and controls sources of nonpoint pollution affecting Lake Apopka. 

2. Nutrient Loading Limits Adoption 

 LA-3-403-M 
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 Develops and adopts more-stringent permitting criteria, as necessary, to protect 

water resources in the Lake Apopka Basin from future development and establishes 

numerical nutrient loading limits. 

E. Planning Program 

1. District Water Management Plan 

 LA-6-501-M 

 Provides a means to identify and address water resource issues. 

2. Local Government Comprehensive Plan Review 

 LA-6-502-S 

 Reviews and comments on local government comprehensive plans. 

3. Land Management Plan for the Lake Apopka Restoration Area 

 LA-6-503-M 

 Develops land management plan for the entire Lake Apopka restoration effort. 

F. Public Information Program 

1. Public Awareness 

 LA-5-602-S 

 Uses media communication techniques to inform and educate the public regarding 

ongoing and future restoration efforts for Lake Apopka. 

2. Local Government Information Project 

 LA-5-603-S 

 Makes formal informational SWIM program presentations to Planning 

Commissions, County Commission Boards, and other municipal advisory and 

governing bodies. 

G. Land Acquisition Program 

1. Marsh Flow-Way Land Acquisition 

 LA-3-701-S 

 Acquires 2,360 ha (5,833 ac) of farmland in support of the Marsh Flow-Way Project. 

2. North Shore Land Acquisition 

 LA-3-704-S 
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 Evaluates potential acquisitions of muck farms and adjacent conservation and 

preservation lands in the Lake Apopka Basin, prioritizes purchases, and acquires 

lands. 

H. Technical Support Program 

1. Implementation of Restoration and Management Techniques 

 LA-6-802-S 

 Provides overall analysis and coordination of diagnostic, feasibility, regulatory, 

planning, and pilot restoration projects. 

2. Restoration Monitoring and Analysis 

 LA-6-803-S 

 Implements a post-restoration monitoring regime. 

3. Overall Program Management 

 LA-6-804-S 

 Manages Lake Apopka SWIM Program. Provides inter-agency coordination and 

report preparation, as necessary. 
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Detail of Projects 

St. Johns River Water Management District

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DETAIL OF PROJECTS

Diagnostic projects further our understanding of the functioning of the lake and the 

causes of its degradation. Feasibility projects are directed toward investigation and 

testing of potential restoration techniques. Of the 16 diagnostic and feasibility projects 

discussed within this section, no further action is planned for 13. The remaining three 

projects are ongoing, some with expanded scopes of work. Successful completion of 

these studies represents a major milestone. A number of restoration techniques 

originally proposed for Lake Apopka were found upon examination to be inefficient or 

ineffective. These techniques include large-scale sediment recycling, phosphorus 

inactivation in the lake sediments, microbial decomposition, and ichthyofaunal 

reconstruction. The decision not to proceed with pilot-scale implementation of these 

techniques has freed resources to support the restoration methods that have been 

shown to be effective for this lake. 

The following individual project presentations contain a priority code assigned to the 

project, an issue category which refers to the seven priority issues, an objective, a scope 

of work, and a status report. Each project is related to the central concerns of the SWIM 

Act by applicable intent and focus. Schedules through fiscal year 2005–2006 are 

included for projects that are incomplete or ongoing. Timelines for Lake Apopka 

projects over the planning period of this document are illustrated in Figure 32. 

PROJECT (LA-1-101-D): EXTERNAL NUTRIENT BUDGET

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORIES: Agricultural discharges; poor water quality and flocculent 

sediments 

PROJECT OBJECTIVE: To quantify all interchanges of water and nutrients between 

Lake Apopka and its environment by monitoring surface and subsurface flow, rainfall 

and dry deposition, evaporation, and pump discharges from farms and restoration 

areas 
Figure 32. Overall timetable for the Lake Apopka SWIM Program 

St. Johns River Water Management District

104 

SWIM Plan for Lake Apopka 
Figure 32—Continued 

St. Johns River Water Management District

105

Detail of Projects
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

106 

SCOPE OF WORK: Conduct full-scale monitoring during calendar years 1989 and 1990. 

Continue nutrient monitoring after 1990 as part of ongoing project. External sources of 

nutrients and water include the following: precipitation, tributaries, muck farms (new 

SJRWMD restoration areas), Apopka Spring, direct overland runoff, groundwater 

seepage, and industrial and municipal point sources. Losses of nutrients and water 

occur through the Apopka-Beauclair Canal, muck farm (restoration area) withdrawals, 

removal by fish harvesting, seepage, and evaporation. During the full monitoring 

period, implement a telemetry network to provide meteorological data: temperature, 

solar radiation, wind speed, precipitation, barometric pressure, evaporation, and 

relative humidity. Monitor permanent tributaries with the radio telemetry system and 

seasonal tributaries manually, once a month. Sample monthly water quality at all 

flowing tributaries, at Apopka Spring, at stations located in the lake, and at the ApopkaBeauclair Canal. Monitor agricultural discharge by event at nine point discharges from 

the Lake Apopka muck farms. Quantify domestic and industrial discharges provided 

through monthly operating reports to FDEP. Characterize groundwater quality with 

monthly samples of shallow aquifer wells located around the lake. Measure subsurface 

seepage with a network of piezometers located along the dikes and around the lake. 

Monitor flow continuously at the Apopka-Beauclair and Lake Level canals. Develop an 

FDEP-approved Quality Assurance Plan. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project provides the 

necessary data to calculate a water budget for the lake and to quantify external nutrient 

loads to the lake. Such information has been used in enforcement compliance, 

regulation planning, and planning a restoration program for the lake. Information on 

response of the lake to past development will help in evaluation of the effects of present 

and future land use. External nutrient loading data will also provide a basis to evaluate 

recent and future effects of nutrient reductions and of other restoration measures in the 

lake. 

SUMMARY AND STATUS: Nutrient loading to the lake is calculated by combining the 

results of a water budget analysis with water quality measurements. This is a difficult 

process, which requires a large amount of accurate data to account for the inherent 

variability in field data from a complex system. The quality assurance plan was 

approved by FDEP (then, FDER) in January 1989. 

Monitoring of hydrologic variables with the full telemetry sensor net and water quality 

sampling proceeded during calendar years 1989 and 1990. From 1991 to 1998, SJRWMD 

efforts focused on monitoring of atmospheric deposition, ambient water quality, and 

discharges from the Apopka-Beauclair Canal. Other data on phosphorus loading to the 

lake and losses from the lake were compiled from farmers’ consent order reports and 

from industrial and domestic wastewater discharge permit compliance reports. A draft 
Detail of Projects 

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technical memorandum describing a six-year (1989–94) phosphorus budget for Lake 

Apopka was completed (see Appendix H). After acquisition of most of the agricultural 

area in 1998, SJRWMD again began monitoring nutrient discharges from that area. 

One source of water to Lake Apopka is Apopka Spring (Gourd Neck Spring). The 

orifice of the spring is covered by natural and man-made debris and is irregular in 

shape, which creates difficulty in obtaining accurate measurements. Therefore, a 

substantial discharge variability (31.4 to 70.4 cubic feet per second) was evident in the 

six spring discharge measurements made by USGS in Apopka Spring from 1988 to 1992. 

In order to more precisely predict Apopka Spring’s contribution to the water quality 

and quantity of Lake Apopka, 15 additional discharge measurements were taken by 

Karst Environmental Services between May 1997 and June 1999 inside the spring vent. 

These measurements were used to refine the relationship between Floridan aquifer and 

Lake Apopka elevations and spring flow so that spring discharges could be estimated. 

A 1996 assessment of muck farm development using aerial photography from 1941 to 

1990 provided a clearer picture of the historical loading changes that Lake Apopka has 

undergone (see Figure 4). Monitoring and analysis of nutrient loading and water 

quality for Lake Apopka during the implementation of the restoration program are 

accomplished under Project LA-6-803-S: Restoration Monitoring and Analysis. 

Reports

Bryant, C.T. 1990. A groundwater flow analysis and cost of sampling program for Lake Apopka. 

M.S. thesis, University of Florida, Gainesville. 

Bryant, C.T., and S.F. Shih. 1990. A groundwater flow analysis of Lake Apopka, Florida. Final 

report to St. Johns River Water Management District. IFAS, University of Florida, 

Gainesville. 

———. 1990. Hydraulic conductivity analysis of inflow and outflow regions adjacent to Lake 

Apopka, Florida. In Proceedings of the Soil and Crop Science Society of Florida 49:32–36. 

———. 1991. Site vs. regional analyses of the groundwater flow in Lake Apopka, Florida. In 

Proceedings of the Soil and Crop Science Society of Florida 50:117–122. 

Karst Environmental Services, Inc. 1999. Results of discharge measurements of Lake Apopka 

Gourdneck Spring, Lake County, Florida. Fifteen reports from May 14, 1997, to June 16, 

1999. Contract 97W285, prepared for St. Johns River Water Management District, Palatka, 

Fla. 
SWIM Plan for Lake Apopka 

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Schiffer, D.M. 1994. Quality of water and bottom sediments, and nutrients and dissolved solids loads in 

the Apopka-Beauclair Canal, Lake County, Florida, 1986–90. Water-Resources Investigations 

Report 93-4103. Tallahassee, Fla.: U.S. Geological Survey. 

[SJRWMD] St. Johns River Water Management District. 1988. QA project plan for external 

nutrient loading study. Palatka, Fla. 

Stites, D.L., M. Coveney, L. Battoe, E. Lowe, and V. Hoge. 2001 (draft). An external phosphorus 

budget for Lake Apopka, 1989–1994. Technical memorandum. St. Johns River Water 

Management District, Palatka, Fla. 

PROJECT (LA-1-102-D): INTERNAL NUTRIENT BUDGET

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To map the type, depth, distribution, and quality of lake 

sediments, and to quantify internal nutrient dynamics in the lake; to examine the 

dynamics of nutrient conversion and exchange with the atmosphere due to processes 

such as gaseous nitrogen fixation, denitrification, carbon fixation, and respiration 

SCOPE OF WORK: Take intact sediment cores at 100 sampling stations that 

approximate the locations sampled in 1968 by Schneider and Little (1969). Compare 

data between the two studies to provide an indication of changes in sediment 

characteristics over the intervening 19-year period. Process the cores to determine rates 

of accumulation of organic carbon, aerobic and anaerobic decomposition zones, spatial 

variation in organic sediment depth, and concentrations of different forms of carbon, 

nitrogen, and phosphorus. Determine the net flux of dissolved nutrients from the 

sediments to the overlying water column, the importance of biological and physicochemical transformation of sedimentary nutrients, and the rates of transformation. 

Analyze sediments for metals, volatile and semi-volatile organic compounds, and 

pesticides. Utilize diatom analysis and 210Pb dating techniques to evaluate sediment 

characteristics of the sediment layers and accumulation rates. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will provide 

the data necessary to evaluate internal nutrient loading and recycling in Lake Apopka 

and provide a basis for simulation models to predict how internal loading can be 

reduced. 
Detail of Projects 

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SUMMARY AND STATUS: The original contractual projects were completed and the 

final report was prepared in two parts. Phase I was accepted by the Governing Board in 

March 1991. Phase II was accepted by the Governing Board in May 1991 and revised in 

December 1992. Additional research based on the results of the administrative hearing 

on the Lake Apopka Nutrient Limitation Rule, which became Phase III, was completed 

and approved by the Governing Board in 1997. 

Phase I—The Internal nutrient budget for Lake Apopka, completed by a University of 

Florida research team, provides a compendium of basic data from chemical and 

physical analyses on sediment samples from a 90-station grid over the bottom of Lake 

Apopka (Reddy and Graetz 1991). These data have been used in the report to map 

sediment type and thickness. SJRWMD staff have used the data to estimate available 

nutrient stores in the sediments and to provide a measure of permanent burial of 

phosphorus. The basic information in this report is central to our understanding of the 

role that the sediments in Lake Apopka play during the restoration process. The report 

also provides measurements of various exchange rates between the sediments and lake 

water for the nutrients carbon, nitrogen, and phosphorus. Design and evaluation of 

restoration projects and establishment of loading limits for Lake Apopka have relied 

and will continue to rely heavily on data provided in this report. 

Phase II—Assessment of potential sediment contamination for the restoration of Lake Apopka

presented a survey of levels and potential toxic effects of substances in Lake Apopka 

sediments (Segal and Pollman 1991). Sediment cores from two depths at 10 locations 

were analyzed by KBN Engineering and Applied Sciences for the 152 elements and 

compounds on the EPA Toxic Compounds List. Thirteen elements occurred in 

sufficiently high concentrations to warrant detailed examination; two (copper and lead) 

appear to pose the greatest threat of toxicity to the lake biota. Because of the complexity 

of interactions that occur in biological systems, the potential toxic effects of these 

elements are difficult to assess. SJRWMD staff have enlisted the support of other state 

agencies in determining the need for further studies, such as fish tissue analyses. 

Phase III—Research on internal nutrient dynamics stemming from the results of the 

administrative hearing on the Lake Apopka Nutrient Limitation Rule focused on 

evaluating sediment characteristics of the sediment layers and accumulation rates using 

methods independent of previous research in this area. In 1996, a research group at UF 

under the direction of Dr. Claire Schelske was awarded a contract to further research 

the development and characteristics of the lake sediments using diatom analysis and 210Pb dating techniques (Appendix H). The final report was approved by the Governing 

Board in December 1997. Diatom analysis indicates two distinct sediment layers, the 

upper layer from a phytoplankton-based system and the lower layer from a 
SWIM Plan for Lake Apopka 

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110 

macrophyte-dominated system (Schelske 1997). This comparison indicates that 

calculated storage of organic matter closely approximates storage evaluated 

independently. The whole-basin inventory of total phosphorus in flocculent sediments 

was estimated at 2,250 metric tons. 

Reports

Aldridge, F.J., C.L. Schelske, and H.J. Carrick. 1993. Nutrient limitations in a hypereutrophic 

Florida lake. Arch. für Hydrobiologie 127(1):21–37. 

Gale, P.M., and K.R. Reddy. 1994. Carbon flux between sediment and water column of a 

shallow, subtropical, hypereutrophic lake. J. Environ. Qual. 23:965–972. 

Moore, P.A., Jr., K.R. Reddy, and D.A. Graetz. 1991. Phosphorus geochemistry in the sedimentwater column of a hypereutrophic lake. J. Environ. Qual. 20:869–875. 

Newman, S., and K.R. Reddy. 1993. Alkaline phosphatase activity in the sediment-water 

column of a hypereutrophic lake. J. Environ. Qual. 22(4):832–838. 

Olila, O.G., and K.R. Reddy. 1995. Influence of pH on phosphorus retention in oxidized lake 

sediments. Soil Sci. Soc. Am. J. 59:946–959. 

———. 1997. Influence of redox potential on phosphate-uptake by sediments in two subtropical eutrophic lakes. Hydrobiologia 345:45–57. 

Reddy, K.R., and D.A. Graetz. 1991. Internal nutrient budget for Lake Apopka. Special Publication 

SJ91-SP6. Palatka, Fla.: St. Johns River Water Management District. 

Reddy, K.R., M.M. Fisher, and D. Ivanoff. 1996. Resuspension and diffusive flux of nitrogen and 

phosphorus in a hypereutrophic lake. J. Environ. Qual. 25:363–371. 

———. 1996. Sediment studies in Lake Apopka, Phase I, interim report, October 15, 1995–

January 15, 1996. St. Johns River Water Management District Contract 96W136. Department 

of Fisheries and Aquatic Sciences, University of Florida, Gainesville. 

———. 1997. Sediment and phosphorus deposition in Lake Apopka. Final report. Special Publication 

SJ97-SP21. Palatka, Fla.: St. Johns River Water Management District. 

Schelske, C.L., F.J. Aldridge, and H.J. Carrick. 1992. Phytoplankton-nutrient interactions in Lake 

Apopka. Special Publication SJ92-SP9. Palatka, Fla.: St. Johns River Water Management 

District. 

Schelske, C.L., C.M. Donar, and E.F. Stoermer. 1999. A test of paleolimnological proxies for the 

planktonic/benthic ratio of microfossil diatoms in Lake Apopka. In 14th International Diatom 
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Symposium. Mayama, Idei, and Koizumi, eds., 387–407. Tokyo, Japan: Koeltz Scientific 

Books. Koenigstein. 

Segal, D.S., and C.D. Pollman. 1991. Assessment of potential sediment contamination for the 

restoration of Lake Apopka. Special Publication SJ91-SP8. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT (LA-4-103-D): MATHEMATICAL MODELING

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORIES: Agricultural discharges; poor water quality and flocculent 

sediments; degradation of downstream lakes 

PROJECT OBJECTIVE: To develop simulation models with data collected in the 

diagnostic and feasibility projects to project the effects of selected restoration techniques 

SCOPE OF WORK: Develop conceptual and mathematical models to help understand 

the present condition of the lake, how that condition is maintained, and what effects 

different restoration treatments will have. Build models that will simulate conditions in 

the lake by mathematically defining and linking processes that describe lake system 

functions. Simulate management alternatives and their effects by changing the rates and 

levels at which the different processes occur and defining new processes that describe 

restoration methods. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will provide a 

predictive capability to determine the allowable phosphorus loading consistent with the 

restoration of Lake Apopka. The project also will predict effects of proposed restoration 

techniques on lake water quality. 

STATUS: Model formulation and testing proceeded concomitant with data collection. 

Input-output models were developed to predict the effect of removal of phosphorus in 

the marsh flow-way on phosphorus levels in the lake. Models also were used to 

determine the allowable phosphorus loading (from all sources) consistent with 

restoration goals. 
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Report

Coveney, M.F. 2000 (draft). Sedimentary phosphorus stores, accumulation rates, and 

sedimentation coefficients in Lake Apopka. Prediction of the allowable phosphorus loading 

rate. Technical memorandum. St. Johns River Water Management District, Palatka, Fla. 

PROJECT (LA-4-104-D): PHYTOPLANKTON-NUTRIENT INTERACTIONS

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To provide baseline information on algal biomass and 

productivity. Nutrient and light limitation will be assessed to enable prediction of the 

effects of restoration measures on algal growth. 

SCOPE OF WORK: Evaluate the methodology and the utility of physiological indicators 

of phytoplankton nutrient status in Lake Apopka, including assays for N and P 

limitation in the lake water. Develop procedures to measure daily phytoplankton 

primary production in vertical profiles using light-dark bottle methodology. Sample the 

center lake station twice per month; conduct assays for N and P limitation and 

phytoplankton primary production, and measure water column light extinction 

concurrently. Determine photosynthesis as a function of light intensity for lake 

phytoplankton. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will establish 

baseline levels of algal biomass and production, which are primary symptoms of 

eutrophication. Data on nutrient limitation conditions for algae are critical for 

evaluating the potential effects on algal growth of nutrient reduction through 

restoration activities. 

SUMMARY: In May 1989, SJRWMD entered a contract with UF, Department of 

Fisheries and Aquaculture, to conduct field measurements and experiments to monitor 

the growth and nutrient status of algae (phytoplankton) in Lake Apopka. The report 

provides important data on which management decisions can be based and from which 

the results of management decisions can be assessed. The last historical data were from 

1977 and 1978. 
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Phytoplankton biomass is high in Lake Apopka and is controlled partly by wind-driven 

resuspension of settled algae. Phytoplankton are responsible for approximately half of 

the light absorption of Lake Apopka water. Phytoplankton production is high and 

without distinct seasonality. Production levels were similar to those measured in 1977 

and 1978. 

Monthly experiments showed a primary nitrogen limitation to growth 96% of the time, 

with secondary phosphorus limitation about 25% of the time. Phytoplankton are 

nitrogen-limited because of cellular storage of phosphorus from excessive loading to the 

lake. Phosphorus loading must be reduced to reduce algal levels. Experiments provided 

evidence that, as algal levels are reduced through filtration of lake water through the 

marsh flow-way, remaining algae will be enriched in phosphorus. These processes 

should improve efficiency of phosphorus removal in the flow-way. 

Reports

Belanger, T.V. 1981. Benthic oxygen demand in Lake Apopka, Florida. Water Res. 15:267–274. 

Carrick, H.J., and C.L. Schelske. 1997. Have we overlooked the importance of small 

phytoplankton in productive waters? Limnol. Oceanog. 42(7):1613–1621. 

Carrick, H.J., F.J. Aldridge, and C.L. Schelske. 1993. Wind influences phytoplankton biomass 

and composition in a shallow, productive lake. Limnol. Oceanog. 38(6):1179–1192. 

Carrick, H.J., C.L. Schelske, F.J. Aldridge, and M.F. Coveney. 1993. Assessment of 

phytoplankton nutrient limitation in productive waters: Application of dilution bioassays. 

Can. J. Fish. Aquat. Sci. 50(10):2208–2221. 

Kenney, W.F., C.L. Schelske, and A.D. Chapman. 2001. Changes in polyphosphate 

sedimentation: A response to excessive phosphorus enrichment in a hypereutrophic lake. 

Can. J. Fish. Aquat. Sci. 58(5):879–887. 

Schelske, C.L. 1994. Assessing nutrient limitation in a hypereutrophic lake. Lake Reserv. Manage.

9(2):112. 

Schelske, C.L., F.J. Aldridge, and H.J. Carrick. 1992. Phytoplankton-nutrient interactions in Lake 

Apopka. Special Publication SJ92-SP9. Palatka, Fla.: St. Johns River Water Management 

District. 

Schelske, C.L., M.F. Coveney, F.J. Aldridge, W.F. Kenney, and J.E. Cable. 1999. Wind or 

nutrients: Historic development of hypereutrophy in Lake Apopka, Florida. T. Berman, ed. 

In Proceedings from the Kinneret Symposium on Limnology and Lake Management 2000+, 

September 6–11, 1999, Tiberias, Israel. 
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Shumate, B.C., C.L. Schelske, T.L. Crisman, and W.F. Kenney. 2002. Response of the cladoceran 

community to trophic state change in Lake Apopka, Florida. Journal of Paleolimnology

27:71-77. 

PROJECT (LA-4-106-D): BATHYMETRY

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To conduct a new bathymetric survey of Lake Apopka 

SCOPE OF WORK: Map the bottom contours of Lake Apopka using a recording 

fathometer on a 600-m (2000-ft) or smaller grid pattern. From the bathymetric data 

obtained, draw publication quality bathymetric and water depth maps of the lake (in 

metric and foot scales) with isopleth intervals of 0.25 m and 1.0 ft. Calculate stage-area 

and stage-volume relationships. Make quantitative analyses of errors and provide 95% 

confidence limits for the several relationships developed. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will provide 

an up-to-date bottom contour profile of Lake Apopka. Accurate bathymetric data are 

essential for the engineering of restoration projects and to evaluate future changes in 

bottom contours resulting from restoration efforts. 

SUMMARY: The field survey was completed in June 1989. The Governing Board 

accepted a final report in January 1990. The results have been used to estimate the lake 

volume and provide relationships between lake stage, volume, and surface area. The 

lake was shown to be relatively flat, with some evidence of scouring channels, 

particularly in the southwest. Bathymetric survey data are being used in analysis of 

water circulation patterns in the lake for siting of marsh flow-way intake structures and 

for design of littoral zone restoration plantings. The mean lake depth at 20 m (66 ft) 

(msl) is 1.46 m (4.81 ft). 

Report

Danek, L.J., and M.S. Tomlinson. 1989. Bathymetric analysis of Lake Apopka. Special Publication 

SJ89-SP6. Palatka, Fla.: St. Johns River Water Management District. 
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PROJECT (LA-4-107-D): FISHERY

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; low recreational and aesthetic 

values 

PROJECT OBJECTIVE: To obtain information on game and rough-fish populations in 

Lake Apopka 

SCOPE OF WORK: Phase I—To collect data from electrofishing and blocknet studies 

prior to restoration efforts in the lake. Phase II—To determine any changes in the fish 

community resulting from ongoing restoration efforts; to collect data in the same 

manner and locations to allow comparisons with the Phase I project; to add new 

sampling sites in recently planted littoral zone areas; and to include electrofishing, 

blocknets, gill nets, and otter trawl sampling methods on adult and subadult game fish. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will provide 

ongoing information on the effects of efforts to improve fisheries and fisheries habitat in 

Lake Apopka. 

SUMMARY AND STATUS: Phase I—This cooperative (non-contract) effort with FWC 

(formerly the Florida Game and Fresh Water Fish Commission) to monitor fish stocks 

began in 1988 and was implemented on a cooperative and no-cost basis. The project 

terminated at the end of the 1990–91 fiscal year. FWC has provided SJRWMD with a 

final report on the three-year effort. Littoral blocknet sample results show a 22% relative 

abundance for the four primary Centrarchid gamefish species in the 1973–76 period, 

and a 39% relative abundance for these species in the 1989–91 period. Average littoralzone biomass of these species increased from 125 kg/ha for the 1973–76 period to 240 

kg/ha for the 1988–91 period. Black crappie was the only gamefish species to make a 

substantial contribution to the pelagic fish population of Lake Apopka; however, there 

was no significant difference in the percent relative abundance of this species between 

the two time periods. Although the total littoral zone gamefish biomass of Lake Apopka 

has apparently increased since 1976, the biomass of the most important recreational 

species, largemouth bass, remains low when compared to other eutrophic lakes in the 

region (17.5 kg/ha for Lake Apopka, 25.7 kg/ha for nearby Lake Griffin for the 1989–91 

period). The cause for the apparent gamefish population increase in Lake Apopka is 
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116 

unknown; however, water quality improvement and germination of emergent littoral 

vegetation during the 1981 low-water period are suspected causes. 

Phase II—This contractual project with FWC is designed to determine any changes in 

the gamefish community resulting from ongoing restoration efforts. Beginning in 

November 1996 and continuing through November 1997, adult and subadult samples 

were collected from the Lake Apopka shoreline zone. When compared with blocknet 

samples taken from 1989 to 1991, average total biomass and numbers of harvestablesize sport fish were lower or unchanged in 1997 samples. 

Beginning in 1981, a major decline was observed in juvenile alligators on Lake Apopka. 

USFWS, UF, and FWC researchers identified reproductive failure in alligator and turtle 

populations in the lake and found a possible link to DDE and other organic 

contaminants. Such compounds are found in low concentrations in Lake Apopka 

sediments. However, recent work by Gross et al. (1998) does not support the hypothesis 

that DDT or DDE are linked to alligator clutch viability. Also, two distinct populations 

of alligators have been detected. Clutches from south Lake Apopka had higher nested 

egg numbers, hatched egg numbers, neonatal survivor numbers, viability rate, hatch 

rate, and production rate than clutches from north Lake Apopka. According to Rice and 

Percival (1996), an increasing trend in the juvenile population and in clutch viability has 

occurred on Lake Apopka since 1989. They suggest that the system may be recovering 

or that the juvenile animals, though currently surviving, might not reproduce or 

survive in the future. 

A National Institute of Environmental Health Sciences grant, based upon EPA 

Superfund resources, was awarded to a group of researchers centered at UF to study 

environmental effects of organic toxins in Lake Apopka and elsewhere. This research 

has indicated that contaminant-induced endocrine disruption occurs in wildlife, 

specifically fish and alligators, and several effective biomarkers have been identified to 

study these effects. 

Crain et al. (1999) found that embryonic exposure to 2,4-D or atrazine did not cause 

significant alterations in gonadal structure or hepatic steroidogenic enzyme activity of 

hatchling American alligators. The results indicate that these herbicides alone are not 

responsible for the gonadal abnormalities previously reported for juvenile alligators 

from Lake Apopka. Since structural assessment (i.e., histological analysis) alone may be 

insufficient to detect subtle endocrine alterations, the function (i.e., steroidogenic 

enzyme activity) should also be analyzed. Also, they suggested examining the effects of 

other endocrine-disrupting contaminants that are present in Lake Apopka. 
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Further assessments and analyses of the fish community or of other wildlife 

populations in Lake Apopka during the implementation of the restoration program are 

accomplished under Project LA-6-803-S: Restoration Monitoring and Analysis. 

Reports

Benton, J., D. Douglas, and L. Prevatt. 1991. Oklawaha Basin fisheries investigations: Study XII. 

Lake Apopka fisheries studies. Florida Game and Fresh Water Fish Commission completion 

report. Wallop-Breaux project F-30-18. Eustis, Fla. 

Crain, D.A., I.D. Spiteri, and L.J. Guillette Jr. 1999. The functional and structural observations of 

the neonatal reproductive system of alligators exposed in ovo to atrazine, 2,4-D or estradiol. 

Toxicology and Industrial Health 15:180–185. 

Gallagher, E.P., and K.M. Sheehy. 2000. Altered glutathione S-transferase catalytic activities in 

female brown bullheads from a contaminated central Florida lake. Marine Environ. Res. 

50:399–403. 

Gallagher, E.P., T.S. Gross, and K.M. Sheehy. 2001. Decreased glutathione S-transferase 

expression and activity and altered sex steroids in Lake Apopka brown bullheads (Ameiurus 

nebulosus). Aquat. Toxicol. 55:223–237. 

Gross, T.S., and N. Kernaghan. 2002. Endocrine disrupting effects of chlorinated hydrocarbons in 

fish and alligators in central Florida. SIS1998. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_Projects]. 

Florida Caribbean Science Center, Gainesville. 

Gross, T.S., and M. Sepulveda. 2002. Chlorinated hydrocarbons and developmental toxicity in 

wildlife. SIS4292. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_Projects]. 

Florida Caribbean Science Center, Gainesville. 

Gross, T.S., and J. Wiebe. 2002. Immuno-toxicity and endocrine disruption in Lake Apopka 

alligator neonates. SIS2002. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_Projects]. 

Florida Caribbean Science Center, Gainesville. 

Gross, T.S., D. Giroux, D.A. Gross, and H.F. Percival. 1998. Lake Apopka revisited: An 

evaluation of environmental contaminants and associated reproductive anomalies in 

alligators. In Proceedings of the Seventh Annual Southeast Lakes Management Conference, April 

15–18, 1998, Orlando, Fla. 
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Gross, T.S., R. Roberts, J.M. de Oca, and H.F. Percival. In preparation. Sex reversal in freshwater 

turtles as a response to estrogenic environmental contaminants. University of Florida, 

Gainesville. 

Gross, T.S., M. Sepulveda, S.D. Ruessler, J.N. Wiebe, and C.M. Wieser. 2002. Microcosm and 

mesocosms evaluation of the bioaccumulation of chlorinated pesticides in the North Shore 

Restoration Areas. SIS4944. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_Projects]. 

Florida Caribbean Science Center, Gainesville, Fla. 

Gu, B., C.L. Schelske, and M.V. Hoyer. 1997. Intrapopulation feeding diversity in blue tilapia: 

Evidence from stable-isotope analyses. Ecology 78:2263–2266. 

Guillette, L.J., Jr. 1995. Endocrine disrupting environmental contaminants and developmental 

abnormalities in embryos. Human and Ecological Risk Assessment 1(2):25–36. 

Guillette, L.J., Jr., and D.A. Crain. 1996. Endocrine-disrupting contaminants and reproductive 

abnormalities in reptiles. Comments Toxicology 5(4-5):381–399. 

Guillette, L.J., Jr., J.W. Brock, A.A. Rooney, and A.R. Woodward. 1999. Serum concentrations of 

various environmental contaminants and their relationship to sex steroid concentrations and 

phallus size in juvenile American alligators. Arch. Environ. Contam. Toxicol. 36:447–455. 

Guillette, L.J., Jr., D.A. Crain, A.A. Rooney, and D.B. Pickford. 1995. Organization versus 

activation: The role of endocrine-disrupting contaminants during embryonic development 

in wildlife. Environ. Health Perspect. 103(7):157–164. 

Guillette, L.J., Jr., T.S. Gross, D.A. Gross, A.A. Rooney, and H.F. Percival. 1995. Gonadal 

steroidogenesis in vitro from juvenile alligators obtained from contaminated or control lakes. 

Environ. Health Perspect. 103(Suppl.4):31–36. 

Guillette, L.J., Jr., D.B. Pickford, D.A. Crain, A.A. Rooney, and H.F. Percival. 1995. Reduction in 

penis size and plasma testosterone concentrations in juvenile alligators living in a 

contaminated environment. Gen. Comp. Endocrinol. 101:32–42. 

Guillette, L.J., Jr., T.S. Gross, G.R. Masson, J.M. Matter, H.F. Percival, and A.R. Woodward. 1994. 

Development abnormalities of the gonad and abnormal sex hormone concentrations in 

juvenile alligators from contaminated and control lakes in Florida. Environ. Health Perspect. 

102:680–688. 

Johnson, W.E., and J.E. Crumpton. 1998. Lake Apopka fish population assessment. Final report for 

Contract 97W121 for St. Johns River Water Management District, Palatka, Fla. Florida Game 

and Fresh Water Fish Commission, Eustis, Fla. 
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Percival, H.G. 1994. Lake Apopka’s alligators: The end of the ruling reptiles? Lake Reserv. 

Manage. 9(2):102. 

Rice, K.G., and H.F. Percival, eds. 1996. Effects of environmental contaminants on the 

demographics and reproduction of Lake Apopka’s alligators and other taxa. Technical 

report 53. Fla. Coop. Fish and Wildlife Res. Unit, University of Florida, Gainesville. 

Rotstein, D.S., T.R. Schoeb, L.M. Davis, T.C. Glenn, B.S. Arnold, and T.S. Gross. 2002. Detection 

by microsatellite analysis of early embryonic mortality in an alligator population in Florida. 

J. Wildl. Dis. 38(1):160–165. 

Semenza, J.C., P.E. Tolbert, C.H. Rubin, L.J. Guillette Jr., and R.J. Jackson. 1997. Reproductive 

toxins and alligator abnormalities at Lake Apopka, Florida. Environ. Health Perspect.

105:1030–1032. 

Willingham, E., and D. Crews. 1999. Sex reversal effects of environmentally relevant xenobiotic 

concentrations on the red-eared slider turtle, a species with temperature-dependent sex 

determination. Gen. Comp. Endocrinol. 113(3):429–435. 

PROJECT (LA-1-108-D): SEISMIC REFLECTION PROFILING

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To examine subsurface geology across Lake Apopka and assess 

the nature of the confining layers between the lake and the Floridan aquifer 

SCOPE OF WORK: Construct approximately 70 km (44 miles) of continuous seismic 

reflection profiles. Use existing well data to interpret the profiles. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project provides data 

to quantify potential subsurface water exchange which would affect the water budget 

for Lake Apopka. 

SUMMARY AND STATUS: A final report was submitted to SJRWMD in August 1988 

by the University of South Florida. The report concludes that significant water exchange 

between Lake Apopka and the underlying Floridan aquifer is unlikely. No further work 

is planned for this project at present. 
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Report

Locker, S.D., G.R. Brooks, and L.J. Doyle. 1988. Results of a seismic reflection investigation and 

hydrogeologic implications for Lake Apopka, Florida. Special Publication SJ88-SP5. Palatka, Fla.: 

St. Johns River Water Management District. 

PROJECT (LA-4-109-D): HYDRODYNAMIC SURVEY

PROGRAM: Diagnostic 

PRIORITY: Completed 

ISSUE CATEGORY: Lack of fish and wildlife habitat 

PROJECT OBJECTIVE: To characterize dominant seasonal meteorological conditions at 

Lake Apopka; to model water current velocities and directions in Lake Apopka and 

describe how water movements vary with meteorological conditions; to estimate 

mixing dynamics of discharge waters from a fully implemented marsh flow-way; and to 

evaluate potential solutions to “short circuiting” of filtered water from the marsh 

discharge point to the intake point 

SCOPE OF WORK: Evaluate the historical record of wind speed and direction in Lake 

Apopka and quantify the dominant seasonal characteristics. Model the velocities and 

directions of water currents in Lake Apopka to determine the potential for “short 

circuiting” of discharge water from the full-scale marsh flow-way and to select suitable 

areas for littoral zone restoration. Evaluate various flow-way designs and operational 

levels to quantify the degree of short-circuiting. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project provides 

information necessary to design the full-scale marsh and to determine areas of Lake 

Apopka suitable for littoral zone restoration. These projects provide water quality 

improvements and restoration of natural systems. 

SUMMARY: The project was initiated in May 1992. SJRWMD provided summarized 

historical wind velocity data and current meteorological data. The contractor, UF, 

produced wind velocity information from SJRWMD data and compared this 

information to regional information to evaluate data quality. Meteorological and 

hydrodynamic measurements were made over a five-week period for initial calibration 

of the hydrodynamic model. A draft model was completed and installed on SJRWMD 

computers. A draft software documentation report was received with the model. The 

first phase of the work was extended in an effort to perform a dye study under wind 
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conditions that had not occurred in the first part of the winter. The dye study, designed 

to assess the extent of mixing of marsh discharge water from the Apopka-Beauclair 

Canal with lake water, was completed. Results from fluorometer readings, aerial 

photographs, and analysis of dye samples all revealed consistent dispersion patterns of 

the discharge water: an initial southward movement and a subsequent eastward 

movement of the discharge plume. 

Phase II was initiated in May 1993. Analysis of Phase I work indicated a potential for 

“short circuiting” of the marsh outflow to the inflow and the need for additional 

bathymetry work in the northwest area of the lake. The necessary contract amendments 

and other changes to specific tasks made as a result of Phase I findings were approved 

in the fourth quarter of 1993. The contract termination date was extended to December 

1994. The final report in five volumes was accepted after revision and the contract was 

terminated. 

Reports

Sheng, P., and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake Apopka. Vol. II, 

Bathymetric surveys of the northwest section of Lake Apopka, and Vol. III, Lake Apopka 1992 field 

data report. Final reports prepared for St. Johns River Water Management District, Palatka, Fla. 

University of Florida, Gainesville. 

Sheng, P., X. Meng, and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake Apopka. 

Vol. I, Analysis of wind data from Lake Apopka and Orlando airport. Final report prepared for St. 

Johns River Water Management District, Palatka, Fla. University of Florida, Gainesville. 

Sheng, P., S. Schofield, X. Meng, and K. Ellins. 1994. Assessment of hydrodynamic conditions in Lake 

Apopka. Vol. IV, Dispersion of discharge water from the Apopka-Beauclair Canal into Lake Apopka, 

and Vol. V, A three-dimensional hydrodynamic numerical model of wind-driven circulation in Lake 

Apopka (LAHM3D): Theory, Model documentation, user’s manual and model simulation. Final 

reports prepared for St. Johns River Water Management District, Palatka, Fla. University of 

Florida, Gainesville. 

PROJECT (LA-4-201-F): WATER HYACINTH DEMONSTRATION

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 
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PROJECT OBJECTIVE: To test the feasibility of using water hyacinths to remove 

nutrients from Lake Apopka 

SCOPE OF WORK: Utilize a series of small enclosures in Lake Apopka to determine the 

rate of growth and growth-affecting factors for water hyacinths cultured in Lake 

Apopka. Stock enclosures with hyacinths at specific densities and monitor until 

maximum density is reached or for a 90-day period, whichever occurs first. At the end 

of the test period, harvest hyacinths and record fresh weight biomass. Obtain water 

quality samples adjacent to the enclosures and analyze for nutrients. Analyze plant 

tissue from these samples for N and P levels. Utilize larger enclosures in a small, 

hypereutrophic lake to test hyacinth growth rates and the depletion of N, P, and organic 

carbon in the water column and sediments. Establish a small hyacinth farming 

operation in the experimental lake and determine the cost/unit weight of water column 

and sediment nutrient removal from the results of the farming operation. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will evaluate 

hyacinth culture as a potential method of reducing nutrient levels in Lake Apopka as 

directed by the 1985 Lake Apopka Restoration Act (Appendix A). 

SUMMARY: The Round Lake water hyacinth demonstration farm was to operate for 24 

months from May 1989. However, serious drought conditions resulted in water levels 

so low that farming operations had to be terminated in September 1990, after 

approximately 17 months. During operation of the hyacinth farm, water, sediment, 

pesticide, and plant samples were collected and analyzed. The water hyacinth 

enclosures in Lake Apopka were stocked with water hyacinths in April 1989. Water, 

sediment, pesticide, and plant samples were collected and analyzed as scheduled for a 

24-month period. 

The project was restructured in February 1991 to reflect the reductions in scope and 

budget necessitated by prematurely terminating Round Lake operations. The project 

was amended in September 1991 to add a two-month experiment. In this experiment, 

nutrient diffusion rates from the sediments and the nutrient and detritus sedimentation 

rates were measured in three isolated enclosures stocked with varying concentrations of 

water hyacinths and in two controls without hyacinths. One control enclosure was 

covered with five layers of shade cloth to simulate light conditions underneath a dense 

water hyacinth mat. 

Three semi-annual progress reports and a draft final report were received describing 

the Round Lake hyacinth farm and studies in the Lake Apopka enclosures. The contract 

was amended to an October 31, 1993, termination date and a June 30, 1993, draft report 

deadline. After a review of the draft reports, the contract was extended to August 1994. 
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A final agreement with the contractor terminated the work and further revision of the 

final products. 

PROJECT (LA-4-202-F): PHOSPHORUS INACTIVATION/PRECIPITATION

PROGRAM: Feasibility Program 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To evaluate the feasibility of using alum as a precipitant to trap 

nutrients in an insoluble form 

SCOPE OF WORK: Perform a literature survey to determine the strengths and 

weaknesses of chemical treatment methods and likelihood of their successful 

application to Lake Apopka. Conduct laboratory tests of alum and other precipitants 

using Lake Apopka water and sediments. Determine the economic costs of treating 

different size areas of the lake. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project was 

formulated to evaluate alum as a potential chemical treatment method to reduce 

nutrient levels in Lake Apopka. 

SUMMARY AND STATUS: Phase I was completed and a final report submitted to 

SJRWMD in September 1987. The report discourages alum use as the sole restoration 

technique in Lake Apopka. 

Report

Baird, R.A., and J.M. Bateman. 1987. A preliminary assessment of phosphorus precipitationinactivation as a restoration technique in Lake Apopka. Special Publication SJ87-SP5. Palatka, 

Fla.: St. Johns River Water Management District. 

PROJECT (LA-4-204-F): SEDIMENT RECYCLING

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 
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PROJECT OBJECTIVE: To determine feasibility of sediment removal and reuse for the 

restoration of Lake Apopka 

SCOPE OF WORK: Investigate the existing scientific literature for case studies of other 

systems restored by sediment removal. Use those case studies in conjunction with 

extant data for Lake Apopka to assess the effects of sediment removal on surface 

chemistry of the lake. Evaluate the market potential for recovered sediment and 

develop a cost/benefit analysis for using sediment removal to restore Lake Apopka. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: Flocculent organic 

sediments represent a significant problem in Lake Apopka. Internal nutrient loading 

and altered bottom conditions associated with these sediments may require their 

removal or consolidation in restoration of the lake. This project was formulated to 

determine the feasibility of dredging for sediment removal. 

SUMMARY: A final report was prepared by KBN Engineering and Applied Sciences in 

November 1988 for Governing Board acceptance in January 1989. Dredging was found 

to have potential as a restoration technique, although questions regarding redistribution 

of flocculent sediments during the long dredging period and nutrient release from 

exposed peat layers would need to be addressed. Removal of four feet of sediments 

would require five 24-in. dredges operating continuously for six years at an estimated 

cost of $868,800,000. This cost estimate includes shore facilities for dewatering dredged 

sediment and for treatment of runoff water, but does not include the cost of land for 

these facilities. Sediment reuse offers only limited ability to recover these costs; an 

absolute upper limit for savings is $97,400,000. Dredging is presently not considered 

cost-effective for a full-scale restoration. 

Report

Pollman, C.D., D.A. Graetz, F.V. Ramsey, K.R. Reddy, and T.J. Sullivan. 1988. Feasibility of 

sediment removal and reuse for the restoration of Lake Apopka. Special Publication SJ88-SP10. 

Palatka, Fla.: St. Johns River Water Management District. 

PROJECT (LA-4-205-F): MICROBIAL DECOMPOSITION

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORY: Poor water quality and flocculent sediments 
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PROJECT OBJECTIVE: To evaluate ways of stimulating natural processes which reduce 

the bulk of lake sediments 

SCOPE OF WORK: Compile and evaluate available information regarding in situ

sediment decomposition, provide a preliminary assessment of the feasibility of the 

technology, and present recommendations on further research and assessment 

activities. Investigate the following four techniques for sediment decomposition: 

microbial inoculation, nitrate application, hydrogen peroxide addition, and ozonation. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project provides an 

evaluation of a potential methodology to reduce the bulk of flocculent organic 

sediments in Lake Apopka. 

SUMMARY AND STATUS: Phase I was completed and a final report prepared in 

December 1988 for Governing Board acceptance in February 1989. The four specific 

techniques evaluated were microbial inoculation, nitrate addition to stimulate 

denitrification, hydrogen peroxide application, and ozonation. The theoretical 

framework for microbial inoculation is highly controversial and is not supported by 

experimental data. Chemical techniques (hydrogen peroxide, ozonation) are effective in 

oxidizing sediments but create severe water quality problems in overlying waters. 

Nitrate application has a demonstrated ability to oxidize organic sediments and reduce 

phosphorus recycling, but estimated costs for treatment of Lake Apopka are high ($790 

million). Therefore, this technique is not presently considered cost-effective. 

Report

Gremillion, P.T., and C.E. Mericas. 1988. A literature review and feasibility analysis assessing 

microbial decomposition as a technique for restoring Lake Apopka. Special Publication SJ88-SP11. 

Palatka, Fla.: St. Johns River Water Management District. 

PROJECT (LA-4-206-F): ICHTHYOFAUNAL RECONSTRUCTION (I, II) 

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments 
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PROJECT OBJECTIVE: Phase I—To compile a literature review and annotated 

bibliography on biomanipulation as a lake restoration technique. Phase II—To evaluate 

the potential for use of exotic fish species to aid in the restoration of Lake Apopka by 

consumption of excess production of algae 

SCOPE OF WORK: Phase I—Prepare literature review with annotated bibliography on 

the subject of biomanipulation as a potential restoration technique, including 

information on the use of exotic species for algal biomass control. Identify candidate 

fish species for introduction. Design pilot studies to determine the applicability of the 

proposed introductions to manipulation of the algal biomass of Lake Apopka. Phase 

II—Use bighead carp (Hypophthalmichthys nobilis) in replicated pond studies to 

determine if this exotic fish is able to cause a reduction in nutrients and/or changes in 

the algal community. Use four ponds as experimental treatments and two ponds as 

controls. Use two stocking rates in the experimental ponds. Collect data on fish length, 

weight, and food habits. Sample water column to determine water quality and 

phytoplankton species composition. This project will test the use of bighead carp to 

consume algal biomass directly or to cause a positive change in the algal structure of the 

lake. 

SUMMARY: Phase I—The literature review report was prepared in November 1988 for 

Governing Board acceptance in January 1989. No clear judgment could be made 

concerning the past success of this methodology or the expected effects of fish 

biomanipulation in Lake Apopka. 

Phase II—This pilot project used experimental ponds adjacent to Lake Apopka which 

were either not stocked with fish or stocked with bighead carp to low density or high 

density to measure effects of fish on water quality and phytoplankton density and 

community structure. Ponds were stocked with fish in the spring of 1990, and the 

experiment proceeded with data collection until September 1990. A final report on this 

work was completed in January 1992. Results show that there were no significant 

differences in water quality parameters between control ponds (not stocked) and ponds 

stocked with fish. Algal density or community composition did not change significantly 

in the ponds stocked with fish; however, there was some measurable change in the 

blue-green/green algal ratio in those ponds stocked with fish. The fish biomass level 

projected as necessary to cause significant changes in the algal community and in water 

quality was not achieved in the experimental ponds due to slow growth and high 

mortality of the stocked fish. 
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Reports

Continental Shelf Associates, Inc. 1988. Literature review and feasibility analysis report on 

ichthyofaunal reconstruction as a technique for restoring Lake Apopka. Special Publication SJ88-

SP6. Palatka, Fla.: St. Johns River Water Management District. 

Shireman, J.V., and K.K. Opuszynski. 1992. Ichthyofaunal reconstruction for the management of 

phytoplankton. Special Publication SJ92-SP4. Palatka, Fla.: St. Johns River Water Management 

District. 

PROJECT (LA-4-207-F): TROPHIC STRUCTURE MANIPULATION (I, II, III) 

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments 

PROJECT OBJECTIVE: Phase I—To provide baseline data on the role of rough fish in 

plankton and nutrient dynamics in enclosures. Phase II—To determine whether harvest 

of rough fish (primarily gizzard shad) can improve water quality through effects on the 

food web or through export of in-lake nutrients. Phase III—To test standard harvesting 

gear for large-scale rough-fish removal in Lake Apopka and to determine the feasibility 

of using harvested rough fish (primarily gizzard shad) as marketable products to offset 

the cost of fish removal 

SCOPE OF WORK: Phase I—Perform short-term enclosure studies in Lake Apopka. 

Place rough fish in experimental enclosures and determine whether nutrients and 

plankton dynamics over short time periods are different from control enclosures with 

no fish. 

Phase II—Select a small hypereutrophic lake representative of Lake Apopka as the site 

for this pilot study. Collect baseline data for up to one year from this lake on plankton 

community structure, biomass, and production; nutrient dynamics and water quality; 

sediment dynamics; and fish community dynamics. During the second segment of the 

study, remove rough fish (gizzard shad) from the lake by haul seine. Monitor the lake 

system during the third segment of the project to detect changes in lake trophic 

structure or nutrient recycling following rough-fish removal efforts. 
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Phase III—Test standard harvesting gear in Lake Apopka: haul seine, gill net, and 

pound net. Record catches to the species level and collect biological statistics. 

Investigate potential markets for harvested rough fish in a contracted marketing study. 

Attempt to develop marketable products from the harvested fish. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: Rough fish constitute the 

majority of fish biomass in hypereutrophic lakes such as Lake Apopka. Experimental 

evidence suggests that these fish may be directly linked to blue-green algal dominance 

and rapid nutrient recycling. This project will assess the effects of removal of gizzard 

shad on lake trophic structure and nutrient recycling. 

SUMMARY: Phase I—The principal investigator was Dr. Tom Crisman, UF. A final 

report was delivered to SJRWMD in April 1988. The experiment provided evidence that 

the effects of shad and tilapia on plankton community metabolism differed greatly. 

Compared to tilapia, the presence of shad caused wider fluctuations in daily dissolved 

oxygen concentrations, which may stress or kill desirable game fish. There are also 

indications that the grazing activities of shad promote mineralization and accelerate 

phosphorus recycling. 

Phase II—This pilot experiment contrasted water quality, zooplankton, phytoplankton, 

and fish in an experimental lake subject to rough-fish removal (Lake Denham) with 

conditions in control lakes Beauclair and Apopka. Sampling to document initial 

conditions in Lakes Denham, Beauclair, and Apopka was initiated in 1989. Rough fish 

were removed from Lake Denham by haul seine from January to April 1990, in May 

1991, and again in June 1992. The adult gizzard shad biomass was reduced by about 

85% by the haul-seine efforts. 

Monitoring of post-manipulation conditions is ongoing (see Project LA-6-803-S, 

Restoration Monitoring and Analysis). Data indicate some of the classical “trophic 

cascade” effects in Lake Denham following fish removal. In experimental gill net sets 

taken quarterly, medium-to-large gizzard shad make up the majority of the catch. 

Young-of-the-year shad are still in low numbers. Water quality parameters, 

phytoplankton abundance and composition, and zooplankton abundance and 

composition showed large changes in the experimental lake. Some changes were 

observed in the control lakes as well, which emphasizes the need for rigorous statistical 

tests of the final data set. Following removal of a fish barrier at the downstream end of 

the lake, gizzard shad re-entered Lake Denham. A decline in water quality followed the 

re-establishment of shad in the lake; however, lake conditions remain better than for the 

period prior to fish removal. 
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Phase III—Trial haul-seining operations were conducted in Lake Apopka in April and 

May 1990. The large size, shallow water depth, and extensive flocculent sediments of 

the lake were detrimental to the seining operation, and this technique was not an 

efficient or cost-effective method for fish removal in Lake Apopka. SJRWMD was 

unable to contract to test pound nets; it appears that this fishing technique is no longer 

used in Florida. Modified purse gill nets and trawls were not successful for harvesting 

gizzard shad in Lake Apopka; however, standard gill nets were found to be an efficient 

and cost-effective harvest method for large-scale rough-fish removal (see Project LA-3-

302-M, Rough Fish Harvesting). 

A product development and marketing survey project for gizzard shad was contracted 

with FDEP in January 1990, and a final report on this work was accepted in February 

1991. Current market demand for gizzard shad from Lake Apopka is low, and attempts 

to develop new markets for products from the fish have not been successful. Because of 

the weak market position, the harvesting of gizzard shad from the lake is not yet selfsustaining. 

Reports 

Benton, J., D. Douglas, and D. Watson. 1994. Ichthyofaunal studies as part of the trophic structure 

manipulation studies. Final report for Segments I–III. Florida Game and Fresh Water Fish 

Commission, Fisheries Research Laboratory. Special Publication SJ94-SP5. Palatka, Fla.: St. 

Johns River Water Management District. 

Crisman, T.L., and J. Beaver. 1988. Phase I—Final report: Lake Apopka trophic structure. St. 

Johns River Water Management District, Palatka, Fla. 

Godwin, W.F. 1989. Trophic structure manipulation project, Phase II, quality assurance project 

plan for the Lake Apopka restoration project. St. Johns River Water Management District, 

Palatka, Fla. 

Godwin, W., S.G. Coyne, and E.A. Gisondi. 1993. An evaluation of rough-fish harvesting as a 

restoration technique for Lake Apopka. Technical memorandum 3. St. Johns River Water 

Management District, Palatka, Fla. 

Thomas, C.C. 1991. Rough fish market survey final report. Special Publication SJ91-SP2. Palatka, 

Fla.: St. Johns River Water Management District. 

PROJECT (LA-4-208-F): DRAWDOWN AND LAKE LEVEL FLUCTUATION

PROGRAM: Feasibility 
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130 

PRIORITY: 1 

ISSUE CATEGORIES: Low recreational and aesthetic values; lack of fish and wildlife 

habitat; poor water quality and flocculent sediments 

PROJECT OBJECTIVE: To evaluate the feasibility of using drawdown or greater 

fluctuation in water levels to consolidate littoral sediments and stimulate aquatic 

vegetation to improve fish and wildlife habitat 

SCOPE OF WORK: Phase I—Evaluate the experience base and the scientific literature to 

determine documented ecological effects of lake drawdowns or enhanced fluctuation. 

Phase II—Examine the effects of partial drawdown of Newnans Lake with regard to (1) 

flushing of organic matter, nitrogen, and phosphorus in discharge from the lake, (2) 

effects of exposing littoral sediment to air, and (3) net change of organics, nitrogen, and 

phosphorus in profundal and littoral sediments. 

Phase III—Produce a basin hydrologic model that permits long-term simulation of lake 

stages under various water regulation scenarios and climate patterns. Collect data on 

wetland plant communities along elevational transects. Determine elevations of manmade structures. Examine existing and proposed water regulation schedules for 

environmental effects and socioeconomic consequences. Recommend new regulation 

schedules for rule changes. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: Stabilized water levels 

have been cited as a factor in the degradation of Lake Apopka. This project will 

determine the potential for improvement in environmental conditions through 

modification of lake regulation schedules. 

SUMMARY AND STATUS: Phase I—Dames and Moore was contracted in October 1989 

to provide a comprehensive study of the ecological effects of drawdown, and their final 

report was completed in December 1990. Generally, drawdowns improve shoreline 

vegetation and the associated macroinvertebrate populations, increase population sizes 

of some species of fish, and may consolidate lake sediments in exposed areas. However, 

these benefits last only 2–7 years; drawdowns must be repeated on a recurring basis. 

Drawdowns do not improve water quality, and they can lead to significant sediment 

and nutrient loading to downstream waters which receive the discharge. In Lake 

Apopka, a drawdown of 1 m (3 ft) would expose only 8.6% (1,070 ha or 2,640 ac) of lake 

bottom. However, due to the wicking action of the sediments, only about 240 ha (600 ac) 

(1.9%) would probably be consolidated. A 1-m drawdown on Lake Apopka would 

require discharging about 70% of the lake volume to the downstream chain of lakes. 
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This discharge water would have high concentrations of sediments and nutrients and 

would therefore be detrimental to downstream lakes. Drawdown as a restoration 

technique for Lake Apopka also was evaluated by Fulton (1998). 

Phase II—A contractual study with UF was initiated in March 1989 to measure the 

water quality and sediment effects of a three-month drawdown of hypereutrophic 

Newnans Lake. The final report in two parts was approved in September 1992 and is 

pertinent to lakes where drawdowns are considered for the removal of organic matter 

and nutrients and for sediment consolidation and oxidation. Net oxidation of exposed 

lake bottom sediments was not demonstrated to result from drawdown. Consolidation 

of exposed lake bottom sediments was an observed benefit, however. This study 

demonstrated the importance of sediment redistribution during drawdowns and that 

flocculent sediments were eroded from the littoral zone toward deeper areas of the lake. 

Moderate removal of organic matter and nutrients from the lake by flushing during 

drawdown also was documented. The timing of drawdowns to coincide with periods of 

high winds to enhance resuspension and subsequent removal of flocculent lake 

sediments was an important recommendation made in this study. 

Phase III—In-house work to formulate and evaluate alternative enhanced lake level 

fluctuation schedules continues. The long-term goal of this project is to develop a 

schedule that allows lake level fluctuations that more closely follow seasonal and longterm rainfall patterns without impacting flood control efforts. Vegetative analyses along 

surveyed transects in Lake Apopka and the other upper Ocklawaha River lakes to 

determine elevation gradients of existing wetlands have been completed. Engineering 

components—including surveys of elevations of docks, canals, and bulkheads to permit 

a full economic-impact analysis of proposed schedules and work to refine the basin 

hydrology model—are ongoing. Preliminary recommendations for enhanced lake-level 

fluctuation were prepared and discussed in several meetings of the Ocklawaha River 

Basin Technical Advisory Group and in public workshops. More recently, original 

proposals made several years ago have been re-evaluated to better understand the 

potential problems that would be caused by lower low-water levels and higher highwater levels in Lake Apopka and the Harris Chain. Efforts to change the way lake levels 

are managed reached a turning point in 2001 with the determination that new schedules 

should not increase the frequency of high water levels. 

Consideration of regulation schedules will continue, in part, through a new project 

conducted by the U.S. Army Corps of Engineers and SJRWMD. The reconnaissance 

phase of the Upper Ocklawaha River Basin Restudy project began in 2002. If this 

reconnaissance study leads to the next (feasibility) phase, one of the goals will be to find 

and evaluate operational modifications that could enhance environmental restoration 

benefits in the basin. A major component may be further consideration of a new 
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regulation schedule for Lake Apopka that would follow rainfall more closely and 

restore higher periodic water levels in Lake Apopka and its associated wetlands. 

Reports 

Fulton, R.S. 1998. Evaluation of drawdown as a restoration technique for Lake Apopka. 

Technical memorandum 27. St. Johns River Water Management District, Palatka, Fla. 

Gottgens, J.F., and T.L. Crisman. 1992. Newnans Lake, Florida: Removal of particulate organic matter 

and nutrients using a short-term drawdown (Phase I). Special Publication SJ92-SP23. Palatka, 

Fla.: St. Johns River Water Management District. 

———. 1992. Sediments of Newnans Lake: Characteristics and patterns of redistribution following a 

short-term drawdown (Phase II). Special Publication SJ92-SP24. Palatka, Fla.: St. Johns River 

Water Management District. 

Greening, H., and S. Doyon. 1990. Environmental and ecological effects of drawdown and enhanced 

fluctuation for Lake Apopka, Florida. Special Publication SJ90-SP9. Palatka, Fla.: St. Johns River 

Water Management District. 

Drawdown and Lake Level Fluctuation 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

U.S. Army Corps of Engineers 

restudy X X X X X X X X X X X X X X X X

PROJECT (LA-4-209-F): SOCIOECONOMIC ASSESSMENT AND 

METHODOLOGY

PROGRAM: Feasibility 

PRIORITY: Completed 

ISSUE CATEGORY: Lack of fish and wildlife habitat 

PROJECT OBJECTIVE: To develop methodology to assess the economic value of 

recreational and commercial uses of Lake Apopka, predict the economic benefit of lake 

restoration, and assess the impact of a total muck farm buyout on the local economy 

SCOPE OF WORK: Develop an evaluation procedure for performing a socioeconomic 

assessment of the Lake Apopka Basin. Incorporate the procedure into computer 
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software to be used by SJRWMD. Perform a socioeconomic assessment of the basin, 

including the potential economic losses and benefits of the purchase of 5,670 ha 

(14,000 ac) of muck farms in Lake and Orange counties, plus possible mitigation 

measures to offset employment losses. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: The degradation of Lake 

Apopka has resulted in greatly reduced recreational and aesthetic values of the water 

body. This project will provide factual information on the present values of the lake and 

the potential values of the lake in a restored condition. 

STATUS: A report was submitted in July 1989 by UF which developed methodology 

and predicted the economic benefit of lake restoration (Heaney et al. 1989). The 

estimated net revenue from the muck farms was compared to losses from decreased 

recreational values, lowered environmental quality to the general public, and decline in 

property values to the riparian owners. 

The 1996 Legislature determined that it was in the public interest to pursue the 

purchase and marsh restoration of all the muck farms in the Lake Apopka Basin. One 

consequence of such an action would be the loss of the farm business income and jobs. 

An economic impact analysis of the cessation of muck farming in the Lake Apopka 

Basin was performed by Apogee Research. A final report was provided to SJRWMD in 

December 1996. The report identified $110 million of annual economic losses incurred 

through such an action, roughly divided into direct sales losses and loss of income. A 

preliminary partial analysis of restoration benefits was estimated at $30 million 

annually. Additional research would be necessary to identify and quantify all benefits 

resulting from a farm buyout, such as increased land values and increased recreation in 

downstream lakes. 

Reports 

Apogee Research, Inc. 1996. Lake Apopka economic analysis. Final report for Contract 96G307. 

Submitted to St. Johns River Water Management District, Palatka, Fla. Bethesda, Md. 

Heaney, J.P., T.D. Feather, and M. Shafer. 1989. Development of a socio-economic assessment 

methodology with applications to the Lake Apopka Basin. Special Publication SJ89-SP5. Palatka, 

Fla.: St. Johns River Water Management District. 

PROJECT (LA-3-301-M): MARSH FLOW-WAY RESTORATION

PROGRAM: Restoration 
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PRIORITY: 1 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments; degradation of downstream lakes; low recreational and aesthetic 

values 

PROJECT OBJECTIVE: To restore muck farm land to wetland in order to filter nutrientrich water from Lake Apopka and re-establish fish and wildlife habitat. Nutrients will 

be removed from Lake Apopka as water is circulated through the marsh, and 

downstream lakes will receive a higher quality discharge. 

SCOPE OF WORK: Demonstration project—Design and construct pump stations, 

spillways, levees, culverts, weir, ponds, and inlet and outlet structures to build a 

demonstration project on 750 ha (1,850 ac) of muck farm land. Restore approximately 

365 ha (900 ac) to wetland, of which 225 ha (550 ac) is the monitored flow-way. Plant 

three 2-ha (5-ac) test plots with diverse native wetland plant species to determine 

success of different species and planting techniques. Flow water from Lake Apopka 

through the project to determine the nutrient removal efficiency of the wetland at 

various water depths and flow rates. Monitor hydrology, hydraulics, soil and water 

chemistry, vegetative development, and wildlife. 

Full Marsh Phase I—Design and construct the full 1,380-ha (3,400-ac) marsh flow-way 

in three phases, based on monitoring information from the demonstration project. 

Develop and test techniques to minimize initial flushing of nutrients from flooded 

muck soils. Plan and implement monitoring programs for hydrology, hydraulics, soil 

and water nutrient chemistry, vegetation, pesticides, and wildlife. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: Completion of the project 

will result in water quality improvements occurring more rapidly in response to the 

nutrient load reduction efforts in the lake, reduced nutrient levels in the lake water, 

improved water quality of downstream discharges, entrapment of flocculent sediments, 

burial and bioattenuation of farmed soils with residual pesticides, and establishment of 

fish and wildlife habitat. 

STATUS: Demonstration project—Design criteria were developed for the demonstration 

phase of the marsh flow-way restoration. The Center for Wetlands at UF and Post 

Buckley Schuh and Jernigan reviewed the design, and the design was further reviewed 

by FWC and FDEP. Negotiations with FDEP regarding a permit for the project started 

in April 1989 and were concluded in November. Two major construction contracts 

included Couch Pumps for repair and modification of existing pumps and for 

installation of pump controls and fuel system, and Phillips & Jordan for construction. 
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Construction started in December 1989 and was substantially completed by December 

1990. 

A “shakedown” period of operation, November 1990 through mid-February 1992, 

involved sheetflow establishment through the southern wetland cell. In mid-February, 

the marsh was drawn down to permit experimental planting of 6 ha (15 ac) with 

wetland vegetation. Experimental planting and final scheduled construction, including 

the automatic pump control system, the fuel system, and walkways and platforms for 

monitoring equipment, were completed by August 1991. Both the southern and 

northern cells were flooded in September 1991. Starting in May 1992, pumps were used 

at the inlet to replace low-gravity flows as necessary. 

Because of different past land uses, the southern and northern wetland cells of the 

demonstration project showed different nutrient retention behaviors. The south cell had 

been farmed less intensively and then had been left fallow several years, resulting in 

appreciable wetland vegetation at the time of flooding. This cell provides our best 

model for the future flow-way system. 

Retention of suspended solids (algae, resuspended sediments) was high (>90%) in the 

south cell. Therefore, the water reaching the north cell was already highly treated, 

leaving little potential for additional improvement in the north cell. Between 30% and 

50% of total nitrogen was removed in the south cell, with little potential for additional 

improvement. Phosphorus leached from soils in the south cell for approximately six 

months after start of operation. After that period, removal efficiency for TP varied 

between 30% and 50%. A similar but longer period of leaching from soils in the north 

cell occurred. The high removal of suspended matter in the demonstration flow-way 

resulted in significantly increased transparency of water discharged downstream. 

In late 1992, hydrologic experimentation on the south cell of the marsh included a 

collector ditch reaching out from the south cell weir basin in an attempt to improve flow 

through the system. Filtration efficiency in the cell declined after that time, which was 

caused by unanticipated hydraulic short circuiting. Nutrient and solids retention in the 

south cell did not return to pre-collector ditch levels, and the ditch was plugged in the 

third quarter of 1993. 

The south cell of the demonstration marsh was drawn down between March and July 

1994 to consolidate sediments that had accumulated since November 1990 and to 

experiment with vegetation management and alteration of flow paths. The 

consolidation was successful; vegetation management was only partially successful. 

However, short-circuiting was not disrupted by the drawdown, which was judged to be 

of too short a duration to allow plant growth sufficient to alter flows. Other hydraulic 
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modifications were made to reduce hydraulic short-circuiting, and by the end of the 

year, the system was again in operation. The system operated at low to moderate flows 

until flow was stopped in 1997 to prepare for construction of the first phase of the fullscale flow-way. 

Nutrient removal performance of the Marsh Flow-Way Demonstration Project was 

analyzed in a series of publications (Coveney 1995; Coveney, Lowe, and Battoe 2001; 

Coveney, Stites et al. 2001). 

The Nutrient Storage and Movement Project, conducted by UF, was designed to 

measure the major nutrient constituents in the marsh soil and vegetation; to determine 

the rate of transformation of nutrients to and from the soil, the water column, and 

vegetation; and to estimate the nutrient retention capacity of the system as affected by 

drawdown, drying, re-flooding, and burning. Drawdown successfully compacted the 

solids that had settled in the marsh, but it also allowed soil oxidation sufficient to 

release significant amounts of soluble phosphorus. 

To address the issue of soluble phosphorus release from soils and to follow up 

laboratory batch incubation experiments, a six-month field plot experiment testing 

several soil amendments’ ability to reduce the phosphorus concentration in the water 

column was completed in December 1996. This research was a cooperative effort 

involving SJRWMD and UF. Results indicated that calcium hydroxide and an alum 

residual (aluminum hydroxide floc: a by-product from the use of alum [Al2(SO4)3 or 

aluminum sulfate] as a clarifying agent for drinking water) were both effective in 

trapping phosphorus soil flux when applied on the soil surface. Two larger field-size 

experiments, one within the marsh flow-way property, were conducted in 1998. Alum 

residual was extremely effective in reducing phosphorus soil flux compared to calcium 

hydroxide and gypsum (calcium sulfate). The application of alum residual will be one 

management tool for the full-scale marsh flow-way. During the summer of 2000, 

approximately 650 ac in Phase I of the flow-way were treated with alum residual 

obtained from the city of Melbourne water treatment plant. 

Contracted field work for vegetation monitoring by UF ended in August 1994. The 

Governing Board accepted the final report in January 1998. Over the course of the 

study, a total of 104 plant species were identified in the naturally re-vegetating portions 

of the flow-way project. In addition, this study monitored vegetation growth in three 

2-ha (5-ac) sites that had been planted with 11 species of wetland plants in 1991. 

Above- and belowground live biomass from the August 1991 samples ranged from 268 

to 928 grams per square meter (dry weight). By March 1994, values ranged form 485 to 

1,414 grams per square meter (dry weight). The study documented the development of 
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extensive floating mats in the south marsh. The percentage of sample plots with floating 

mats went from 0% in 1990 to 41% in 1993. The data on plant biomass and on nutrient 

(P and N) content of plants from this study were used by SJRWMD in analyses of the 

nutrient-removal function of the flow-way project. 

In December 1998, GEONEX completed contractual services to interpret vegetation 

communities in the Demonstration Marsh Flow-Way from aerial photography for the 

years 1990–97. The dominant species for the communities and the acreage changes for 

succeeding years were determined. Between 1990 and 1997, the marsh became 

predominantly mixed herbaceous, dominated by cattail (Typha spp.) and Ludwigia spp. 

Evaluation of the experimental planting sites revealed that spikerush, pickerel weed, 

arrowhead, giant bulrush, and giant flag tended to establish quickly and resist invasion 

by cattail. A mixed-species planting strategy may provide the best opportunity to 

generate a diverse, invasion-resistant plant community. 

The high removal of suspended matter in the demonstration flow-way resulted in 

significantly increased transparency of water discharged downstream. Monitoring data 

on hydrology, hydraulics, soil and water chemistry, vegetative development, wildlife, 

and nutrient uptake at various water depths and flow rates were essential to the design 

process for Phase I of the full-scale project. 

LESSONS LEARNED FROM THE DEMONSTRATION PROJECT

• Hydraulic loading values in the range 35–45 m yr–1 (10–12 cm d-1) gave maximum 

flows through the densely vegetated first cell and avoided excessively high water 

elevations at the inlet end. The resistance to flow observed in the demonstration 

project was one reason that up to 13 cells in parallel will be constructed in the fullscale project rather than a single large treatment wetland. Inlet pumps will be used 

to maintain flows during seasonal periods of low lake stage. 

• The wetland filter was capable of removing suspended solids and TP from Lake 

Apopka water at or above target efficiencies of 85% and 30%, respectively (Coveney, 

Lowe, and Battoe 2001; Coveney, Stites et al. 2001). These results confirmed earlier 

projections of P removal efficiency (Lowe et al. 1989, 1992). Nutrient removal 

occurred at the expense of particulate N and P fractions in most periods; dissolved 

fractions usually were either unaffected or augmented in the wetland. Minimal 

channelization and maximal distribution of residence times were required to meet or 

exceed target removal efficiencies for suspended solids and phosphorus. 
SWIM Plan for Lake Apopka 

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• Cumulative leaching of soluble phosphorus after the initial flooding was about 3 g P 

m-2. Methods proposed to deal with the leaching of soluble phosphorus in the fullscale project include soil amendments to bind P, recycling of floodwaters through 

adjacent cells, and minimizing the frequency and duration of drawdowns. 

• De-watering through drawdown was a necessary and effective technique to 

consolidate new sediment in the wetland. 

Full Marsh Phase I—In 1997, the design for Phase I of the marsh flow-way was 

completed. The construction of Phase I was completed for approximately $4.32 million. 

Funds for the construction of the system were partially provided by the following: 

• SWIM Fund ($1.5 million provided in 1996 legislation) 

• Lake County ($750,000) 

• Lake County Water Authority ($250,000) 

• EPA Clean Water Act Fund ($1 million) 

The pump station will discharge water from the four wetland treatment cells back into 

Lake Apopka and down the Apopka-Beauclair Canal. 

In 2002, consultations were initiated with EPA and USFWS to begin operation of the 

flow-way. A plan of operation (EPA 2002), which includes monitoring and management 

of potential soil pesticide exposure, has been submitted for regulatory consultation. 

Operation will begin after completion of those consultations and after Lake Apopka 

water elevations increase above the record lows of 2001–2002, which have been 

insufficient to allow operation. 

The system will receive a hydraulic loading rate of about 10 cm day-1. At this rate, Phase 

I will remove between 8 and 10 metric tons of phosphorus per year, depending on lake 

water quality and actual flow rates. When all phases are operational, the marsh flowway will treat approximately two lake volumes per year and remove, for long-term 

average water quality conditions, about 30 metric tons of phosphorus annually. 

Furthermore, all water discharged from Lake Apopka downstream to the Harris Chain 

will pass through the marsh flow-way. 

Reports

Ann, Y. 1996. Phosphorus immobilization by chemical amendments in a constructed wetland. 

Ph.D. dissertation, University of Florida, Gainesville. 
Detail of Projects 

St. Johns River Water Management District

139 

Ann, Y., and K.R. Reddy. 1999. Influence of chemical amendments on phosphorus 

immobilization in soils from a constructed wetland. Ecological Engineering 14(1):157–167. 

BEM. 2002. Soil removal reports for Clay Island property and Hooper Farms airstrip, Lake 

County, Florida. Orlando, Fla. 

Best, G.R., and M.T. Brown. 1991. Research program manual for Phase II: The Lake Apopka Marsh 

Flow-Way Demonstration Project. Prepared for St. Johns River Water Management District, 

Palatka, Fla. Center for Wetlands, University of Florida, Gainesville. 

Burns & McDonnell. 1997. Lake Apopka Marsh Flow-Way, Phase I, construction plan and cost 

estimate. St. Johns River Water Management District Contract 97W151. Kansas City, Mo. 

Conrow, R. 1990. Quality assurance project plan: Marsh Flow-Way Restoration Demonstration 

Project. St. Johns River Water Management District, Palatka, Fla. 

Conrow, R., and J. Stenberg. 1994. Survival and competitive abilities of wetland species in the 

Lake Apopka demonstration marsh project. Lake Reserv. Manage. 9(2):65–66. 

Coveney, M.F. 1995. Lake Apopka Marsh Flow-Way Demonstration Project: Interim progress 

report. St. Johns River Water Management District, Palatka, Fla. 

Coveney, M.F., E.F. Lowe, and L.E. Battoe. 2000. Performance of a recirculating wetland filter 

designed to remove particulate phosphorus for restoration of Lake Apopka (Florida, USA). 

Pages 231–237. In Proceedings of the Seventh International Conference On Wetland Systems For 

Water Pollution Control, November 11–16, 2000, Orlando, Fla. 

———. 2001. Performance of a recirculating wetland filter designed to remove particulate 

phosphorus for restoration of Lake Apopka (Florida, USA). Water Sci. and Tech. 44:(11–

12):131–136. 

Coveney, M.F., D.L. Stites, L.E. Battoe, and E.F. Lowe. 1993. Nutrient retention in a restored 

wetland used for lakewater filtration. ASLO and SWS 1993 annual meeting, May 30–June 3, 

1993, Edmonton, Alberta. 

———. 1994. Nutrient removal in the Lake Apopka Marsh Flow-Way Demonstration Project. 

Abstracts of presentations. Lake Reserv. Manage. 9:66. 

Coveney, M.F., D.L. Stites, E.F. Lowe, L.E. Battoe, and R. Conrow. 2001. Nutrient removal from 

eutrophic lake water by wetland filtration. Ecological Engineering (submitted). 

D’Angelo, E.M., and K.R. Reddy. 1994. Diagenesis of organic matter in a wetland receiving 

hypereutrophic lake water: Distribution of dissolved nutrients in the soil and water column. 

J. Environ. Qual. 23:928–936. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

140 

[EPA] U.S. Environmental Protection Agency. 2002. Biological assessment—Plan for initial 

operation and maintenance of the Lake Apopka marsh flow-way, Phase I. Region 4, Atlanta. 

Geonex. 1998. Lake Apopka demonstration marsh vegetation analysis. Submitted to St. Johns 

River Water Management District, Palatka, Fla. 

Lowe, E.F., D.L. Stites, and L.E. Battoe. 1989. Potential role of marsh creation in restoration of 

hypertrophic lakes. In Constructed wetlands for wastewater treatment: municipal, industrial and 

agricultural, D.A. Hammer, ed., 710–717. Proceedings from the First International 

Conference on Constructed Wetlands for Wastewater Treatment. Chelsea, Mich.: Lewis 

Publishers. 

Lowe, E.F., L.E. Battoe, D.L. Stites, and M.F. Coveney. 1992. Particulate phosphorus removal via 

wetland filtration: an examination of potential for hypertrophic lake restoration. Environ. 

Manage. 16(1):67–74. 

Olila, O.G., K.R. Reddy, and D.L. Stites. 1996. Influence of drying on phosphorus forms and 

stability in the Lake Apopka marsh. Final report submitted to St. Johns River Water 

Management District, Palatka, Fla. 

———. 1997. Influence of draining on soil phosphorus forms and distribution in a constructed 

wetland. Ecological Engineering 9:157–169. 

Post Buckley Schuh and Jernigan Inc. 1989. Lake Apopka Marsh Flow-Way Project evaluation 

report. Prepared for St. Johns River Water Management District, Palatka, Fla. Orlando, Fla. 

Reddy, K.R., G. Bao, O.G. Olila, and D.L. Stites. 1998 (draft). Effects of chemical amendments on 

marsh soil chemistry and nutrient flux. Final report submitted to St. Johns River Water 

Management District, Palatka, Fla. 

Reddy, K.R., O.G. Olila, E.M. D’Angelo, D.L. Stites, and M. Coveney. 1996. Nutrient storage and 

movement in the Lake Apopka Marsh, Phase III. Contract 94B271:1996. Final report 

submitted to St. Johns River Water Management District, Palatka, Fla. IFAS, University of 

Florida, Gainesville. 

Schipper, L.A., and K.R. Reddy. 1994. Methane production and emissions from four reclaimed 

and pristine wetlands of southeastern United States. Soil Sci. Soc. Am. J. 584:1270–1275. 

[SJRWMD] St. Johns River Water Management District. 1999. Wetland hydraulic investigation 

project, Lake Apopka test channel status report. Technical memorandum 38. Palatka, Fla. 

———. 2001 (draft). Lake Apopka marsh flow-way plan for initial operation and pesticide 

monitoring and exposure management. Palatka, Fla. 
Detail of Projects 

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Stenberg, J., and M. Clark. 1998. Monitoring of natural and planted vegetation in the Lake Apopka 

Marsh Flow-Way Project, August 1993–March 1995. Special Publication SJ98-SP17. Palatka, 

Fla.: St. Johns River Water Management District. 

Stenberg, J., M. Clark, and R. Conrow. 1998. Development of natural and planted vegetation and 

wildlife use in the Lake Apopka Marsh Flow-Way Demonstration Project: 1990–1994. Special 

Publication SJ98-SP4. Palatka, Fla.: St. Johns River Water Management District. 

Stenberg, J.R., D.L. Day, and G.R. Best. 1991. Development of natural vegetation in the Lake Apopka 

Marsh Flow-Way Demonstration Project: Phase I—Baseline conditions, fall 1990. Special 

Publication SJ91-SP11. Palatka, Fla.: St. Johns River Water Management District. 

Marsh Flow-Way Restoration 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Begin operation of Phase I X 

Inlet pump design and construction X X 

Pesticide evaluation X X X X 

Phase II design X X X X 

Phase II construction X X X X

PROJECT (LA-3-302-M): ROUGH FISH HARVESTING

PROGRAM: Restoration 

PRIORITY: 1 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments 

PROJECT OBJECTIVE: To manipulate the food-web structure and/or export nutrients 

from Lake Apopka by harvesting rough fish (primarily gizzard shad) 

SCOPE OF WORK: Remove rough fish (primarily gizzard shad) in Lake Apopka under 

permit from FWC. Catches will be monitored for tonnage and biological data. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project may provide a 

low-cost or no-cost effective method of nutrient removal from Lake Apopka. Other 

beneficial effects of biomanipulation through rough-fish removal could improve surface 

water quality. 
SWIM Plan for Lake Apopka 

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142 

STATUS: Data from Phase II of the Trophic Structure Manipulation Project indicate 

positive food-web changes and improved water quality resulting from rough-fish 

removal in Lake Denham. Phase III of the Trophic Structure Manipulation Project tested 

various harvesting techniques for rough-fish removal in Lake Apopka and found that 

gill nets could provide an efficient and cost-effective method to accomplish large-scale 

rough-fish removal for nutrient depletion and food-web alterations in the lake. 

From 1993 through 2002, commercial fishermen harvested a total of 3,729,945 kg (8.2 

million pounds) of gizzard shad from Lake Apopka. Harvesting removed and exported 

24.62 metric tons (54,253 pounds) of phosphorus and 73.75 metric tons (162,539 pounds) 

of nitrogen from the lake. Low lake levels prevented large-scale harvest of gizzard shad 

in 2001 and the spring of 2002. To improve lake access for commercial fishing, a new 

dock facility was constructed in 2002 on McDonald Canal on the former A. Duda and 

Sons Jem Farm property. Both the large-scale winter commercial harvest and the smallscale year-round harvest will continue in Lake Apopka. 

Successful management of the fish removal process requires accurate estimates of the 

adult gizzard shad stock for the lake. A stock assessment completed in 1995 indicated 

the most probable population of harvestable gizzard shad prior to the 1995 harvest to be 

3,877,582 fish or about 127 fish/acre. Stock estimates for 1996 ranged from 726,288 to 

2,073,744 fish. The estimated harvest for 1997 was 1,186,364 shad or about 39 fish/acre. 

Even allowing for production and growth of young shad, commercial fishermen had 

apparently harvested a significant portion of the standing stock of adult gizzard shad in 

the lake. Downward shifts in length/frequency and declines in catch-per-unit-of-effort, 

lengths and weights were recorded in 1997 through 1999 (Crumpton 2000). Trends from 

the year 2000 experimental gill net samples indicated that the gizzard shad population 

may be recovering. This recovery may be attributed to reduction in fishing pressure by 

commercial fishermen due to low lake levels. 

FWC (Benton et al. 1995) refined a procedure to assign ages to gizzard shad through the 

use of a bony structure (sagittal otolith). An evaluation of 290 fish collected in the spring 

of 1994 showed that commercial gill nets (>4.0-in. mesh) caught fish of two years of age 

or more. Females grew faster than males and survived longer; few males survived 

beyond two years. Estimates of mortality for ages 0 to 3 from blocknet samples gave a 

range of total annual mortality of 57–85%. 

Reports

Benton, J., K. Taylor, C. Adams, and R. Hudson. 1995. Methodology and analysis of the gizzard 

shad population of Lake Apopka in central Florida using sagittal otoliths. Fisheries Research 
Detail of Projects 

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143 

Laboratory, Florida Game and Fresh Water Fish Commission. St. Johns River Water 

Management District, Palatka, Fla. 

Crumpton, J. 1995. Lake Apopka rough fish removal completion report for 1993 and 1994. 

Florida Game and Fresh Water Fish Commission. 

Crumpton, J.E., and W.F. Godwin. 1997. Rough fish harvesting in Lake Apopka, summary report, 

1993–97. Special Publication SJ97-SP23. Palatka, Fla.: St. Johns River Water Management 

District. 

———. 2000. Experimental gill nets in Lake Apopka. Florida Fish and Wildlife Conservation 

Commission. Contract 99W308. Prepared for St. Johns River Water Management District, 

Palatka, Fla. 

Godwin, W.F., J.E. Crumpton, E.F. Lowe, M.F. Coveney, L.E. Battoe, and D.L. Stites. 1994. Fish 

harvesting for nutrient removal and trophic state effects in Lake Apopka, Florida. Lake 

Reserv. Manage. 9(2):76–77. 

Hackett, W.C., and O.C. Thompson. 1991. Biofermentation pilot study for water hyacinth and gizzard 

shad composting. Special Publication SJ91-SP13. Palatka, Fla.: St. Johns River Water 

Management District. 

Schramm, H.L., Jr., and L.L. Pugh. 1997. Gizzard shad stock estimate for Lake Apopka, Florida, 1995. 

Miss. Coop. Fish and Wildlife Res. Unit. Special Publication SJ97-SP10. Palatka, Fla.: St. 

Johns River Water Management District. 

———. 1997. Gizzard shad stock estimate for Lake Apopka, Florida, 1996. Miss. Coop. Fish and 

Wildlife Res. Unit. Special Publication SJ97-SP11. Palatka, Fla.: St. Johns River Water 

Management District. 

Rough Fish Harvesting 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Rough fish harvest X X X X X X X X X X X X 

Fisheries monitoring X X 

Gizzard shad stock estimate X X 

PROJECT (LA-3-303-M): WETLAND RESTORATION

PROGRAM: Restoration 

PRIORITY: 1 
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144 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments; low recreational and aesthetic values 

PROJECT OBJECTIVE: To restore muck farm land east of the Apopka-Beauclair Canal 

and examine restoration for effects upon water quality, vegetation, and wildlife. 

Various methods for wetland restoration will be examined. As restoration progresses, 

effects upon wildlife will be monitored. 

SCOPE OF WORK: Examine various methods for wetland restoration. Monitor effects 

upon wildlife as restoration progresses. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will result in 

reduced nutrient loading to Lake Apopka and reduced downstream discharges and 

provide additional habitat for fish and wildlife. 

SUMMARY AND STATUS: The 1996 Legislature determined that it was in the public 

interest to pursue a total farm buyout, and the state appropriated $20 million toward 

that goal (Appendix A). SJRWMD signed an agreement with the USDA WRP to receive 

up to $26 million in matching land acquisition funds for the NSRA. In 1997, the Florida 

Legislature appropriated an additional $45 million for purchasing additional 

agricultural lands within the basin. The land acquisition phase of the restoration effort 

has been completed, with the exception of a few non-crop growing properties. A total of 

5,554 ha (13,713 ac) are now under public ownership, and further application of 

pesticides and fertilizers has been halted. 

SJRWMD will develop restoration plans with the concurrence of NRCS, USFWS, and 

FDEP and in coordination with FWC, FOLA, and other interested parties. All of the 

SJRWMD-acquired muck lands on the North Shore will eventually be restored to 

wetlands and other aquatic habitat. 

Restoration work will include treatment of soils with alum residual to bind the initial 

flux of phosphorus from the soils; plugging of abandoned irrigation wells; 

modifications to the extensive network of drainage, pump, and levee systems; planting; 

and monitoring the progress of habitat development. Other capital improvement 

projects include fence construction, bridge replacement and repair, and other access 

improvement projects that will protect SJRWMD property from damage or theft or 

provide safe access for public uses. Partial funding for initial restoration work is being 

provided by NRCS. 
Detail of Projects 

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Initial restoration activities are already in progress on the 3,645 ha (9,000 ac) enrolled in 

the WRP (Duda and ZDWCD Unit 2). The application of a soil amendment on the 

former Duda farm has been completed. This amendment, a by-product of potable water 

treatment containing reacted alum and activated carbon, will absorb much of the excess 

phosphorus left in the soil by the farming activity. Repairs to levees necessary to 

manage water for the initial restoration period are completed. In addition, most of the 

remaining buildings and debris have been cleared from the NSRA. 

An additional methodology implemented to reduce phosphorus loadings to Lake 

Apopka is to treat pumped discharges from ZDWCD Unit I and Unit II. When 

SJRWMD acquired the ZDWCD properties, ZDWCD had already implemented a liquid 

alum treatment system in Unit II, but discharges from Unit I were untreated. In 

September 2001, it became necessary to discharge water from Unit I, so SJRWMD 

implemented a second liquid alum treatment system. To improve water treatment and 

water control efficiency, SJRWMD has contracted with a consultant to redesign both 

alum injection systems. The redesign is expected to be completed and implemented by 

mid-2003. 

As part of the acquisition process, all properties received an ESA in accordance with 

ASTM Standard E1527. An ESA usually consists of four phases. The first phase is an indepth review of the documents available concerning how the land was used, what the 

land was used for, and what potential contamination issues might be present. The 

second phase implements sampling based upon the recommendations made in the first 

phase. The third phase involves the delineation and development of a remediation plan 

for any contamination found. The fourth phase is remediation, additional sampling to 

confirm the adequacy of the remediation, and a final report. At the purchased 

properties, on-site remediation included removal and disposal of over 18,600 tons of 

soil. 

To evaluate the possibility that a significant contamination source might have been 

missed during the ESA process, SJRWMD contracted an independent audit of the ESA 

investigations. The audit found that the ESAs were conducted within the ASTM 

guidelines and that there were no substantial deficiencies. The audit included some 

recommendations for additional work, which have been addressed. 

SJRWMD also contracted for an environmental risk assessment (ATRA 1997) and a 

second followup report (ATRA 1998) to examine the risk to wildlife posed by 

restoration of the former agricultural areas. The results of the environmental risk 

assessment indicated that soil pesticide residues did not present an acute toxicity risk to 

wetland fish and wildlife (ATRA 1997, 1998). However, there was concern for potential 

long-term, sub-lethal effects of DDT residuals on growth or reproduction of top-level, 
SWIM Plan for Lake Apopka 

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146 

predatory birds. The reports recommended, and SJRWMD concurred, that long-term 

monitoring of the site was necessary when the restoration flooding commenced. 

By August 1998, SJRWMD, in partnership with WRP, had purchased most of the farms 

east of the Apopka-Beauclair Canal: Duda Farm, Zellwin Sand Farm, and ZDWCD 

Units 1 and 2. The farmers in Unit 2 were asked to leave their fields shallowly flooded 

following their final crop harvest in the summer of 1998. Shallow flooding for 4–6 

weeks was standard farming practice at the end of each year’s growing season, in order 

to minimize soil subsidence and erosion and to control nematodes. SJRWMD made this 

request in order to minimize discharge of P-rich water to the lake and to inhibit growth 

of terrestrial vegetation. Rainfall during the fall of 1998 caused these fields to remain 

flooded. The fields were to be drained during the winter and treated with a soil 

amendment (alum residual) to prevent P release when restoration flooding commenced. 

Over the past 50 years, migratory birds have used Florida’s flooded farm fields during 

July, August, and September (Stevenson 1972; Sykes and Hunter 1978; Kale et al. 1990). 

The late-summer conditions of 1998 were similar to previous years. However, as water 

levels in the farm fields began to rise with seepage and rainfall, and as more birds and 

more species of birds arrived, the situation became unique and unprecedented. By the 

annual Audubon Christmas Bird Count (CBC), there was a large diversity of waterfowl, 

shorebirds, marsh birds, and thicket species. The total count was 174 species, likely a 

record for inland sites in North America (1998–99 CBC issue of American Birds; also, 

http://birdsource.tc.cornell.edu/cbcdata/). Although small flocks of 20–30 American 

white pelicans were seen on the lake during winter months in previous years, the 1998–

99 CBC recorded 400 American white pelicans. The total Christmas count of American 

white pelicans in Florida that year totaled 6,298, with all inland sites accounting for 

1,173 birds. 

In December 1998, the population of American white pelicans on the NSRA rose to over 

3,500 in one day’s count. Also that month, the first mortalities were recorded (several 

dead pelicans were initially observed in November, but these deaths were not 

recorded). Over the next four months, 441 American white pelicans, 43 wood storks, 34 

great egrets, 58 great blue herons, and smaller numbers of 20 other bird species died onsite. In February 1999, USFWS attributed the deaths to organochlorine pesticide (OCP) 

poisoning. SJRWMD had begun draining the site in November 1998. Pumping was 

accelerated in January 1999. By mid-February 1999, the entire NSRA farm field area had 

been drained. Since then, the fields have been kept dry and have become vegetated with 

prairie and upland shrub communities. 

In March 1999, a team of experts from 13 federal, state, county, and private 

organizations convened as the technical advisory group to the investigation. The team 
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included representatives from SJRWMD, USFWS, NRCS, FDEP, EPA, FDACS, the 

Florida Department of Health, FWC, the Florida Audubon Society, UF, FOLA, Lake 

County, the Lake County Water Authority, Orange County, and ATRA, Inc., a 

toxicological consultant to SJRWMD. 

SJRWMD and NRCS are providing the leadership and the majority of the funding for 

the pesticide study. The other team members are providing staff time and specific 

resources and review of work products. 

A massive $1.5 million investigation was undertaken in an effort to determine the cause 

of the bird mortality and to reassess the potential risks of OCPs to wildlife. During 1999, 

a total of 920 soil samples were taken from 709 locations and analyzed at a laboratory 

chosen for its extensive experience with OCPs, especially toxaphene. In addition to the 

soil samples, 158 tissues from 34 birds and 36 whole fish (six species) were analyzed for 

pesticide levels by the same laboratory. All data on soils, sediments, and tissues (bird 

and fish) were provided to Exponent, a consulting firm based in Bellevue, Washington. 

Their analysis of the data and the draft report on the mortality event were completed 

for review in September 2000. A further draft, which incorporated comments from 

academic and agency reviewers, as well as new data from USFWS, was received in 

April 2003. 

The investigation has shown that soil pesticide levels are not uniform in the various 

units of the NSRA. Because of its lower levels of OCPs, the Duda property, especially 

the eastern portion, presents the lowest risk to wildlife and has been proposed for 

interim flooding. A Biological Assessment and interim restoration plan for a portion of 

the Duda property was submitted by NRCS to USFWS in June 2001 (USDA 2001). A 

Biological Opinion with an incidental take statement was received from USFWS in 

April 2002 (USFWS 2002). The 700-ac site known as Duda sub-east has now been 

reflooded, and the site will be intensively monitored for at least one year. After a year, 

the collected data will be reviewed by SJRWMD, NRCS, and USFWS, and a final level of 

monitoring will be proposed. This information will also assist in the development of 

future management strategies for other portions of the NSRA. 

One of the recommendations of Exponent and the academic and agency reviewers was 

for additional studies to more precisely quantify bioaccumulation of OCPs in wildlife. 

In addition to the proposed interim management plan for the east Duda property, 

SJRWMD has contracted with the USGS Florida Caribbean Science Center and UF for a 

four-part investigation to provide essential insights into the movement of pesticides 

from the soils to biota on the NSRA. Bioaccumulation models can then be more 

accurately calibrated for the development of restoration plans for the various parts of 

the NSRA. The investigation’s components include the following: 
SWIM Plan for Lake Apopka 

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148 

• Experiments to address the potential for pesticides to quickly flush from the highly 

organic NSRA soils when first inundated 

• Experiments in microcosms using a matrix of pesticide and soil carbon levels to 

investigate the bioaccumulation of pesticides into fish and crayfish as a function of 

both soil pesticide and carbon levels 

• Experiments in replicated 0.25-ac fenced and screened ponds built on the NSRA at 

three sites with distinct pesticide concentrations. These ponds will be stocked with a 

variety of typical organisms and the bioaccumulation of pesticides will be evaluated 

under natural conditions 

• The bioaccumulation and distribution of pesticides within caged great egrets fed fish 

grown in fenced and screened ponds on the NSRA. This investigation will track the 

movement of the actual pesticide mixtures on the NSRA from fish into the various 

tissues of a common top-level predator common on the NSRA. 

The study is expected to be complete by the end of 2004. 

Additional sampling of soils in the NSRA has identified at least one area of high OCP 

contamination; this area is adjacent to a former airplane landing strip. By January 2003, 

9,203 tons of contaminated soils from this area had been excavated and removed for 

disposal at an approved landfill. Remediation methods for other potential “hot spot” 

sites, as well as for the overall field sites, are being considered and include the 

following: 

1. Localized contamination: The likely remediation approach will be excavation and 

disposal of waste at an approved landfill. 

2. Widespread contamination from normal farming operations: Remediation may 

include natural attenuation and biological treatment in place. Methods to encourage 

microbial breakdown of pesticide residues and creation of new sediments should 

result in surface sediment contaminant concentrations that decline to safe levels. 

These goals can be attained by 

• Shallow flooding that will shift sediment chemistry to conditions appropriate for 

the chemical breakdown of many pesticide residues 

• The colonization of wetland plants that will rapidly provide material for new 

sediments through decomposition 
Detail of Projects 

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• The accumulation of these new sediments that will dilute and bury the old 

sediments. 

3. Application of innovative treatments for large areas: New treatments may be 

examined but would likely need to be adapted to work in the NSRA. 

A pilot remediation project to evaluate the effectiveness of using lake sediments to cap 

and isolate impacted surface soils on the former farmlands was initiated with Foster 

Wheeler Environmental Corporation. Suitable materials dredged from Lake Apopka 

would be placed over OCP-contaminated areas, thereby eliminating the pathway for 

exposure to human and/or ecological receptors. The efficiency of this potential 

remediation technique will be evaluated as a complete remediation procedure is 

developed. 

After remediation is complete, SJRWMD will, in the short term, flood the NSRA to 

begin shallow-marsh development. The present long-term restoration plan considers 

several potential management areas such as shallow marsh, deep marsh connected to 

the lake, and shorebird management areas. As final restoration activities are developed, 

SJRWMD may consider and implement other appropriate management alternatives as 

well. 

Reports

ABB. 1998. Phases I and II environmental site assessment reports, Clarence Beall Jr. property. 

Lake Apopka Restoration Agricultural Lands Acquisition Program, Orange County, Fla. 

———. 1998. Phases I and II environmental site assessment reports, Stroup Farms. Lake 

Apopka Restoration Agricultural Lands Acquisition Program, Orange County, Fla. 

Ann, Y. 1996. Phosphorus immobilization by chemical amendments in a constructed wetland. 

Ph. D. dissertation, University of Florida, Gainesville. 

ATRA, Inc. 1997. Environmental risk assessment of a Lake Apopka Muck Farm Wetlands 

Restoration. Tallahassee, Fla. Prepared for St. Johns River Water Management District, 

Palatka, Fla. 

———. 1998. Comparison of muck farm restoration levels to concentrations in Lake Apopka 

North Shore Wetland Restoration Area. Occupational and Environmental Services. 

Tallahassee, Fla. Prepared for St. Johns River Water Management District, Palatka, Fla. 

Beasley, L.E. 1998. Phase II remediation plan and Phase IV remedial action report for Stroup 

Farms. Reports certified by HSW Engineering, Inc. Orlando, Fla. 
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150 

———. 1998. Phase I final environmental site assessment remediation plan and Phase III 

remediation plan and remedial action report for Grower’s Precooler. Reports certified by 

HSW Engineering, Inc. Orlando, Fla. 

———. 1998. Phase III remediation plan and Phase IV remedial action report for Long Farms. 

Reports certified by HSW Engineering, Inc. Orlando, Fla. 

———. 1999. Remedial action report for Grinnell Farms. Certified by Streamline Environmental. 

Tampa, Fla. 

———. 1999. Phase III environmental site assessment for Hensel and Rodgers property. 

Certified by Streamline Environmental. Tampa, Fla. 

———. 1999. Phase III remediation plan for Potter and Sons, Inc. Certified by Streamline 

Environmental. Tampa, Fla. 

———. 1999. Phase III remediation plan and report for Hickerson property. Both reports 

certified by Streamline Environmental. Tampa, Fla. 

———. 2000. Phase III remediation report and Phase IV remedial action report for World 

Foliage Resources. Reports certified by Streamline Environmental. Tampa, Fla. 

BEM. 1997. Phase I environmental site assessments for Lust Farms and Lust/Long Precooler. 

Orlando, Fla. 

———. 1998. Phase II environmental site assessments for Lust Farms and Lust/Long Precooler. 

Orlando, Fla. 

———. 1998. Final Phase II environmental site assessment, Grower’s Precooler. Orlando, Fla. 

———. 1998. Phase II environmental site assessment, Zellwood Drainage and Water Control 

District. Orlando, Fla. 

———. 1999. Phase I environmental site assessment and Phase II final environmental 

assessment for Grinnell Farms. Orlando, Fla. 

———. 1999. Phase I environmental site assessment, Wallace Carrots. Orlando, Fla. 

———. 1999. Phase I environmental site assessment, Marsell property. Orlando, Fla. 

———. 1999. Final Phase I, Final Phase II, and Final Phase III environmental site assessments 

and tank closure assessment report for Potter and Sons. Orlando, Fla. 
Detail of Projects 

St. Johns River Water Management District

151 

———. 2000. Phase I environmental site assessment, Davison properties. Orlando, Fla. 

———. 2000. Lake Apopka airstrip investigation report, Lake and Orange counties. Orlando, 

Fla. 

———. 2000. Parcel F waste removal report. Orlando, Fla. 

———. 2000. Phase II environmental site assessment, Marsell property. Orlando, Fla. 

———. 2000. Tank closure assessment report, Zellwin Farms. Orlando, Fla. 

———. 2000. Tank closure assessment report, Duda and Sons, Inc. Orlando, Fla. 

———. 2000. Tank closure assessment report, Lake Apopka lock and dam, Mt. Dora, Fla. 

Orlando, Fla. 

———. 2000. Final phase III environmental site assessment, parcel B pumphouse. Orlando, Fla. 

———. 2001. Lake Apopka airstrip investigation report, Lake and Orange counties. Followup 

report. Orlando, Fla. 

———. 2001. Final phase III environmental site assessment and tank closure assessment reports 

for parcel E pump station 2. Orlando, Fla. 

———. 2001. Phase I environmental site assessment update, A. Duda and Sons property, Lake 

Jem, Florida. Orlando, Fla. 

———. 2002. Phase I environmental site assessment, World Foliage Resources, Inc. Orlando, 

Fla. 

Bowen, P.J. 2001. Lake Apopka North Shore Restoration Area map book. St. Johns River Water 

Management District, Palatka, Fla. 

Conrow, R., E. Marzolf, M.F. Coveney, and E. Lowe. 2001. Proposal for interim management of 

the Lake Apopka North Shore Restoration Area. St. Johns River Water Management District, 

Palatka, Fla. 

Earth Systems Engineers, Inc. 1997. Phase I environmental site assessment, Phase II assessment, 

and Phase III assessment, Lake Jem Farm, northern shore of Lake Apopka, Lake Jem, 

Florida. 

Exponent, Inc. 2003 (draft final report). Analysis of avian mortality at the North Shore 

Restoration Area of Lake Apopka in 1998–1999. Prepared for St. Johns River Water 

Management District, Palatka, Fla. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

152 

Foster Wheeler Environmental Corporation. 2001. Reports for demonstration capping project, 

Lake Apopka, Florida: Sampling and analysis plan; Contaminant mobility study; Draft 

preliminary project design report, Phase I; Project description; Contaminant mobility 

evaluation within a cap. All prepared for St. Johns River Water Management District, 

Palatka, Fla. 

Golder Associates, Inc. 1997. Phase I, Phase I—federal easement, and Phase II (2 vols.) 

environmental site assessments for Zellwin Farms parcel, Orange County, Florida. 

Jacksonville, Fla. 

———. 1997. Report of facility report for lead-based paint and Survey report of asbestoscontaining building materials. Jacksonville, Fla. 

Gross, T.S., M. Sepulveda, S.D. Ruessler, J.N. Wiebe, and C.M. Wieser. 2002. Microcosm and 

mesocosms evaluation of the bioaccumulation of chlorinated pesticides in the North Shore 

Restoration Area. SIS4944. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_Projects]. 

Florida Caribbean Science Center, Gainesville. 

Harding Lawson Associates. 1998. Phases I and II environmental site assessments, Zellwood 

Drainage and Water Control District. Orlando, Fla. 

———. 2000. Limited site assessment and soil remediation, Duda Farms property. Orlando, Fla. 

———. 2001. Limited soil sampling and analysis, North Shore Restoration Area, Lake Apopka, 

Florida. Orlando, Fla. 

Hoge, V.R. 2001 (draft). Alum residual as a soil additive: A literature review. White paper. St. 

Johns River Water Management District, Palatka, Fla. 

HSW Engineering, Inc. 1998. Remediation plan, Stage I; Report of remediation activities, Stage 

II; and Phase IV report of remedial activities, Stage II, for Lust Farms. Phase III remediation 

plan, Stage I, for Lust/Long Precooler. Orlando, Fla. 

JEA. 1993. Site audit and environmental assessment of George Keen Ranch. Gainesville, Fla. 

Marburger, J.E., W.E. Johnson, D.R. Douglas, and T.S. Gross. 1999. Pesticide contamination of 

fish and sediments in the Emeralda Marsh Conservation Area: Relevance to fisheries 

establishment in flooded muck farms. Technical memorandum 31. St. Johns River Water 

Management District, Palatka, Fla. 

Orange County Environmental Protection Department. 1999. Lake Apopka investigation. 

Orlando, Fla. 
Detail of Projects 

St. Johns River Water Management District

153 

Parsons Engineering Science, Inc., and GeoSyntec, Inc. 2000. Review of documentation for the 

location and remediation of possible pesticide/chemical sites at the North Shore Restoration 

Area, Lake Apopka, Florida. Prepared for the St. Johns River Water Management District, 

Palatka, Fla. 

Professional Service Industries, Inc. 1996. Remedial plan/supplemental contamination 

assessment report for Zellwin Farms. Winter Park, Fla. 

———. 1997. Remedial plan for Lake Jem Farm. Winter Park, Fla. 

———. 1997. Contamination assessment report for Zellwin Farms and Remedial 

plan/supplemental contamination assessment report for Zellwin Farms, addendum II. 

Winter Park, Fla. 

Robinson, H. 1999. Bird report, Zellwood Drainage and Water Control District Unit 1, Unit 2, 

and the Zellwin Sand Farm property at Zellwood, Florida. August 15, 1998–August 14, 1999. 

Prepared for St. Johns River Water Management District, Palatka, Fla. 

———. 2002. Bird usage of Lake Apopka’s North Shore Restoration Area. Zellwood Drainage 

and Water Control District Unit 1, Unit 2, and the Zellwin Sand Farm property at Zellwood, 

Florida. August 15, 1999–August 14, 2000. Prepared for St. Johns River Water Management 

District, Palatka, Fla. 

Rouhani, S., and M.R. Wild. 2000. Statistical and geostatistical analysis of NSRA soil/sediment data. 

Final Report prepared by NewFields, Inc. for St. Johns River Water Management District, 

Palatka, Fla., Contract SD148AA. Atlanta. 

[SJRWMD] St. Johns River Water Management District. 1999. Lake Apopka Restoration Project: 

Wildlife impacts and progress toward remediation. A report to the Honorable Governor Jeb 

Bush and the Legislature of the state of Florida. Palatka, Fla. 

———. 2001. Landfill closure assessment report for Duda Farms. Palatka, Fla. 

Speer, S.W., and C.H. Cunningham. 2000. Subsurface soil exploration, Lake Apopka restoration, 

pilot dredging program, Orange County, Florida. Ardamann & Associates, Inc., Orlando, 

Fla. 

Stout, I.J., and R. Clerico. 2000. Rodent population study in the North Shore Restoration Area, part 1 

(survey of rodents near Lake Apopka). Special Publication SJ2000-SP2. Palatka, Fla.: St. Johns 

River Water Management District. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

154 

Stout, I.J., R. Clerico, and K.B. Clanten. 2001. Rodent population study in the North Shore Restoration 

Area, part 2 (survey of rodents near Lake Apopka). Technical Publication SJ2001-1. Palatka, Fla.: 

St. Johns River Water Management District. 

TASK Environmental. 1997. Phase III remedial plan for Zellwin Farms, Lake Apopka, Florida. 

Tampa, Fla. 

———. 1997. Phase IV remedial action report for Duda Farms, Vol. 1, Lake Apopka, Florida. 

Tampa, Fla. 

———. 1998. Phase IV remedial action report and Interim soil and groundwater assessment 

report, with addendum, for Zellwin Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1998. Phase IV final remedial action report for Duda Farms, Lake Apopka, Florida. 

Tampa, Fla. 

———. 1998. Phase I environmental site assessment of Long Farms, Lake Apopka, Florida. 

Tampa, Fla. 

———. 1998. Phase I environmental site assessment of Clonts Farms, Inc., Lake Apopka, 

Florida. Tampa, Fla. 

———. 1998. Phase I environmental site assessment of Crakes & Sons, Inc., Lake Apopka, 

Florida. Tampa, Fla. 

———. 1999. Phase IV update letters for Duda Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Hensel and Rodgers property, 

Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Hickerson property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments; Phase III remediation plan; and

Remedial action report, for Progressive Growers, Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phase I environmental site assessment of Freeman, Baumgardt, and Bledsole 

property, Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Teddy Smith property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 1999. Phase I environmental site assessment of World Foliage Resources, Inc. Lake 

Apopka, Florida. Tampa, Fla. 
Detail of Projects 

St. Johns River Water Management District

155 

———. 2000. Phase II environmental site assessment of World Foliage Resources, Inc. Lake 

Apopka, Florida. Tampa, Fla. 

———. 2000. Limited contamination assessment report (LCAR) for Zellwood Drainage and 

Water Control District. Tampa, Fla. 

———. 2000. Phases I and II environmental site assessment of NAPA property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2000. Phases I and II environmental site assessment of the Strickland property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 2000. Phases I and II environmental site assessments of the Bates property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 2000. Soil removal activities at areas D & E, Lake Apopka, Florida. Tampa, Fla. 

———. 2001. Phase I environmental site assessment update of the Strickland property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 2001. Phase I environmental site assessment of the Holt property, Lake Apopka, Florida. 

Tampa, Fla. 

———. 2001. Phase I environmental site assessment of the Shaffer property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2001. Phase I environmental site assessment of the Shortz property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2001. Phase IV remediation action report for Progressive Growers, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2001. Tank closure assessment report for pump house 3 and pump house 4, Lake Level 

Canal, Lake Apopka, Florida. Tampa, Fla. 

[USDA] U.S. Department of Agriculture. 2001. Lake Apopka North Shore Restoration Area 

biological assessment and interim restoration plan for Duda property. Natural Resources 

Conservation Service. Gainesville, Fla. 

[USFWS] U.S. Fish and Wildlife Service. 2002. Biological opinion for the interim restoration plan 

for the Duda sub-east property located at the North Shore Restoration Area of Lake Apopka, 

Orange County, Florida. Jacksonville, Fla. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

156 

Wetland Restoration 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Complete restoration plan X X X X X X X X 

Build infrastructure X X X X X X X X X X 

Soil amendment application X X X X X X X

Design, establish, and implement 

monitoring program X X X X X X X X X X X X X X X X

Restoration flooding 

Duda sub-east flooding X X 

Rest of Duda flooding X X X X 

ZDWCD flooding X X X X 

Pesticide study 

Bioaccumulation study 

Field-scale mesocosms X XX X X X X X 

Bird feeding studies X X X X X 

Remediation 

Airstrip cleanup X X X X 

Treatment methodology X X X X 

Implementation X X 

Vegetation assessment 

Aerial photography X X X X 

GIS interpretation and change 

analysis X X X X X X 

PROJECT (LA-2-304-M): LITTORAL ZONE RESTORATION

PROGRAM: Restoration 

PRIORITY: 1 

ISSUE CATEGORIES: Lack of fish and wildlife habitat; poor water quality and 

flocculent sediments; low recreational and aesthetic values 

PROJECT OBJECTIVE: Phase I—To conduct a study of the feasibility of restoring 

littoral zone vegetation behind earthen dikes and to assess the effects of the restored 

littoral zone on gamefish populations. Phase II—To test the feasibility of re-establishing 

native aquatic plant communities in the littoral zone of the lake using man-made and 

natural vegetation barriers for protection of plantings. To examine the potential 
Detail of Projects 

St. Johns River Water Management District

157 

macrophyte seed source from sediments of the various water depth contours of the 

lake. Phase III—To establish test plots of planted wetland species in the lake to 

determine viability under ambient lake conditions and to maintain an ongoing planting 

and monitoring effort 

SCOPE OF WORK: Phase I—Develop a demonstration project to evaluate the feasibility 

of littoral zone restoration by the creation and management of permanent subbasins 

within Lake Apopka. Identify a suitable site for the study in Lake Apopka and conduct 

an economic analysis of the costs of land acquisition, design, construction, drawdown, 

re-vegetation, and management. 

Phase II—Deploy protective barriers along the littoral zone of the lake to protect natural 

and planted aquatic vegetation. Determine the feasibility of sculpturing existing stands 

of cattails to provide protection for more desirable planted aquatic vegetation. Monitor 

effects of barriers on plant growth and water quality. Interpret existing aerial 

photography for wetland vegetation and map. Take sediment cores from transects 

perpendicular to the shoreline and incubate under greenhouse conditions to determine 

the natural seed bank. 

Phase III—Plant and monitor littoral zone sites. Map vegetation in the existing littoral 

zone area around the lake perimeter using a global positioning system (GPS). Compare 

these results with the geographic information system (GIS) maps from earlier aerial 

photography. 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: This project evaluates 

the feasibility of littoral zone restoration by the creation and management of permanent 

subbasins within Lake Apopka or by re-establishing a diverse native aquatic plant 

community behind protective barriers in the littoral zone of the lake. The sediment seed 

bank study will provide data on the macrophyte seed base and possible germination in 

potential expanded littoral zone areas of the lake. The re-establishment of a diverse 

vegetated littoral zone for the lake will result in the partial restoration of habitat once 

present in Lake Apopka. The growth and expansion of submerged aquatic vegetation 

within the lake is a key goal of the restoration plan. Submerged aquatic vegetation 

provides critical and currently missing habitat and will reduce internal nutrient loading 

by reducing the ability of wind-driven currents to resuspend sediments. 

STATUS: The Phase I study was completed and indicated that littoral zone restoration 

by construction of permanent subbasins was not economically feasible. 

Phase II—Field surveys were conducted to determine potential littoral zone sites for 

vegetation restoration efforts. A considerable portion of the shallow shelf zone of Lake 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

158 

Apopka is suitable for some form of aquatic vegetation restoration. Construction and 

testing of light-weight portable floating barriers has been completed. About 5,000 linear 

feet of barrier has been deployed at designated aquatic vegetation planting sites and 

around some stands of existing vegetation. A contract effort to transplant six native 

aquatic plant species behind protective barriers and at unprotected control sites began 

in July 1992 and was completed in December 1993. The six species planted were giant 

bulrush (Scirpus californicus), knot grass (Paspalidium geminatum), spatterdock (Nuphar 

luteum), eelgrass (Vallisneria americana), Illinois pondweed (Potamogeton illinoensis), and 

southern naiad (Najas guadalupensis).

Phase III—Additional aquatic vegetation planting was begun by SJRWMD staff, 

primarily near the northern shore of the lake, in June 1992. By 2001, 40 sites had been 

planted around the 40-mile perimeter of the lake. Planting “events” have been sponsored 

by SJRWMD with county and local governments and FOLA, a citizen advocacy group, 

to restore littoral zone areas fronting public parks along the lake. Both wild and 

purchased native plants are used. As the plants become established, the artificial 

barriers are moved to new sites. One problem that has been noted is the grazing of the 

plants by fish and/or turtles. This has slowed the expansion of the planting zones in 

several cases. 

GPS mapping of vegetation in the littoral zone has been completed and will serve as a 

baseline for future analysis (Conrow and Peterson 2000). Since 1995, Vallisneria

americana (eelgrass) has increased markedly in the lake. In June 1997, 63 patches of 

eelgrass totaling about 1.16 ha (2.87 ac) had been discovered around the lake, and other 

small areas of musk-grass and southern naiad were found and are being monitored for 

expansion. In January 2001, more than 83 patches with a combined area over 2.6 ha 

(6.5 ac) were documented. This spontaneous return of submersed macrophytes may be 

a response to improved underwater light conditions. In addition to providing valuable 

habitat, submersed macrophytes will hasten the recovery of the lake through several 

positive feedback mechanisms. 

Report

Conrow, R., and J. Peterson. 2000. A panel atlas of the major aquatic plants of Lake Apopka, 

Florida, using global positioning and geographic information systems. St. Johns River Water 

Management District, Palatka, Fla. 
Detail of Projects 

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159 

Littoral Zone Restoration 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Vegetation planting X X X X X X X X X X X X X X X X

Vegetation monitoring (planted sites) X X X X X X X X

Aerial photography X X X X 

GPS mapping and analysis 

(lakewide) X X X X X X X X X X X X

PROJECT (LA-3-402-M): NONPOINT SOURCE POLLUTION CONTROL

PROGRAM: Regulatory 

PRIORITY: 2 

ISSUE CATEGORY: Nonpoint pollution sources 

PROJECT OBJECTIVE: To identify and control nonpoint sources of pollution affecting 

Lake Apopka 

SCOPE OF WORK: Support master stormwater planning efforts. Identify stormwater 

conveyance systems and determine potential impact to the lake. Map stormwater 

conveyance systems and compile compliance history. Determine the extent of 

inadequate septic systems around the lake. Assist in the development and 

implementation of stronger local ordinances. Continue SJRWMD compliance and 

enforcement efforts. Assess potential for future enforcement contracts with Lake and 

Orange counties to provide the needed enforcement personnel. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: Improved regulation of 

nonpoint source pollution into Lake Apopka will become important as agricultural and 

point source pollution problems are resolved. This project will address the nonpoint 

source issue. 

STATUS: Using a grant from Orange County, FOLA hired professional planners to 

develop the Lake Apopka Development Design Guidelines. Each of the eight local 

jurisdictions will be asked by FOLA to adopt and apply the shoreline protective 

measures as they approve future developments. Lake County has written a new 

ordinance based on the guidelines, and several new proposed developments have 

incorporated the guidelines. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

160 

The Jones Avenue Regional Stormwater Management Project will provide a regional 

wet detention pond system to improve the water quality in the northern portion of the 

basin. The 16.2-ha (40-ac) project will be located on SJRWMD property within the NSRA 

and will be funded by a cost-share agreement between SJRWMD and Orange County. 

Nonpoint Source Pollution Control 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Review local ordinances X X X X X X X X X X X X X X X X

Design, permitting, and 

construction of Jones Avenue 

Stormwater Park 

X X X X X X X 

PROJECT (LA-3-403-M): NUTRIENT LOADING LIMITS ADOPTION

PROGRAM: Regulatory 

PRIORITY: Completed 

ISSUE CATEGORIES: Agricultural discharges; lack of fish and wildlife habitat; poor 

water quality and flocculent sediments; degradation of downstream lakes; nonpoint 

pollution sources; future basin development 

PROJECT OBJECTIVE: To develop and adopt a phosphorus loading limit rule and 

more-stringent permitting criteria, if necessary, to protect water resources in the Lake 

Apopka Basin 

SCOPE OF WORK: Incorporate information from other projects, including external and 

internal nutrient budgets, phytoplankton-nutrient interactions, and mathematical 

modeling to recommend final PLRGs and performance criteria for Lake Apopka. Draft 

special basin criteria for Lake Apopka for incorporation under appropriate SJRWMD 

rules. These special basin criteria will comply with mandates of 62-40.420, F.A.C. 

Evaluate a number of more-stringent review criteria, such as smaller size threshold for 

projects requiring permits, treatment of larger volumes of stormwater to protect 

receiving water quality, identification and protection of natural habitats, and 

establishment of a buffer for the lake from future development pressures. Hold rule 

workshops to promote public input before final rule adoption by the Governing Board. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will result in 

decreased nutrient loading to the Lake Apopka Basin. 
Detail of Projects 

St. Johns River Water Management District

161 

STATUS: Regulatory and land acquisition actions that will decrease phosphorus 

loading to the basin have already been initiated. A proposed Works of the District Rule 

to regulate phosphorus loading to Lake Apopka was approved by the Governing Board 

in October 1994 and published in November 1994. Challenges to the rule were filed in 

December, and an administrative hearing on the challenges was held in late January 

1995. The hearing officer found in favor of the petitioner, ruling that SJRWMD did not 

have authority to promulgate the rule. In addition, he found against SJRWMD on some 

points of fact concerning the sediment accumulation rate. Subsequent contracted 

research with UF provided additional data that SJRWMD used to verify the original 

measurements. 

SJRWMD and FDEP staff cooperated with the legislative delegation and FOLA for 

passage of 1996 legislation, which included authority for SJRWMD to develop a 

nutrient limitation rule for the lake and to set a phosphorus criterion for Lake Apopka 

of 55 ppb if SJRWMD chose not to act. 

The phosphorus criterion is a numeric interpretation for phosphorus of the Class III 

narrative nutrient criterion. SJRWMD responded with revisions to Chapter 40C-4, 

F.A.C., and Applicant’s Handbook: Management and Storage of Surface Waters (Appendix I), 

effective August 1996. This rule established a phosphorus criterion of 55 ppb for Lake 

Apopka pursuant to the mandate of the Lake Apopka Restoration Act. It has been used 

to establish discharge limitations for all regulated activities within the Lake Apopka 

drainage basin that are permitted to discharge, directly or indirectly, into Lake Apopka, 

the Lake Level Canal, or the McDonald Canal. 

A revised draft technical memorandum that derived a PLRG for phosphorus in Lake 

Apopka was completed in 2000. The recommended allowable phosphorus loading to 

Lake Apopka from all sources is 15.9 metric tons per year. This loading is compatible 

with restoration goals. 

SJRWMD staff worked to further improve the technical basis of the nutrient limitation 

rule and began the rule promulgation process again in 1999. A Notice of Proposed Rule 

Development was published in the Florida Administrative Weekly on December 29, 2000 

(Appendix A). On January 31, 2001, a public workshop was held in Orlando to discuss 

the proposed rule amendments. Environmental Research and Design (ERD) was 

contracted to review SJRWMD’s existing stormwater treatment criteria to determine if 

they were adequate to limit postdevelopment phosphorous loading. ERD submitted a 

draft report to SJRWMD in July 2001. Based on the consultant’s report and further 

discussions, SJRWMD staff incorporated several revisions to the proposed rule. The 

proposed rule was approved by the Governing Board in April 2002 and was published 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

162 

in the Florida Administrative Weekly on April 19, 2002. Following concern by the public 

over the implementation cost of the rule, SJRWMD considered less costly alternatives 

that would still meet the statutory objectives of the proposed rule. The final rule 

adoption hearing was held in December 2002. The rule became effective in March 2003. 

Reports

Coveney, M.F. 2000 (draft). Sedimentary phosphorus stores, accumulation rates, and 

sedimentation coefficients in Lake Apopka. Prediction of the allowable phosphorus loading 

rate. Technical memorandum. St. Johns River Water Management District, Palatka, Fla. 

Environmental Research and Design, Inc. 2001 (draft). Evaluation of water quality stormwater 

regulations for the Lake Apopka Basin. Final report submitted to St. Johns River Water 

Management District, Palatka, Fla. 

[SJRWMD] St. Johns River Water Management District. 1994. Public hearing, Chapters 40C-1 

and 40C-61, F.A.C. Pollutant load reduction goals for Lake Apopka. F.O.R. 94-1496. Palatka, 

Fla. 

———. 1994. Economic impact statement for the proposed amendments to Chapter 40C-61, 

F.A.C. Works of the District Basins. (Lake Apopka Works of the District). SJEIS 94-02. 

Palatka, Fla. 

PROJECT (LA-6-501-M): DISTRICT WATER MANAGEMENT PLAN

PROGRAM: Planning 

PRIORITY: 1 

ISSUE CATEGORY: Future basin development 

PROJECT OBJECTIVE: To regularly evaluate progress being made in implementing the 

DWMP and to update the DWMP every five years 

SCOPE OF WORK: Prepare annual progress reports on the DWMP. For each DWMP 

update, identify the state of water resources in SJRWMD and water resource issues by 

water management district area of responsibility and major watershed, using resource 

assessments and other tools; develop strategies to address identified issues with a focus 

on what can be accomplished within the next five-year period; modify goals, objectives, 

policies and performance measures for SJRWMD or SJRWMD programs, as needed. 
Detail of Projects 

St. Johns River Water Management District

163 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: During the DWMP 

update process, SJRWMD works closely with state agencies, local governments, and 

others to identify water resource issues and develop strategies to address them. The 

DWMP includes a chapter on watersheds that identifies and addresses issues specific to 

the Lake Apopka Basin. 

STATUS: The original DWMP was completed in spring 1995, and the first update of the 

DWMP was completed in spring 2000. The second update will be due to FDEP for 

review in November 2004. Lake Apopka SWIM program staff provide input concerning 

Lake Apopka for annual progress reports and participate in other reporting efforts as 

requested. They also are involved in the development of SJRWMD’s Annual Work Plan 

and Budget, for which the DWMP sets direction. In addition, given the role the DWMP 

plays as SJRWMD’s primary long-term planning tool, they assist in the preparation of 

periodic updates of the DWMP. 

The original DWMP included a chapter organized by county to assist regional planning 

councils and local governments in addressing water resource issues. The Local 

Government Partnership Project followed and resulted in SJRWMD’s publication of 

county water resource atlases in 1996 that contain strategies developed jointly by 

SJRWMD and local governments in each county, along with lists of critical water 

resource issues, current initiatives and maps created for the DWMP and other efforts. 

These atlases have served as a useful tool for linking land and water planning efforts. A 

watersheds chapter replaced the county chapter in the May 2000 DWMP. New county 

water resource atlases that will provide county- and watershed-oriented water resource 

information from the DWMP and other sources was published in 2002. The atlas will be 

updated every five years in order to assure that the best available information is in the 

hands of local government decision makers. 

Reports

[SJRWMD] St. Johns River Water Management District. 2000. District water management plan 

(DWMP) and DWMP executive summary. Palatka, Fla. 

———. 2003. Water resource atlas. St. Johns River Water Management District, Palatka, Fla. 

District Water Management Plan 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Publish annual progress report X X X X X X X

Update DWMP (including 

resource assessments) X X X X X X X X 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

164 

PROJECT (LA-6-502-S): LOCAL GOVERNMENT COMPREHENSIVE PLAN 

REVIEW

PROGRAM: Planning 

PRIORITY: 1 

ISSUE CATEGORIES: Low recreational and aesthetic values; poor water quality and 

flocculent sediments; lack of fish and wildlife habitat; nonpoint pollution sources; 

future basin development 

PROJECT OBJECTIVE: To review and comment on local government comprehensive 

plan amendments, plan updates, and evaluation and appraisal reports (EARs) 

SCOPE OF WORK: Furnish local governments with data and policy-related information 

for their planning process. Review comprehensive plans and plan amendments in 

relation to statutory water management district responsibilities and Chapter 163, FS, 

and its implementing regulations (Rule Chapter 9J-5, F.A.C.). Provide assistance to local 

governments in the preparation of EARs on their comprehensive plans and review 

EARs as requested and as staff time permits. 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: This project will 

provide a vehicle for improved coordination between the Lake Apopka restoration 

effort and local government planning. Inclusion of priority issues associated with 

restoration into the local planning process is necessary to address and prevent future 

problems in the basin. 

STATUS: Adopted EARs for Lake County and its largest cities were due on May 1, 1998. 

They were due for Orange County and its largest cities, including Apopka, Ocoee, and 

Winter Garden, on July 1, 1998. The next step in the process, following or during an 

EAR sufficiency review process conducted by FDCA, is the submission of EAR-based 

comprehensive plan amendments which are reviewed by SJRWMD. The schedule for 

submittal of adopted EAR reports for the years 2002 through 2010 pursuant to Section 

163.3191(9), FS, is listed in Table 6. 

SJRWMD also continues to review regular (not EAR-based) comprehensive plan 

amendments as submitted. 
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Table 6. Evaluation and appraisal report schedule, 2002-2010 

County/Municipality Due Date County/Municipality Due Date 

Lake August 2007 Orange July 2005 

Montverde June 2009 Apopka August 2006 

 Oakland August 2007 

Winter Garden November 2007 

(DCA 2001a) 

Local Government Comprehensive Plan Review 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Review regular comprehensive 

plan amendments X X X X X X X X X X X X X X X X

Review EAR-based amendments X

PROJECT (LA-6-503-M): LAND MANAGEMENT PLAN FOR THE LAKE APOPKA 

RESTORATION AREA

PROGRAM: Planning 

PRIORITY: 1 

ISSUE CATEGORIES: Agricultural discharges; lack of fish and wildlife habitat; low 

recreational and aesthetic values 

PROJECT OBJECTIVE: To develop and implement a land management plan for the 

Lake Apopka Restoration Area, which includes the marsh flow-way and the NSRA 

SCOPE OF WORK: Develop and revise the land management plan for the restoration 

area to include newly acquired properties, and define restoration activities. Update the 

land management plan every five years. Initiate implementation of the plan in 

cooperation with other agencies and the public. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: The Lake Apopka 

management unit is designated as a restoration area. Thus, primary management 

emphasis will reflect the goals and objectives of the SWIM program (lake restoration), 
SWIM Plan for Lake Apopka 

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166 

with secondary emphasis on maintaining or restoring the uplands in good ecological 

health and providing compatible public use. 

STATUS: Legislative directives (Chapters 373 and 375, FS) guide the land management 

process from acquisition evaluations to the development of land management plans. 

These plans identify resource needs and compatible uses. The process provides both the 

mechanism and the opportunity for SJRWMD staff, other agencies, and the public to 

participate in the process. 

The Ocklawaha River Basin Conceptual Management Plan, which contains the Lake 

Apopka Restoration Area, was completed in January 1992 and adopted by the SJRWMD 

Governing Board in March 1992. Development of a land management plan for acquired 

properties is required within one year of purchase, and the plans are revised about 

every five years. 

Land maintenance activities at the Lake Apopka Restoration Area consist largely of 

maintaining the roads, canals, and levees, as well as various mowing efforts. Exotic 

weed control and prescribed burning activities are conducted as needed. Additional 

land maintenance includes maintenance of various facilities, solid waste removal, and 

replacement of bridges, including the bridge over the Apopka-Beauclair Canal. 

Many of the land management activities planned for the Lake Apopka Restoration Area 

have been delayed pending the resolution of restoration plans for the area. It is 

anticipated, however, that once the remediation has taken place and the restoration 

efforts are resumed, various land management activities will resume. 

SJRWMD land management staff have been cooperating with local residents on a 

regional planning effort for the Lake Apopka Basin. FOLA has led the effort—working 

with the region’s local governments, non-profit groups and residents—to develop a 

Lake Apopka Basin Master Plan. This plan encompasses long-term goals for greenways, 

trails, recreation, and ecotourism within the basin. Despite the uncertainty surrounding 

the restoration plans, SJRWMD has been cooperating with the regional planning effort 

to explore the possibility of trail connections and other recreational opportunities on the 

SJRWMD-owned property. Possible public use and recreational activities planned for 

the property include construction of observation towers, establishment of parking areas, 

and installation of entrance signs and interpretive kiosks. 

Reports

Donelin, L.N., and R.E. Turnbull. 1992. Draft conceptual management plans for District-owned 

lands: Ocklawaha River Basin. St. Johns River Water Management District, Palatka, Fla. 
Detail of Projects 

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[SJRWMD] St. Johns River Water Management District. 2000. Land acquisition and 

management: 2000 five-year plan. Palatka, Fla. 

———. 2001. Recreation guide to District lands. Palatka, Fla. 

Land Management Plan for the Lake Apopka Restoration Area 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Revise land management plan to 

include acquired properties X X X X X 

Road, levee, and canal maintenance X X X X X X X X X X X X X X X X

Vegetation maintenance X X X X X X X X X X X X X X X X

Prescribed burning X X X X X X X X 

Exotic plant control X X X X X X X X X X X X X X X X

Structure maintenance and repair X X X X X X X X X X X X X X X X

New construction X X X X X X X X X X X X X X X X

Solid waste removal X X X X 

PROJECT (LA-5-602-S): PUBLIC AWARENESS

PROGRAM: Public Information Program 

PRIORITY: 1 

ISSUE CATEGORIES: Agricultural discharges; nonpoint pollution sources; lack of fish 

and wildlife habitat; poor water quality and flocculent sediments; degradation of 

downstream lakes; low recreational and aesthetic values 

PROJECT OBJECTIVE: To increase public awareness of the degradation of Lake 

Apopka, the challenges of restoration, restoration successes, and the future restoration 

plans through communication with the public and news media 

SCOPE OF WORK: Continue to increase public awareness of Lake Apopka restoration 

issues. Communicate with the public and news media about the issues relating to the 

restoration of Lake Apopka. 

The Office of Communications and Governmental Affairs will continue the following 

activities: 

• Inform the public and news media about the progression and initiation of projects 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

168 

• Initiate and coordinate tours of Lake Apopka with the news media, elected officials, 

and stakeholders 

• Prepare and distribute news releases about project milestones, and follow up with 

the news media on coverage 

• Speak to community groups about projects 

• Develop public information materials as needed 

• Enhance SJRWMD’s Internet site with updated information 

• Publish stories in StreamLines on the status of projects 

• Coordinate public events to mark significant project milestones 

• Communicate issues to FOLA and other special interest groups 

The Education section of the Office of Communications and Governmental Affairs will 

continue to 

• Support Florida Yards, Neighborhoods and Ponds activities 

• Conduct stormwater pond education 

• Provide Environmental Landscaping Distance Learning classes to community 

colleges 

• Conduct Green Building seminars and CEU programs for contractors, builders, and 

home buyers 

• Implement the Watershed Action Volunteer program 

• Coordinate Community Water Festival with interested organizations 

• Implement the Legacy program 

• Provide teacher and facilitator training programs 

• Support Orange County Envirothon efforts 

• Expand intensive school programs 

• Provide presentations and training for staff of after school, extended day, park and 

recreation, and summer or camp programs 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will use 

communications with the public and news media to increase awareness and support for 

Lake Apopka restoration efforts. Information about the restoration projects will be 

communicated to the public and news media for the purpose of maintaining support 

for the Lake Apopka SWIM effort. 

STATUS: News media interviews, presentations to community groups, development of 

public information materials, coordination of public events, and tours of Lake Apopka 

restoration sites are an ongoing component of the restoration project. Tours are 

regularly provided to members of the news media, the public, dignitaries, and scientific 
Detail of Projects 

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delegations from around the United States and foreign countries interested in the 

restoration techniques being applied at Lake Apopka. Extensive public awareness 

efforts are also conducted through presentations to civic groups in Lake and Orange 

counties. Cooperative efforts with a residents’ group, FOLA, have resulted in volunteer 

shoreline plantings, school presentations, and media coverage. During 2001, students at 

eight Seminole County schools collected 16,000 socks to assist littoral zone planting 

efforts over the next two years. The sand-filled socks are tied to the base of plants, 

which are placed in the water. They anchor the plants in place long enough for their 

roots to become established. Eventually, the socks decompose and the sand falls to the 

bottom of the lake. SJRWMD provided a grant to FOLA in partial support of an 

educational video they developed. FOLA has formed a boat patrol to help SJRWMD 

monitor and track the development of submersed and other aquatic vegetation in the 

lake. The public outreach effort is an important method for SJRWMD to educate, 

inform, and address public issues. 

Reference materials available: 

• Lake Apopka fact sheet (2001) 

• Lake Apopka Marsh Flow-Way fact sheet (2001) 

• Littoral zone/sock drive overview (2001) 

• Lake Apopka tri-fold display (2000) 

• District recreation guide (2000) 

Public Awareness 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Tours, interviews, speaking 

engagements, etc. X X X X X X X X X X X X X X X X

Development of education materials X X X X X X X X X X X X X X X X

PROJECT (LA-5-603-S) LOCAL GOVERNMENT INFORMATION PROJECT

PROGRAM: Public Information Program 

PRIORITY: 1 

ISSUE CATEGORIES: Agricultural discharges; lack of fish and wildlife habitat; poor 

water quality and flocculent sediments; degradation of downstream lakes; low 

recreational and aesthetic values; nonpoint pollution sources 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

170 

PROJECT OBJECTIVE: To increase awareness among local, state, and federal elected 

officials and staff of the degradation of Lake Apopka, the challenges of restoration, 

restoration successes, and the future restoration plans 

SCOPE OF WORK: Continue a systematic approach to communicate the value of the 

Lake Apopka SWIM Plan to local, state, and federal government officials and encourage 

their participation as the lake restoration continues. Conduct on-site tours of the Lake 

Apopka restoration projects to demonstrate program successes. 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: This project will 

result in improved coordination with government officials to increase their awareness 

and support for Lake Apopka restoration efforts and the SWIM program. 

STATUS: Elected officials and staff at all levels of government are kept aware of project 

status. 

Activities by other agencies/interest groups: 

• FOLA initiated the formation of the Lake Apopka Basin Planning Initiative, a 

coordinated regional planning effort involving local elected officials, ECFRPC, 

SJRWMD, and other interested parties. 

• In February 2000, the Lake Apopka Basin Steering Committee was established to 

prioritize regional initiatives. The Initiative will serve to unite the six cities and two 

counties in addressing growth and development issues within the basin. Five areas 

were targeted to achieve an ecological and economical sustainable future (ECFRPC 

2000): 

 Shoreline protection 

 Greenways and trails 

 Viewsheds 

 Public Access 

 Natural setting 

• FOLA has begun an initiative to study and recommend a coordinated recreation 

planning report which focuses on a regional trails network. An intergovernmental 

management agreement was finalized during 2000 with the town of Oakland and 

the Oakland Nature Preserve for the disbursement of mitigation funds for the 

management of the Oakland Nature Preserve. 

Reference materials available: 
Detail of Projects 

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• Lake Apopka: A basinwide planning initiative (ECFRPC, 2000) 

• Lake Apopka fact sheet (2001) 

• Lake Apopka Marsh Flow-Way fact sheet (2001) 

• Littoral zone/sock drive overview (2001) 

• Lake Apopka tri-fold display (2000) 

• District recreation guide (2003) 

Local Government Information Project 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Tours, speaking engagements, etc. X X X X X X X X X X X X X X X X

Coordinate with the Lake Apopka 

Basin Steering Committee X X X X X X X X X X X X X X X X

SWIM plan public hearing X

PROJECT (LA-3-701-S): MARSH FLOW-WAY LAND ACQUISITION

PROGRAM: Land Acquisition 

PRIORITY: Completed 

ISSUE CATEGORIES: Agricultural discharges; lack of fish and wildlife habitat; poor 

water quality and flocculent sediments; degradation of downstream lakes; low 

recreational and aesthetic values 

PROJECT OBJECTIVE: To acquire necessary muck farm lands and other agricultural 

lands in support of the marsh flow-way 

SCOPE OF WORK: Attain and review three appraisals. Negotiate with land owners. 

Prepare inventory and environmental site assessment of the property. Prepare closing 

documents. Acquire property. 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: This project resulted 

in acquisition of agricultural lands, upon which the demonstration marsh and Phase I of 

the marsh flow-way have been constructed. Future cells D through H are kept in a 

flooded condition to create wetland habitat, eliminate fertilizer and pesticide 

application, and reduce pumping of water to the Apopka-Beauclair Canal. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

172 

SUMMARY: A total of 2,164 ha (5,343 ac) of former agricultural lands west of the 

Apopka-Beauclair Canal were acquired from 1988 to 1992 to support the Marsh FlowWay Project. Parcels purchased include Hooper Farms, Duda (Clay Island), 

Brady/RICO, Howard (Clay Island), Duda/Whittle, Wilkinson-Cooper Farm, and CC 

Ranch. An additional 198 ha (490 ac) west of the canal (Keen, Blunt, and Boyd-Davis 

properties) were obtained from 1990 through 1995 to support the restoration project. 

Five million dollars was appropriated in both 1988 and 1989 through the State 

Infrastructure Trust Fund and in 1990 by Preservation 2000 for land acquisition by 

SJRWMD to facilitate the Lake Apopka restoration efforts. 

PROJECT (LA-3-704-S): NORTH SHORE LAND ACQUISITION

PROGRAM: Land Acquisition 

PRIORITY: Priority 1 

ISSUE CATEGORIES: Agricultural discharges; lack of fish and wildlife habitat; poor 

water quality and flocculent sediments; degradation of downstream lakes; low 

recreational and aesthetic values 

PROJECT OBJECTIVE: To plan, evaluate, prioritize, and acquire properties within the 

former Lake Apopka floodplain wetlands to provide conservation and preservation 

lands 

SCOPE OF WORK: Evaluate, prioritize, and acquire critical habitats in the NSRA as 

additions to the wetlands restoration effort or as preservation projects. Annually assess 

acquisition needs comprehensively within resource-based planning areas and 

watershed subbasins for the update to the Florida Forever work plan. Actual 

acquisitions will be dependent upon availability of funding. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project will provide a 

basis for additional land acquisitions critical to the restoration of the lake and the 

preservation efforts in the basin. Budget and time schedules will be developed as 

necessary. 

STATUS: Legislation in 1996 provided the direction to pursue a total farm buyout and 

$20 million toward that goal. The Governing Board approved purchase of the 1,285-ha 

(3,173-ac) Jem Farm, owned by A. Duda and Sons, Inc., in December 1996. The closing 

date was April 18, 1997. SJRWMD signed an agreement with USDA to receive up to $26 

million in matching land acquisition funds through the WRP for the NSRA. This money 
Detail of Projects 

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comprised part of the funding for Jem Farm in conjunction with Save Our Rivers and 

Conservation and Recreation Lands funding. 

During the 1997 legislative year, an additional $45 million was appropriated for 

purchasing additional agricultural lands. Through the end of 1997, the Governing 

Board had approved Zellwin Farms’ 2,128 ha (5,254 ac) and a total of 1,818 ha (4,488 ac) 

within ZDWCD for purchase. The properties include Lust Farms, Lust and Long 

Precooler, Stroup Farms, Clonts Farm, Crakes and Sons, Grower’s Precooler, Beall 

Farms, and Long Farms. The closing dates were August through October 1998. 

The final farmlands (381 ha, or 940 ac) within the ZDWCD were purchased in August 

1999. Bringing the land into public ownership completes SJRWMD acquisition of the 

Lake Apopka muck farms. As a result of state legislation in 1996, 1997, and 1998, 

SJRWMD and WRP have brought approximately 5,636 ha (13,900 ac) into public 

ownership within the NSRA. 

Reports

[SJRWMD] St. Johns River Water Management District. 2000. Land acquisition and 

management 2000 five-year plan. Palatka, Fla. 

———. 2001. Florida Forever work plan. Palatka, Fla. 

North Shore Acquisition 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Parcel evaluation and appraisal of 

adjoining properties X X 

Purchase negotiation X X X 

Governing Board purchase approval X X X X 

PROJECT (LA-6-802-S): IMPLEMENTATION OF RESTORATION AND 

MANAGEMENT TECHNIQUES

PROGRAM: Technical Support 

PRIORITY: 1 

ISSUE CATEGORY: All issues 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

174 

PROJECT OBJECTIVE: To provide overall analysis and coordination of diagnostic, 

feasibility, regulatory, planning, land acquisition, public information, and restoration 

projects 

SCOPE OF WORK: Review, analyze, and integrate results of diagnostic, feasibility, and 

pilot restoration studies. Coordinate technical studies with regulatory, planning, public 

information, and land acquisition projects. Recommend ecologically sound and costeffective restoration and management techniques as these are evaluated. Identify goals 

and strategies for regulatory activity concurrent with restoration. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: This project represents the 

integration of the Lake Apopka SWIM Program to implement restoration, management, 

and regulatory strategies. 

STATUS: Thirteen of the 16 diagnostic and feasibility studies have been completed. 

These initial projects were vital in shaping the direction of the Lake Apopka Restoration 

Plan. Presently, the major effort is focused on the restoration program. Phase I of the 

marsh flow-way is now constructed, and management plans are being developed for 

the restoration of acquired farmland. In addition, rough-fish harvesting and littoral 

zone restoration continues. The integration of these diverse programs will be vital to the 

attainment of the Lake Apopka restoration goals. 

Reports

Battoe, L.E., E.F. Lowe, M.F. Coveney, and D.L. Stites. 1994. Determining restoration goals for 

Lake Apopka. Lake Reserv. Manage. 9(2):54. 

Battoe, L.E., M.F. Coveney, E.F. Lowe, and D.L. Stites. 1999. The role of phosphorus reduction 

and export in the restoration of Lake Apopka, Florida. In Phosphorus biogeochemistry in 

subtropical ecosystems, K.R. Reddy, G.A. O’Connor, and C.L. Schelske, eds., 511–526. Boca 

Raton, Fla.: Lewis Publishers. 

Conrow, R., W. Godwin, M.F. Coveney, and L.E. Battoe. 1989. SWIM plan for Lake Apopka. 

St. Johns River Water Management District, Palatka, Fla. 

Conrow, R., W. Godwin, M.F. Coveney, and L.E. Battoe. 1993. SWIM plan for Lake Apopka. 

St. Johns River Water Management District, Palatka, Fla. 

Coveney, M.F., D.L. Stites, E.F. Lowe, L.E. Battoe, and R. Conrow. 2001. Nutrient removal from 

eutrophic lake water by wetland filtration. Ecological Engineering (submitted). 
Detail of Projects 

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Dean, H., and E. Lowe. 1998. The restoration program for Lake Apopka, Florida. Vol. 5, 313–

316. In Proceedings of Water Environment Federation 71st Annual Conference and Exposition, 

October 1998, Orlando, Fla. 

Fonyo, C.M., and W.G. Boggess. 1989. Coordination of public and private action: A case study 

of lake restoration. Water Resources Bul. 25(2):309–317. 

Lowe, E.F., L.E. Battoe, M.F. Coveney, and D.L. Stites. 1992. Particulate phosphorus removal via 

wetland filtration: An examination of potential for hypertrophic lake restoration. Environ. 

Manage. 16(1):67–74. 

———. 1994. The restoration strategy for Lake Apopka, Florida. Lake Reserv. Manage. 9(2):116–

117. 

———. 1997 (in preparation). Determination of restoration goals for Lake Apopka, a culturally 

eutrophic lake. St. Johns River Water Management District, Palatka, Fla. 

———. 1999. Setting water quality goals for restoration of Lake Apopka: Inferring past 

conditions. Lake Reserv. Manage. 15(2):103–120. 

Lowe, E.F., D.L. Stites, and L.E. Battoe. 1989. Potential role of marsh creation in restoration of 

hypertrophic lakes. In Constructed wetlands for wastewater treatment: Municipal, industrial and 

agricultural, D.A. Hammer, ed., 710–717. Proceedings from the First International 

Conference on Constructed Wetlands for Wastewater Treatment. Chelsea, Mich.: Lewis 

Publishers. 

[SJRWMD] St. Johns River Water Management District. 2001. Florida Forever work plan. 

Palatka, Fla. 

Implementation of Restoration and Management Techniques 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Provide technical support X X X X X X X X X X X X X X X X

PROJECT (LA-6-803-S): RESTORATION MONITORING AND ANALYSIS

PROGRAM: Technical Support 

PRIORITY: 1 

ISSUE CATEGORY: All issues 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

176 

PROJECT OBJECTIVE: To implement a monitoring program during restoration 

activities and in the post-restoration period, and to assess restoration progress, facilitate 

adaptive management, and track performance measures 

SCOPE OF WORK: Monitor physical, chemical, and biological conditions in Lake 

Apopka and the NSRA. Depending on monitoring site, include meteorological 

conditions, water quality, phytoplankton and zooplankton composition, invertebrate 

community structure, fish and wildlife species composition and abundance, and 

vegetation development in the littoral zone and in restored wetlands. Design and 

execute restoration monitoring to quantify the effects of restoration techniques and to 

collect data on performance measures for the project. Develop and implement a 

monitoring program for agricultural chemical residues remaining in the soils of the 

NSRA. Incorporate these data into districtwide relational databases and spatial 

databases. 

RELATIONSHIP TO FOCUS AND INTENT OF SWIM ACT: During and following the 

implementation of restoration efforts in Lake Apopka, a monitoring program is 

necessary to measure the performance of restoration projects and to indicate any need 

to modify restoration techniques through time (adaptive management). 

STATUS: SJRWMD monitoring of water quality and nutrient loading continues at 

several sites in Lake Apopka, the Apopka-Beauclair Canal, and newly acquired 

farmlands. Monitoring is required to measure the effectiveness of efforts to reduce 

nutrient loading to the lake and to improve lake water quality. Since mid-1995, there 

has been a significant decline in phosphorus and chlorophyll in the lake. At the same 

time, the resulting increased transparency (light availability) likely is responsible for the 

reappearance of submersed aquatic plants within the lake, a key indicator for 

restoration progress. Analysis of phytoplankton samples collected over the past several 

years was started to assess changes in the algal community related to the changes in 

water quality. Monitoring and analysis of fish populations are required as part of 

SJRWMD’s permit to harvest rough fish and provide important information on success 

of the harvest and on changes in ecologically and economically important fish stocks. 

SJRWMD staff and volunteers from FOLA have begun a project to monitor vegetation 

development around the lake. Resident volunteers patrol the lake, noting the location 

and types of submersed vegetation that they find. This information is provided to 

SJRWMD staff, who accurately locate and quantify the vegetation patches and monitor 

changes in those patches. The data are then mapped, which provides a history of 

vegetation development in a spatial database as the restoration continues. The work 

also provides information on the location of invasive exotic vegetation, particularly 
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hydrilla. Early detection of hydrilla is essential if SJRWMD is to continue to be 

successful in controlling it at very low levels. 

As part of the investigation into the cause of the bird deaths on the Lake Apopka NSRA 

in 1998 and 1999, SJRWMD has sampled the soils of the entire NSRA and various 

animal tissues. This work led to the development of several databases to manage and 

analyze contaminant data from soil, sediment, and tissue samples and necropsy data 

from a variety of sources including SJRWMD, UF, FDEP, EPA, USFWS, and various 

contractors. 

Reports

Havens, K.E., H.J. Carrick, E.F. Lowe, and M.F. Coveney. 1999. Contrasting relationships 

between nutrients, chlorophyll a, and Secchi transparency in two shallow subtropical lakes, 

Lakes Okeechobee and Apopka (Florida, USA). Lake Reserv. Manage. 15(4)298–309. 

Lowe, E.F., L.E. Battoe, M.F. Coveney, C.L. Schelske, K.E. Havens, E.R. Marzolf, and K.R. 

Reddy. 2001. The restoration of Lake Apopka in relation to alternative stable states: An 

alternative view to that of Bachmann et al. (1999). Hydrobiologia 448:11–18. 

Restoration Monitoring and Analysis 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Water quality sampling and 

nutrient budgets X X X X X X X X X X X X X X X X

Vegetation monitoring and 

analysis X X X X X X X X X X X X X X X X

Contaminant monitoring and 

analysis X X X X X X X X X X X X X X X X

Fish monitoring X X X X X X 

Bird monitoring X X X X X X X X X X X X X X X X

PROJECT (LA-6-804-S): OVERALL PROGRAM MANAGEMENT

PROGRAM: Technical Support 

PRIORITY: 1 

ISSUE CATEGORY: All issues 
SWIM Plan for Lake Apopka 

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178 

PROJECT OBJECTIVE: To provide overall management of the Lake Apopka SWIM 

program 

SCOPE OF WORK: Provide managerial and secretarial support and interagency 

coordination. Develop quarterly and annual reports on the Lake Apopka SWIM Project. 

Prepare, review, and submit revisions of the Lake Apopka SWIM Plan for approval in 

accordance with statutory requirements. Prepare reports to FDEP and other agencies as 

needed. Participate in SJRWMD planning, budgeting, and progress evaluation and 

reporting activities. 

RELATIONSHIP TO FOCUS AND INTENT OF THE SWIM ACT: This project will 

result in successful coordination and management of the Lake Apopka restoration 

effort. 

STATUS: Managerial and secretarial support and interagency coordination was 

provided for the Lake Apopka SWIM effort. Reports to FDEP and other agencies were 

prepared as required. The Lake Apopka SWIM Plan was extensively revised in 1989 

with review by FDEP, FWC, other state agencies, and local governments. Update of 

schedules and progress shown in the SWIM Plan was accomplished through quarterly 

and annual reporting. A draft triennial revision of the Lake Apopka SWIM Plan was 

completed in October 1992 for agency review, and the SJRWMD Governing Board gave 

its final approval to the plan in January 1993. 

SJRWMD has recently implemented a project delivery system and project control 

system to improve the implementation of projects. The benefits of these systems include 

improved budgeting, scheduling, tracking, and quality. 

Reports

Battoe, L.E., D. Walker, and J. Modica. 1988. Interim SWIM Plan for Lake Apopka. St. Johns 

River Water Management District, Palatka, Fla. 

Conrow, R., W. Godwin, M.F. Coveney, and L.E. Battoe. 1993. SWIM plan for Lake Apopka. St. 

Johns River Water Management District, Palatka, Fla. 

[SJRWMD] St. Johns River Water Management District. 1999. Lake Apopka Restoration Project: 

Wildlife impacts and progress toward remediation. A report to the Honorable Governor Jeb 

Bush and the Legislature of the state of Florida. Palatka, Fla. 
Detail of Projects 

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Overall Program Management 

Time Schedule Activity FY 02–03 FY 03–04 FY 04–05 FY 05–06 

Report compilation and review X X X X X X X X X X X X X X X X

Overall program management 

coordination X X X X X X X X X X X X X X X X
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

180 
Summary of Project Funding 

St. Johns River Water Management District

181 

SUMMARY OF PROJECT FUNDING

INTRODUCTION

Enactment of the Lake Apopka Restoration Act in 1985 created the impetus to accelerate 

the development of an “environmentally sound, economically feasible method for 

restoring Lake Apopka to a Class III water body” (Appendix A). The legislative 

directive also provided $2,265,000 for FY 1985–86 to initiate comprehensive monitoring 

and research efforts. The SWIM Act of 1987 further spurred the planning and 

implementation of the restoration. During the early years of the program, much of the 

funding was directed to diagnostic projects conducted to evaluate the status of the 

water body and to reach a clearer understanding of the causes of existing problems. As 

the diagnostic and feasibility projects were completed, the emphasis of the program 

was refocused on restoration, regulatory, and land acquisition projects. 

A detailed list of the project budgets by fiscal year is in Table 7. Staff salaries are 

included except within projects in the public information, planning, and land 

acquisition program areas. The salaries for these programs are contained within 

budgets outside of this document. Table 8 details land acquisition costs. 

FUNDING SOURCES

The restoration of a water body the magnitude of Lake Apopka requires a financial 

participation by many local, state, regional, and federal agencies. A partial listing of 

agencies participating in the restoration of Lake Apopka follows. 

Federal Participation 

EPA—EPA contributed $1 million in 1997 toward construction of the marsh flow-way. 

USDA—In 1997, SJRWMD received a commitment of $26 million from the NRCS WRP 

for the purchase of farm properties (Table 8). Approximately $18.5 million of the WRP 

funds has been spent for acquisition of the farm properties in the NSRA. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

182 

Table 7. Estimated capital and operating funding required for Lake Apopka SWIM projects, FY 2002–

2006 

Title FY 02-03 FY 03-04 FY 04-05 FY 05-06 

Diagnostic Program 

External Nutrient Budget $60,815 $27,704 $14,199 $14,553 

Fishery 0 66,926 0 0 

Program total 60,815 94,630 14,199 14,553 

 

Feasibility Program 

Drawdown and Lake Level Fluctuation 20,272 20,778 21,298 14,553 

Program total 20,272 20,778 21,298 14,553 

 

Restoration Program 

Marsh Flow-Way Restoration 483,930 540,857 3,298,474 380,132 

Rough Fish Harvesting 213,514 356,926 282,099 207,277 

Wetland Restoration 4,347,062 1,863,970 4,013,970 3,785,623 

Littoral Zone Restoration 40,543 51,557 45,496 46,384 

Program total 4,418,184 2,761,753 7,640,039 4,419,416 

 

Regulatory Program 

Non Point Source Pollution Control 13,514 6,926 7,099 7,277 

Program total 13,514 6,926 7,099 7,277 

 

Planning Program 

District Water Management Plan* 

Local Government Comp. Plan Review* 

Land Management Plan and 

Implementation 1,506,666 347,516 189,396 225,266 

Program total 1,506,666 347,516 189,396 225,266 

 

Public Information Program 

Public Awareness Program* 

Local Government Information Project* 

Program total 

 

Land Acquisition Program 

North Shore Land Acquisition* 250,000 0 0 0 

Program total 250,000 0 0 0 

 

Technical Support Program 

Restoration and Management Techniques 40,543 41,557 42,596 43,660 

Restoration Monitoring and Analysis 214,130 224,670 237,787 250,981 

Program total 254,673 266,227 280,383 294,641 

 

Overall Program Management 

Overall Program Management 108,115 110,818 106,489 101,874 

Program total 108,115 110,818 106,489 101,874 

Overall totals 6,682,239 3,608,648 8,258,903 5,077,580 

*The salaries for these projects are contained within budgets outside of the program. 
Summary of Project Funding 

St. Johns River Water Management District

183 

Table 8A. St. Johns River Water Management District land acquisition in the Lake Apopka Basin as of 

December 20, 2002 

Property Acquired Funding Mechanism Acres Date 

Acquired Cost ($) 

Marsh Flow-Way and Adjoining Properties 

Duda/Clay Island Legislative appropriation 1,859.9 11/30/88 4,500,000 

Brady/RICO Legislative appropriation 198 1/2/90 83,197 

Hooper Farms Legislative appropriation 1,363.1 3/28/90 4,800,000 

Hooper Farms Legislative appropriation 200 10/27/88 200,000 

Howard Legislative appropriation 5 8/6/90 70,000 

Duda/Whitle Legislative appropriation 1,100 8/30/90 2,950,000 

Wilkinson-Cooper Farm P2000 365 5/15/92 1,279,145 

C.C. Ranch P2000 255 5/15/92 669,296 

Boyd-Davis P2000 181.44 8/30/95 474,128 

Wilkinson Ad valorem 5.35 1/26/01 18,725 

Subtotal 5,532.79 15,044,491 

North Shore Restoration Area and Adjoining Properties 

Keen Ranch P2000 256 12/9/93 434,384 

Blunt P2000 53 5/29/95 106,000 

Duda/Jem Farm SOR, CARL, and WRP 3,172.89 4/18/97 20,032,495 

Zellwin Farms SOR, WRP, P2000, and leg. app. 5,168.69 8/21/98 32,968,815 

Long Farms, Inc. SOR, WRP, P2000, and CARL 1,016.58 10/6/98 8,926,160 

Clarence Beall P2000 and WRP 310.49 9/14/98 1,316,111 

Clonts Farm P2000 and WRP 642.74 9/14/98 4,200,000 

Lust Farms, Inc. P2000, WRP, and leg. ap. 1,507.51 9/14/98 9,211,900 

Stroup Farms, Inc. P2000 and WRP 414.43 9/14/98 1,935,377 

Lust and Long Precooler P2000 13.37 9/25/98 1,274,465 

Growers Precooler, Inc. P2000 17.23 10/14/98 3,377,175 

Crakes and Sons, Inc. P2000 and WRP 508.84 10/6/98 2,639,814 

Grinnell, Hensel and Rogers, 

B. Potter and K. Rice, M. Rice Legislative appropriation 829 8/20/99 9,333,550 

Hickerson Leg. ap., SOR, and ad valorem 119.8 8/20/99 3,305,075 

Baumgardt Lake Apopka lease revenues 0.2 9/9/99 20,000 

Freeman Lake Apopka lease revenues 11.4 9/9/99 30,000 

Wallace Carrot, Inc. Lake Apopka lease revenues — 4/21/99 155,000 

Teddy Smith Lake Apopka lease revenues 35.66 3/22/00 108,550 

M.E. Marsell Lake Apopka lease revenues 1.99 6/29/00 7,960 

J. and F.M. Marsell Lake Apopka lease revenues 11.07 6/29/00 44,280 

S. Marsell Lake Apopka lease revenues 19.98 6/29/00 52,947 

Bates Lake Apopka lease revenues 8.49 7/21/00 213,000 

NAPA Lake Apopka lease revenues 34.86 8/30/00 258,222 

Davison Lake Apopka lease revenues 9.13 3/30/01 36,148 

Schaffer Lake Apopka lease revenues 12.86 5/17/01 38,580 

World Foliage Resources 

Property exchange for Grinnell 

Precooler 8.00 11/26/01 (79,193)

Grinnell Precooler Property for World Foliage Resources -5.6 11/26/01 Exchange 

Strickland Ad valorem 19.09 2/1/02 55,173 

World Foliage Resources Beltway mitigation 60.32 9/27/02 328,000 

Keen Ranch addition P2000 49.6 12/19/02 171,312 

Langley Beltway mitigation 58 12/20/02 141,370 

Subtotal 14,366.55 100,642,670 

 Total 19,895.90 115,687,161 

Note: — = purchased infrastructure only, no property 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

184 

Table 8B. Properties under contract (not closed) as of December 20, 2002 

Property Under Contract Funding Mechanism Acres Estimated 

Closing Date 

Total Cost 

($) 

Shortz Beltway mitigation 52.1 Unknown 515,000 

Holt Land swap 9.4 Unknown 0 

 Total (anticipated) 61.5 515,000 

State Participation 

State Infrastructure Trust Fund—Five million dollars was appropriated in both 1988 

and 1989 for land acquisition in the Lake Apopka Basin. 

Preservation 2000 (P2000)—Five million dollars was appropriated to SJRWMD for land 

acquisition in 1990 for Lake Apopka restoration. The General Appropriations Act for FY 

1997–98 appropriated $45 million to SJRWMD for purchase of farmlands within the 

basin with $20 million of that total routed through the P2000 program and $25 million 

from FDEP general revenues. 

Conservation and Recreation Lands (CARL) Trust Fund—The General Appropriations 

Act for FY 1996–97 appropriated $12 million to SJRWMD from CARL (Appendix A). 

SJRWMD was directed to use $8 million from its share of funds from the Water 

Management Lands Trust Fund (WMLTF) or from funds derived from revenue bonds 

as a revenue source for the purchase of farm lands. 

SWIM trust funds—Created by the enactment of the 1987 SWIM Act, SWIM funds are 

limited to the costs of detailed planning for and implementation of programs prepared 

for priority surface waters. They are intended to enhance existing funding and to 

produce improved environmental results, not to replace existing programs. SWIM trust 

funds required at least a 20% match from the water management districts for FY 1990–

91 and a 40% match for FY 1992–97 from ad valorem revenues, operations funds, cash 

grants, future state funding, eligible sources of district matching funds, and annual 

allocation of funds to the districts. 

WMLTF—Created through the Save Our River legislation (Section 373.59, FS), the fund 

is to be used for the purposes of land acquisition, management, and maintenance, and 

capital improvements. Through Specific Appropriation 1205 in Chapter 99-226, Laws of 

Florida, the state Legislature provided $11 million for the purchase of farms from the 

WMLTF. 
Summary of Project Funding 

St. Johns River Water Management District

185 

Florida Forever—The initial five-year SJRWMD Florida Forever Work Plan (January 

2002) allocates $7.5 million for works in the NSRA (FY 2003–2004). 

Central Florida Beltway—In September 1998, mitigation for the environmental impacts 

of the Western Beltway SR-429 Part A provided $2 million for the construction of the 

Lake Apopka Marsh Flow-Way. In September 2001, mitigation for an additional 

segment of the Beltway, SR-429 Part C Phase I, provided $2,077,980 for Lake Apopka 

land acquisition, restoration, and water quality enhancements. 

Local Participation 

Ad valorem taxes—SJRWMD was given the authority under Section 353.503, FS, to levy 

taxes up to a 0.6 millage rate, commencing in 1977. 

Local government—Lake County and the Lake County Water Authority committed up 

to $1 million in matching funds toward the construction of the marsh flow-way, Phase I, 

during 1998–99. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

186 
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Stites, D.L., M. Coveney, L. Battoe, E. Lowe, and V. Hoge. 2001 (draft). An external phosphorus 

budget for Lake Apopka. Technical memorandum. St. Johns River Water Management 

District, Palatka, Fla. 

Sykes, P.W., Jr., and G.S. Hunter. 1978. Bird use of flooded agricultural fields during summer 

and early fall and some recommendations for management. Florida Field Naturalist 6:36–43. 

[UF] University of Florida. 2001. Florida statistical abstract 2001. Bureau of Economic and 

Business Research, Warrington College of Business Administration. Gainesville, Fla. 

[USDA] U.S. Department of Agriculture. 2001. Lake Apopka North Shore Restoration Area 

biological assessment and interim restoration plan for Duda property. Natural Resources 

Conservation Service. Gainesville, Fla. 

[USFWS] U.S. Fish and Wildlife Service. 2001. Threatened and endangered species system 

(TESS). Listing by state and territory as of 1/30/01. Available at 

http://ecos.fws.gov/webpage/webpage_use_lists.html. 

———. 2002. Biological opinion for the interim restoration plan for the Duda sub-east property 

located at the North Shore Restoration Area of Lake Apopka (Log No. 02-650), Orange 

County, Florida. Jacksonville, Fla. 

[USGS] U.S. Geological Survey. 2002. Daily streamflow for Apopka-Beauclair Canal near 

Astatula. Available at http://waterdata.usgs.gov. 

Woodward, A.R., H.F. Percival, M.L. Jennings, and C.T. Moore. 1993. Low clutch viability of 

American alligators on Lake Apopka. Florida Scientist 56(1):52–64.
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Appendix A 

St. Johns River Water Management District

197 

APPENDIX A—LEGISLATION AND RULES

The following documents were reproduced from scanned images using optical 

character recognition technology. Every effort was made to ensure that these are 

accurate reproductions of the original documents, but in some cases, the documents 

may appear different from the original forms. In addition, some non-pertaining sections 

were removed to conserve resources. The laws are now incorporated into Sections 

373.451-373.459, SWIM legislation, and Section 373.461, Lake Apopka improvement and 

management of the Florida Statutes (FS 2000). 

1. Lake Apopka Restoration Act Chapter 85-148, Laws of Florida.....................................198 

2. 1987 SWIM Legislation Chapter 87-97, Laws of Florida ..................................................201 

3. 1996 Lake Apopka Legislation Chapter 96-207, Laws of Florida ...................................213 

4. 1997 Lake Apopka Legislation Chapter 97-81, Laws of Florida .....................................217 

5. Rule No. 40C-4.091, F.A.C. (establishing phosphorus criterion for Lake Apopka) 

pursuant to the mandate of Chapter 96-207, Laws of Florida.........................................223 

6. Proposed Rule Revisions to Sections 40C-4, 40C-41, 40C-42, and 40C-44, F.A.C., and 

Related Applicant Handbooks: Management and Storage of Surface Waters 

Drainage Basins and Phosphorus Limitations (FAW 2002) ..........................................229 

7. Notices of Change to the proposed rule ..........................................................................245 
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CHAPTER 85-148 

Committee Substitute for House Bill No. 251 

An act relating to the preservation of Florida’s lakes; amending s. 403.0615, F.S.; renaming the 

“Water Resources Restoration and Preservation Act” as the “Lake Restoration Act”; 

establishing a program to assist in the restoration and protection of certain state lakes; 

providing criteria for allocation of restoration funds; providing for a trust fund; providing 

priority for Lake Apopka and requiring submission of a restoration and management plan 

therefore; providing an appropriation; providing an effective date. 

Be It Enacted by the Legislature of the State of Florida: 

Section 1. The Legislature hereby directs the St. Johns River Water Management District, in conjunction 

with the Department of Environmental Regulation, Game and Fresh Water Fish Commission, Lake 

and Orange Counties, and the Lake Apopka Restoration Council to initiate a pilot project for Lake 

Apopka. The purpose of the project is to identify an environmentally sound, economically feasible 

method for restoring Lake Apopka to a Class III water body. 

Section 2. (1) There is created within the St. Johns River Water Management District the Lake Apopka 

Restoration Council. The council shall consist of eleven members as follows: a scientific 

representative from the St. Johns River Water Management District, a scientific representative from 

the Game and Fresh Water Fish Commission, a scientific representative from the Department of 

Environmental Regulation, and a scientific representative from Orange County, each to be 

appointed by their respective agencies; a nonagricultural lake front property owner; two 

representatives from the lake front agricultural community, each representing predominant but 

different agricultural industries, an environmental engineer, a representative of the sportsfishing 

industry, a representative of a municipality abutting Lake Apopka from Orange County and a 

representative of a municipality abutting Lake Apopka from Lake County, each to be appointed by 

the Governor. The council shall be advisory to the St. Johns River Water Management District 

governing board. 

(2) Immediately after their appointment, the members of the council shall meet and organize by 

electing a chairman, a vice chairman, and a secretary, whose terms shall be for 3 years each. 

Council officers may not serve consecutive terms. Council members representing state agencies 

shall not have voting powers; however, at the discretion of the council they may serve in the 

capacity of chairman. 

(3) The council shall meet at the call of its chairman, at the request of a majority of its members, or 

at the request of the St. Johns River Water Management District governing board chairman. 

Section 3. The Lake Apopka Restoration Council shall have the powers and duties to: 

(1) Review studies and data specifically related to lake restoration techniques and advise the district 

governing board of approaches to be considered for restoration of Lake Apopka. 

(2) Make a recommendation to the district governing board for a Lake Apopka restoration program. 
Appendix A 

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(3) Report directly to the Legislature before November 25 of each year with a Lake Apopka 

restoration progress report and any recommendations for the forthcoming fiscal year. 

Section 4. Members of the Lake Apopka Restoration Council shall receive no compensation for their 

services but are entitled to be reimbursed for per them and travel expenses as provided in s.112.061, 

Florida Statutes. 

Section 5. The St. Johns River Water Management District governing board shall specify tasks which are 

to be undertaken by the district, the Department of Environmental Regulation, pertinent local 

governments, and the Game and Fresh Water Fish Commission in order to initiate the pilot project 

for Lake Apopka. The governing board shall: 

(1) Conduct extensive water sampling of the lake and its associated tributaries to determine the 

existing water quality and to determine the long term effects of nutrient loading from 

agricultural activities. 

(2) Evaluate the restoration of a portion of floodplain marsh between Lake Apopka and the 

Apopka-Beauclair Lock by allowing sheetflow of waters prior to their entrance to the ApopkaBeauclair Canal. 

(3) Develop a nutrient budget for the lake to ensure that appropriate regulatory efforts are 

instituted with respect to nutrient loading. 

(4) Examine techniques which may be used to modify the existing physical and biological 

characteristics of the lake. 

(5) Conduct a feasibility study to determine the effects of diking-off and restoring the littoral zone 

of the lake to enhance sportfish production. 

(6) Implement and evaluate a program to demonstrate the feasibility of utilizing water hyacinths to 

extract excessive nitrogen and phosphorus from the sediment and water columns of the lake. 

(7) Implement and evaluate a program to demonstrate the feasibility of recreating a marsh along the 

lake-shoreline using muck dredged from the lake bottom, and 

(8) From funds appropriated by this act, expend up to $100,000 to contract for a feasibility study on 

the recycling of muck from Lake Apopka. 

The St. Johns River Water Management District shall provide the staff for the Lake Apopka Restoration 

Council while engaged in carrying out the provisions of this act. 

Section 6. There is hereby appropriated to the Department of Environmental Regulation for the St. Johns 

River Water Management District the following sums of money for fiscal year 1985-1986 to carry out 

the provisions of this act: 

(1) The sum of $765,000 for fiscal year 1985-1986 from the water Resources Restoration and 

Preservation Trust Fund within the Department of Environmental Regulation to implement the 

provisions outlined in subsections (1) through (5) of section 5. 
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(2) The sum of $1.5 million for fiscal year 1985-1986 from the Aquatic Plant Control Trust Fund 

within the Department of Natural Resources to implement the provisions outlined in subsection 

(6) of section 5. 

Section 7. It is the intent of the Legislature that the St. Johns River Water Management District shall, 

through competitive bid, award contracts to implement the provisions of this act. 

Section 8. This act shall take effect July 1, 1985 or upon becoming a law, whichever occurs later. 

Approved by the Governor June 17, 1985. 

Filed in Office Secretary of State June 17, 1985. 
Appendix A 

St. Johns River Water Management District

201 

CHAPTER 87-97 

Committee Substitute for House Bill No. 1350 

An act relating to natural resources; creating the “Surface Water Improvement and Management 

Act”; providing legislative findings and intent; providing for the developing of lists of 

prioritized water bodies of regional or statewide significance and for the design and 

implementation of surface water improvement and management plans and programs by the 

state’s five regional water management districts; providing for participation by state 

agencies, local governments, and advisory committees; providing for the review of surface 

water improvement and management plans by certain state agencies and for the review of 

agency rules; providing for the implementation of surface water improvement and 

management plans and programs and making funds available; providing for the creation 

within the Department of Environmental Regulation of the Surface Water Improvement 

and Management Trust Fund and providing procedures for the administration of the Trust 

Fund; providing for a program to protect the water quality of Lake Okeechobee; creating 

the Lake Okeechobee Technical Advisory Council; Providing for limitations on the 

diversion of specified waters; establishing a program for the improvement and 

management of the Lower St. Johns River; creating the Duval County Water Quality 

Council; establishing areas of jurisdiction and creating an approval process; amending 

section 5 of chapter 85-148, Laws of Florida; providing tasks for the pilot project for Lake 

Apopka; amending section 7 of chapter 85-148, Laws of Florida; providing for competition 

among contractors for projects; directing the Department of Environmental Regulation to 

conduct a study to evaluate the existing classification systems for waters of the state; 

amending s. 373.503, F.S.; removing certain restrictions on the use of millage levied by the 

St. Johns Water Management District; changing the distribution of certain taxes for district 

and basin purposes; amending ss. 161.021, 161.041, 161.053, 161.054, 161.091, 161.101, 

161.141, 161.161, 373.026, F.S.; providing definitions; prohibiting the Department of Natural 

Resources from issuing permits for certain construction or excavation except in specified 

circumstances; establishing criteria for local coastal construction zoning and building codes; 

providing for permits when liens are imposed on the property; establishing property rights 

of the state; renaming the Erosion.Control Trust Fund; authorizing the department to use 

funds from the Beach Management Trust Fund to pay certain costs of specified beach 

management projects; providing procedures for approval of projects; providing for powers 

and duties of the Department of Environmental Regulation; providing for a report on public 

access to sandy beaches; making funds available from the State Infrastructure Trust Fund; 

providing an effective date. 

Be It Enacted by the Legislature of the State of Florida: 

Section 1. Short title; legislative findings and intent.— 

(1) Sections 1 through 6 of this act may be cited as the “Surface Water Improvement and 

Management Act.” 

(2) Legislative intent.—The Legislature finds that the water quality of many of the surface waters of 

the state has been degraded, or is in danger of becoming degraded, and that the natural systems 

associated with many surface waters have been altered so that these surface waters no longer 

perform the important functions that they once performed. These functions include: 
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(a) Providing aesthetic and recreational pleasure for the people of the state; 

(b) Providing habitat for native plants, fish, and wildlife, including endangered and threatened 

species; 

(c) Providing safe drinking water to the growing population of the state; and 

(d) Attracting visitors and accruing other economic benefits. 

(3) The Legislature finds that the declining quality of the state’s surface waters has been detrimental 

to the public’s right to enjoy these surface waters and that it is the duty of the state, through the 

state’s agencies and subdivisions, to enhance the environmental and scenic value of surface 

waters. 

(4) The Legislature finds that factors contributing to the decline in the ecological, aesthetic, 

recreational, and economic value of the state’s surface waters include: 

(a) Point and nonpoint source pollution; and 

(b) Destruction of the natural systems which purify surface waters and provide habitats. 

(5) The Legislature finds that surface water problems can be corrected and prevented through plans 

and programs for surface water improvement and management that are designed and 

implemented by the regional water management districts, with the participation and 

cooperation of the state’s agencies and local governments. 

(6) It is therefore the intent of the Legislature that each water management district design and 

implement plans and programs for the improvement and management of surface waters. 

(7) It is also the intent of the Legislature that statewide research be conducted to provide a better 

scientific understanding of the causes and effects of surface water pollution and of the 

destruction of natural systems in order to improve and manage surface waters and associated 

natural systems. 

Section 2. Surface water improvement and management plans and programs. 

(1) Each water management district, in cooperation with the Department of Environmental 

Regulation, the Game and Fresh Water Fish Commission, and the Department of Natural 

Resources, shall prepare a list, by March 1, 1988, which shall prioritize water bodies of regional 

or statewide significance within each water management district. The list shall be based on 

criteria adopted by rule of the Department of Environmental Regulation and shall assign 

priorities to the water bodies based their need for protection and restoration. Criteria developed 

by the Department of Environmental Regulation shall include, but need not be limited to, 

consideration of violations of water quality standards occurring in the water body, the amounts 

of nutrients entering the water body and the water body’s trophic state, the existence of or need 

for a continuous aquatic weed control program in the water body, the biological condition of the 

lake, reduced fish and wildlife values, and threats to agricultural and urban water supplies and 

recreational opportunities. The sum of $500,000 shall be available from the Surface Water 
Appendix A 

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Improvement and Management Trust Fund to the Department of Environmental Regulation for 

fiscal year 1987-1988 to be used cooperatively by the department and the water management 

districts to identify and prioritize water bodies within the district that are of regional and 

statewide significance and in need of restoration. In developing their respective priority lists, 

water management districts shall give consideration to the following priority areas: 

(a) The South Florida Water Management District shall give priority to the restoration needs of 

Lake Okeechobee, Biscayne Bay, and the Indian River Lagoon system and their tributaries. 

(b) The Southwest Florida Water Management District shall give priority to the restoration 

needs of Tampa Bay and its tributaries. 

(c) The St. Johns River Water Management District shall give priority to the restoration needs of 

Lake Apopka, the Lower St. Johns River, and the Indian River Lagoon system and their 

tributaries. 

(2) Once the priority lists are established, the water management districts, in cooperation with the 

Department of Environmental Regulation, the Game and Fresh Water Fish Commission, the 

Department of Natural Resources, and local governments, shall develop surface water 

improvement and management plans for the water bodies based on the priority lists approved 

by the Department of Environmental Regulation. Each plan shall include a schedule established 

by the water management district and agreed to by the Department of Environmental 

Regulation for restoring water bodies on the priority list. These plans shall also enumerate 

preventive measures which need to be taken to augment surface water improvement and 

management efforts. The Department of Environmental Regulation shall establish a uniform 

format for such plans. The plans shall be reviewed and, if necessary revised annually by the 

water management districts. These plans shall include, but not be limited to: 

(a) A description of the water body system, its historical and current uses, its hydrology, and a 

history of the conditions which have led to the need for restoration; 

(b) An identification of all governmental units that have jurisdiction over the water body and 

the land within a 1-mile perimeter of the water body, including local, regional, state, and 

federal units; 

(c) A description of adjacent land uses and those of important tributaries, point and nonpoint 

sources of pollution, and permitted discharge activities; 

(d) A list of the owners of point and nonpoint sources of water pollution that are discharged 

into each water body and tributary thereto and that adversely affect the public interest, 

including separate lists of those sources that are: 

1. Operating without a permit; 

2. Operating with a temporary operating permit; and 

3. Presently violating effluent limits or water quality standards. 

The plan shall also include a timetable for bringing all sources into compliance with state standards when 

not contrary to the public interest. This paragraph does not authorize any existing or future violation of 

any applicable statute or regulation and does not diminish the authority of the Department of 

Environmental Regulation; 
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(e) A description of strategies and potential strategies for restoring the water body to Class III 

or better; 

(f) A listing of studies that are being or have been prepared for the surface water body; 

(g) A description of the research and feasibility studies which will be performed to determine 

the particular strategy or strategies to restore the water body; 

(h) A description of the measures needed to manage and maintain the water body once it has 

been restored and to prevent future degradation; and 

(i) An estimate of the funding needed to carry out the restoration strategies. 

(3) Each water management district shall be responsible for planning, implementing, and 

coordinating restoration strategies for the priority water bodies within the district which have 

been approved by the Department of Environmental Regulation as water bodies of regional and 

statewide significance in need of restoration. The governing board of the appropriate water 

management district shall hold at least one public hearing and public workshops in the vicinity 

of the water body under consideration as may be necessary for obtaining public input prior to 

finalizing the surface water improvement and management plans for the water bodies on the 

priority list. The water management district shall then forward a copy of the plans to the 

Department of Environmental Regulation and to appropriate local governmental units. By 

September of 1988 and each September thereafter, the water management districts, in 

cooperation with the Department of Environmental Regulation, shall develop a funding 

proposal for the next fiscal year’s water restoration activities for priority water bodies which 

specifies the activities that need funding and the amounts of funding and. fully describes the 

specific restoration activities proposed. 

(4) The governing board of each water management district is encouraged to appoint advisory 

committees as necessary to assist in formulating and evaluating strategies for water body 

protection and restoration activities and to increase public awareness and intergovernmental 

cooperation. Such committees should include representatives of the Game and Fresh Water Fish 

Commission, the Department of Natural Resources, the Department of Agriculture and 

Consumer Services, appropriate local governments, federal agencies, existing advisory councils 

for the subject water body, and representatives of the public who use the water body. 

(5) The water management districts may contract with appropriate state, local, and regional 

agencies to perform various tasks associated with implementation of the surface water 

improvement and management plans. 

Section 3. Review of surface water improvement and management plans. 

(1) At least 30 days prior to any public hearing on its surface water improvement and management 

plan, a water management district shall transmit its proposed plan to the Department of 

Environmental Regulation, the Game and Fresh Water Fish Commission, the Department of 

Agriculture and Consumer Services, and the Department of Natural Resources and shall 

transmit a summary of the proposed plan to affected counties and municipalities. A copy of the 

proposed plan shall be provided to any affected county or municipality upon request. 
Appendix A 

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205 

(2) The Department of Environmental Regulation shall review each proposed surface water 

improvement and management plan for the purpose of determining: 

(a) Whether the costs described in the plan, as projected by the water management districts, are 

reasonable estimates of the actual costs of the programs in the plan; 

(b) The likelihood of the programs in the plan resulting in significant improvements in water 

quality in the priority surface waters designated in the plan; and 

(c) The combination of programs which can be funded based on available revenues within the 

Surface Water Improvement and management Trust Fund. If the department determines 

that a plan or program does not meet these requirements, that the projected costs are not 

reasonable estimates of the actual costs of the programs in the plan, or that a program in the 

plan is not likely to result in significant water improvements in the priority surface water, 

the department shall recommend modifications of or additions to the plan, or a program 

thereof, to the district at the district’s public hearing on the proposed plan. 

(3) The Game and Fresh Water Fish Commission shall review each proposed surface water 

improvement and management plan for the purpose of determining the effects of the plan on 

wild animal life and freshwater aquatic life and their habitats. If the commission determines that 

the plan, or a program thereof, has adverse effects on these resources, and that such adverse 

effects exceed the beneficial effects on these resources, the commission shall recommend 

modifications of or additions to the plan, or a program thereof, to the district at the district’s 

public hearing on the proposed plan. The commission shall also recommend to the district at the 

district’s public hearing on the proposed plan any modification or addition to the plan, or a 

program thereof, which would result in additional beneficial effects on wild animal life or 

freshwater aquatic life or their habitats. 

(4) The Department of Natural Resources shall review each proposed surface water improvement 

and management plan for the purpose of determining the effects of the plan on state-owned 

lands and on marine and estuarine aquatic life and their habitats. If the department determines 

that the plan, or a program thereof, has adverse effects on these resources, and that such 

adverse effects exceed the beneficial effects on these resources, the department shall recommend 

modifications of or additions to the plan, or a program thereof, to the district at the district’s 

public hearing on the proposed plan. The department shall also recommend modifications of or 

additions to the plan, or a program thereof, to the district at the district’s public hearing on the 

proposed plan. 

(5) The Department of Agriculture and Consumer Services shall review each proposed surface 

water improvement and management plan for the purpose of determining the effects of the 

plan on the agricultural resources of the area and the state. If the department determines that 

the plan, or a program thereof, has adverse effects on these resources, and that such adverse 

effects exceed the beneficial effects on these resources, the department shall recommend 

modifications of or additions to the plan, or a program thereof, to the district at the district’s 

public hearing on the proposed plan. The department shall also recommend modifications of or 

additions to the plan, or a program thereof, to the district at the district’s public hearing on the 

proposed plan. 
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(6) The water management districts, the Department of Environmental Regulation, the Department 

of Transportation, the Department of Natural Resources, and the Department of Health and 

Rehabilitative Services shall review their rules as they pertain to pollution of surface waters to 

determine where such rules could be strengthened to protect surface waters. The agencies shall 

also review their- enforcement programs for weaknesses in pursuing violations which result in 

surface water pollution. By March 1, 1988, the agencies shall report to the Governor, the Speaker 

of the House of Representatives, the President of the Senate, and the minority leaders of the 

House of Representatives and the Senate, and their findings and recommendations for 

remedies. 

Section 4. Implementation of surface water improvement and management plans and programs. 

(1) The funds in the Surface Water Improvement and Management Trust Fund shall be available to 

the water management districts for detailed planning for and implementation of surface water 

improvement and management plans. However, sections 1-6 of this act do not prohibit a water 

management district from requesting and receiving funds from the Surface Water Improvement 

and Management Trust Fund prior to March 1, 1988, for surface water improvement and 

management activities. 

(2) In developing implementing programs for their surface water improvement and management 

plans, the water management districts shall consider the following program recommendations 

for the use of funds for fiscal year 1987-1988 in the priority areas identified in Section 2 of this 

act: 

(a) The sum of $4,800,000 shall be available for the South Florida Water Management District 

for Lake Okeechobee. 

(b) The sum of $2,000,000 shall be available for the South Florida Water Management District 

for Biscayne Bay, of which up to $500000 is recommended to clean up the Miami River. The 

remainder of the funds available are recommended for retrofitting the 55 stormwater 

outfalls already identified by the Environmental Resources Management Department of 

Metro-Dade County as posing the greatest threat to the Biscayne Bay area or for other 

projects or activities that will contribute to the restoration of Biscayne Bay. 

(c) The sum of $1,500,000 shall be available for the Indian River Lagoon System, of which up to 

$178,000 is recommended for the Marine Resource Council. For the funds made available 

for this area and recommended to be used, 70 percent shall be available for programs of the 

St. Johns River Water Management District and 30 percent shall be available for programs 

of the South Florida Water Management District. The secretary of the Department of 

Environmental Regulation shall settle any dispute between the two districts relating to 

funding allocations. 

(d) The sum of $2,000,000 shall be available for the Southwest Florida Water Management 

District for Tampa Bay and its estuaries, of which up to $850,000 is recommended for a 

water quality assessment and scientific information compilation. 

(e) The sum of $2,200,000 shall be available for the St. Johns River Water Management District 

for Lake Apopka. 
Appendix A 

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207 

(f) The sum of $2,500,000 shall be available for the St. Johns River Water Management District 

for the Lower St. Johns River, of which up to $1,000,000 is recommended for stormwater 

cleanup based on Duval County’s providing equal matching funds. 

The amounts set forth in this subsection for the priority areas that are unencumbered at the end of fiscal 

year 1987-1988 shall remain in the Surface Water Improvement and Management Trust Fund and be 

available for the water bodies previously assigned. 

(3) Each water management district shall prepare detailed plans for and shall implement the 

programs in its surface water improvement and management plan upon the release of funds by 

the Department of Environmental Regulation. 

(4) Each water management district shall update annually, as necessary, its approved surface water 

improvement and management plan. If a district determines that modifications of or additions 

to its plan are necessary, such modifications or additions shall be subject to the review process 

established in section 3 of this act. 

Section 5. Surface Water Improvement and Management Trust Fund. 

(1) There is created, within the Department of Environmental Regulation, the Surface Water 

Improvement and Management Trust Fund to be used as a nonlapsing fund for the deposit of 

funds appropriated by the Legislature for the purposes of sections 1-6 of this act. The 

department shall administer all funds appropriated to or received for the Surface Water 

Improvement and Management Trust Fund. The moneys in the Surface Water Improvement 

and Management Trust Fund are continually appropriated for the purposes of sections 1-6 of 

this act. Expenditure of the moneys shall be limited to the costs of detailed planning for and 

implementation of programs prepared for priority surface waters. Moneys from the fund shall 

not be expended for planning for, or construction or expansion of, treatment facilities for 

domestic or industrial waste disposal. 

(2) The secretary of the Department of Environmental Regulation shall authorize the release of 

money from the Surface Water Improvement and Management Trust Fund within 30 days after 

receipt of a resolution adopted by the governing board of a water management district 

certifying that the money is needed for detailed planning for or implementation of programs 

approved pursuant to section 2 of this act. Beginning with the state fiscal year 1988-1989 and 

annually thereafter, a water management district may not receive more than 30 percent of the 

moneys in the Surface Water Improvement and Management Trust Fund in any fiscal year 

unless otherwise provided by law. 

(3) The amount of money that may be released to a water management district from the Surface 

Water Improvement and Management Trust Fund for approved programs, or continuations of 

approved programs, to improve and manage the surface waters described in sections 1-6 of this 

act is limited to not more than 80 percent of the amount of money necessary for the approved 

programs. The district shall provide at least 20 percent of the amount of money necessary for 

the programs. 

(4) Moneys in the trust fund, which are not needed to meet current obligations incurred under this 

section shall be transferred to the State Board of Administration, to the credit of the trust fund, 
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208 

to be invested in the manner provided by law. Interest received on such investments shall be 

credited to the trust fund. 

Section 6. Lake Okeechobee improvement and management. 

(1) LAKE OKEECHOBEE PROGRAM.—The South Florida Water Management District shall 

immediately design and implement a program to protect the water quality of Lake Okeechobee. 

Such program shall be based upon the recommendations of the Lake Okeechobee Technical 

Advisory Committee report entitled “Final Report: Lake Okeechobee Technical Committee” and 

dated August 1986, including the recommendations relating to the diversion of Taylor CreekNubbins Slough, but such program may include other projects. In addition, the program design 

shall be completed by December 1, 1988, and shall be designed to result, by July 1, 1992, in 

reductions of phosphorous loadings to the lake by the amount specified as excess in the South 

Florida Water Management District’s Technical Publication 81-2. 

(2) DIVERSIONS; LAKE OKEECHOBEE TECHNICAL ADVISORY COUNCIL.— 

(a) The Legislature finds that efforts to reduce nutrient levels in Lake Okeechobee have resulted 

in diversions of nutrient-laden waters to other environmentally sensitive areas, which 

diversions have resulted in adverse environmental effects. The Legislature also finds that 

both the agriculture industry and the environmental community are committed to 

protecting Lake Okeechobee and these environmentally sensitive areas from further harm 

and that this crisis must be addressed immediately. Therefore: 

1. The South Florida Water Management District shall not divert waters to the Indian Riverestuary, the Caloosahatchee River or its estuary, or the Everglades National Park, in such 

a way that the state water quality standards are violated, that the nutrients in such 

diverted waters adversely affect indigenous vegetation communities or wildlife, or that 

fresh waters diverted to the Caloosahatchee or Indian River estuaries adversely affect the 

estuarine vegetation or wildlife, unless the receiving waters will biologically benefit by 

the diversion. However, diversion is permitted when an emergency is declared by the 

water management district, if the secretary of the Department of Environmental 

Regulation concurs. 

2. The South Florida Water Management district may divert waters to other areas, including 

Lake Hicpochee, unless otherwise provided by law. However, the district shall monitor 

the effects of such diversions to determine the extent of adverse or positive 

environmental effects on indigenous vegetation and wildlife. The results of the 

monitoring shall be reported to the Lake Okeechobee Technical Advisory Council. If the 

monitoring of such diversions reveals continuing adverse environmental effects, the 

district shall make recommendations to the Legislature by July 1, 1988, on how to cease 

the diversions. 

(b) l. There is hereby created a Lake Okeechobee Technical Advisory Council. Council members 

shall be experts in the fields of botany, wildlife biology, aquatic biology, water quality 

chemistry, or hydrology and shall consist of: 

a. Three members appointed by the Governor; 
Appendix A 

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209 

b. Three members appointed by the Speaker of the House of Representatives; 

c. Three members appointed by the President of the Senate; 

d. One member from the Institute of Food and Agricultural Sciences, University of 

Florida, appointed by the President of the University of Florida; and 

e. One member from the College of Natural Sciences, University of South Florida, 

appointed by the President of the University of South Florida. 

Members shall be appointed not later than July 15, 1987. 

2. The purpose of the council shall be to investigate the adverse effects of past diversions of 

water and potential effects of future diversions on indigenous wildlife and vegetation 

and to report to the Legislature, no later than March 1, 1988, with findings and 

recommendations proposing permanent solutions to eliminate such adverse effects. 

3. The South Florida Water Management District shall provide staff and assistance to the 

council. The Department of Environmental Regulation, the Game and Fresh Water Fish 

Commission, and the district shall cooperate with the council. 

4. The council shall meet not less than once every 2 months at the call of the chairman, or at 

the call of four other members of the council. The council shall elect from its members a 

chairman and vice chairman and such other officers. as the council deems necessary. The 

council may establish other procedures for the conduct of its business. 

5. The members of the council are not entitled to compensation but are eligible for per diem 

and travel expenses pursuant to s. 112.061, Florida Statutes. 

Section 7. Section 5 of chapter 85-148, Laws of Florida, is amended to read: 

Section 5. The St. Johns River Water Management District governing board shall specify tasks which are 

to be undertaken by the district, the Department of Environmental Regulation, pertinent local 

governments, and the Game and Fresh Water Fish Commission in order to initiate the pilot project 

for Lake Apopka. The governing board shall: 

(1) Conduct extensive water sampling of the lake and its associated tributaries to determine the 

existing water quality and to determine the long term effects of nutrient loading from 

agricultural activities. 

(2) Evaluate the restoration of a portion of floodplain marsh between Lake Apopka and the 

Apopka-Beauclair Lock by allowing sheet-flow of waters prior to their entrance to the ApopkaBeauclair Canal. 

(3) Develop a nutrient budget for the lake to ensure that appropriate regulatory efforts are 

instituted with respect to nutrient loading. 

(4) Examine techniques which may be used to modify the existing physical and biological 

characteristics of the lake. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

210 

(5) Conduct a feasibility study to determine the effects of diking-off and restoring the littoral zone 

of the lake to enhance sportfish production. 

(6) Implement and evaluate a program to demonstrate the feasibility of utilizing water hyacinths to 

extract excessive nitrogen and phosphorous phosphorus from the sediment and water columns 

of the lake. 

(7) Implement and evaluate a program to demonstrate the feasibility of recreating a marsh along the 

lake shoreline using muck dredged from the lake bottom. 

(8) From funds appropriated by this act, expend up to $100,000 to contract for a feasibility study on 

the recycling of muck from Lake Apopka. 

(9) Conduct a study to determine the feasibility of using ichthyofauna reconstruction as a lake 

restoration method. 

These tasks and other related pilot studies may be conducted in water bodies other than Lake Apopka if 

the St. Johns River Water Management District determines it would be scientifically and technically 

acceptable and economically advantageous. The St. Johns River Water Management District shall assign a 

staff person to act as the executive director of the Lake Apopka Restoration Council and provide 

reasonable staff support for the provide the staff for the Lake Apopka Restoration Council while engaged 

in carrying out the provisions of this act. 

Section 8. Section 7 of chapter 85-148, Laws of Florida, is amended to read: 

Section 7. It is the intent of the Legislature that the St. Johns River Water Management District shall 

encourage competition among contractors for projects, through competitive bid, award contracts to 

implement the provisions of this act. Accordingly, the district shall be governed by its laws and 

policies for selecting contractors for scientific and technical research projects.

Section 9. The Department of Environmental Regulation shall conduct a study and make a report 

evaluating the current surface water classification system. The report shall include a review of the 

relationship of this classification system to the classification system used for shellfish harvesting 

waters and specifically consider whether the classifications applied to artificially created or 

significantly altered water bodies are appropriate; provided, however, that consideration shall also 

be given to the impacts of artificially created or significantly altered water bodies on other water 

bodies that have fish and wildlife values. However, artificially created or significantly altered water 

bodies to be considered for reclassification in the report shall not include those water bodies that 

are: 

(1) Determined to have viable or high potential for viable fish and wildlife populations; 

(2) Located in high groundwater recharge areas; or 

(3) Determined to have high recreational usage. 

Prior to initiating the study, the department shall publish notice and invite participation from local 

governments, affected interest groups, and other state and federal agencies. The report shall be submitted 
Appendix A 

St. Johns River Water Management District

211 

to the Governor, the Speaker of the House of Representatives, and the President of the Senate no later 

than March 1, 1989. In addition, the department shall notify the Governor, the Speaker of the House of 

Representatives, and the President of the Senate by January 15, 1988, of the data needed to adopt and 

implement rules establishing limits for discharges of nitrogen and phosphorous into the waters of the 

state and the costs of obtaining the data. 

Section 10. Subsection (3) of section 373.503, Florida Statutes, is amended to read: 

373.503 Manner of taxation. 

(3)(a) The districts may levy ad valorem taxes on property within the district solely for the purposes 

of this chapter and of chapter 25270, Laws of Florida, 1949, as amended, and chapter 61-691, 

Laws of Florida, as amended. The authority to levy ad valorem taxes as provided in this act 

shall commence with the year 1977. However, the taxes levied for 1977 by the governing boards 

pursuant to this section shall be prorated to ensure that no such taxes will be levied for the first 

4 days of the tax year, which days will fall prior to the effective date of the amendment to s. 9(b), 

Art. VII of the Constitution of the State of Florida, which was approved March 9, 1976. When 

appropriate, taxes levied by each governing board may be separated by the governing board 

into a millage necessary for the purposes of the district and a millage necessary for financing 

basin functions specified in s. 373.0695. Beginning with the taxing year 1977, and not 

withstanding the provisions of any other general or special law to the contrary, the maximum 

total millage rate for district and basin purposes shall be: 

1. Northwest Florida Water Management District: 0.05 mill. 

2. Suwannee River Water Management District: 0.75 mill. 

3. St. Johns River Water Management District: 0.6 0.375 mill, plus an additional .225 mill 

which may be used only for land acquisition and capital projects associated with such 

acquisition. 

4. Southwest Florida Water Management District: 1.0 mill. 

5. South Florida Water Management District: 0.80 mill. 

(b) The maximum millage assessed for district purposes shall not exceed 25 percent of the total 

authorized millage when there are one or more basins in a district, and the maximum 

millage assessed for basin purposes shall not exceed 75 percent of the total authorized 

millaqe, except that: 

1. The apportionment in the South Florida Water Management District St. Johns River Water 

Management District shall be a maximum of 40 15 percent for district purposes and a 

maximum of 60 85 percent for basin purposes, respectively. 

2. Within the Southwest Florida Water Management District, the maximum millage assessed for 

district purposes shall not exceed 40 percent of the total authorized millage when there are 

one or-more basins in the district, and the maximum millage assessed for basin purposes 

shall not exceed 60 70 percent of the total authorized millage. 

Continued... 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

212 

Section 23. Beginning in fiscal year 1988-1989 and annually thereafter at least $35 million shall 

be available from the State Infrastructure Trust Fund for the purposes provided in s. 

161.091(l), Florida Statutes. 

Section 24. This act shall take effect July 1, 1987, or upon becoming a law, whichever occurs 

later. 

Approved by the Governor June 29, 1987. 

Filed in Office Secretary of State June 29, 1987. 
Appendix A 

St. Johns River Water Management District

213 

CHAPTER 96-207 

Committee Substitute for Senate Bill No. 2954 

An act relating to Lake Apopka restoration; creating s. 373.461, F.S.; providing findings and 

legislative intent; providing that it is the intent of the Legislature to enhance and accelerate 

the restoration process begun by previous acts of the Legislature relating to the restoration 

of the Lake Apopka basin; providing that acquisition of agricultural lands impacting Lake 

Apopka would serve the public interest; providing intent regarding the development of a 

process to limit the discharge of phosphorus into the lake and the cost-sharing of such a 

process; providing definitions; providing for the construction of stormwater-management 

facilities; providing for cost-sharing by the state, the St. Johns River Water Management 

District, and the Zellwood Drainage and Water Control District; providing for the 

responsibilities of the St. Johns River Water Management District and the Zellwood 

Drainage and Water Control District; granting the St. Johns River Water Management 

District the power of eminent domain over certain specified lands; providing for the 

purchase of certain lands under certain conditions; providing that certain existing consent 

or settlement agreements are not affected and will remain in effect; providing that existing 

water-quality standards are not altered; providing an appropriation; providing an effective 

date. 

Be It Enacted by the Legislature of the State of Florida: 

Section 1. Section 373.461, Florida Statutes, is created to read: 

373.461 Lake Apopka Improvement and Management. 

(1) FINDINGS AND INTENT.— 

(a) The Legislature has expressed its intent that economically and technically feasible methods be 

developed to restore the Lake Apopka basin through the Lake Apopka Restoration Act and 

the Surface Water Improvement and Management Act. It is the Legislature’s intent to 

enhance and accelerate the restoration process begun by those previous acts of the 

Legislature. 

(b) Technical studies have determined that substantial reductions in or elimination of phosphorus 

in farm discharges to Lake Apopka will be necessary in order to improve water quality and 

restore the lake to Class III standards. 

(c) Acquisition of the lands in agricultural production which discharge phosphorus to Lake 

Apopka, and their related facilities, would serve the public interest by eliminating the 

impacts of introduction of phosphorus from these sources into the lake. It is the Legislature’s 

intent that a fair and equitable program of acquisition of the lands necessary to achieve the 

purposes of this section be implemented. 

(d) The Legislature finds that time is of the essence and that a complete purchase of properties 

described in this section should be accomplished in an accelerated and economical manner. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

214 

(e) If funds cannot be identified for acquisition of these agricultural lands, it is the Legislature’s 

intent to provide a process for development of phosphorus-discharge limitations that will 

bring such discharges into compliance with state water-quality standards and to provide for 

interim phosphorus abatement measures designed to further reduce phosphorus discharges 

from the Zellwood Drainage and Water Control District, which is the largest agricultural 

entity within the Lake Apopka Basin. The Legislature finds that it is in the public interest to 

jointly share in the cost of implementing such interim phosphorus reduction measures with 

Zellwood. 

(f) A. Duda and Sons, Inc., has implemented phosphorus treatment and has worked 

cooperatively with the district to meet applicable water-quality standards. An existing 

settlement agreement outlines treatment measures that should satisfy all discharge 

limitations and criteria. 

(2) DEFINITIONS.-As used in this section: 

(a) “District” means the St. Johns River Water Management District. 

(b) “Phosphorus criterion” means a numeric interpretation for phosphorus of the Class III 

narrative nutrient criterion. 

(c) “Stormwater management system” has the meaning set forth in s. 373.403(10). 

(d) “Zellwood” means the Zellwood Drainage and Water Control District as it is described in 

chapter 20715, Laws of Florida. 

(3) PHOSPHORUS CRITERION AND DISCHARGE LIMITATIONS FOR LAKE APOPKA. 

(a) The district shall, no later than September 30, 1996, file a notice of rulemaking in the Florida 

Administrative Weekly to establish a phosphorus criterion for Lake Apopka. 

(b) In the event the district does not adopt a rule establishing a phosphorus criterion for Lake 

Apopka by January 1997, the phosphorus criterion for the lake shall be 55 parts per billion 

(ppb). 

(c) The district shall adopt by rule discharge limitations for all permits issued by the district for 

discharges into Lake Apopka, the Lake Level Canal, and the McDonald Canal. 

(4) CONSTRUCTION OF STORMWATER-MANAGEMENT SYSTEMS. 

(a) It is the intent of the Legislature that in the event no funding mechanisms to purchase all the 

lands within Zellwood are in place by July 1, 1997, construction of stormwater-management 

facilities to store, treat, and recycle Zellwood’s agricultural stormwater runoff will be 

necessary during the interim period while discharge limitations are being established for 

Lake Apopka. The Legislature finds that it is in the public interest for state, regional, and 

local revenue sources to be used along with Zellwood’s revenue sources to finance the costs 

of acquiring land and constructing such facilities. One-third of the cost of the facilities shall 

be contributed by Zellwood, one-third by the state, and one-third by the district. 
Appendix A 

St. Johns River Water Management District

215 

(b) Consistent with the funding formula outlined in paragraph (a), the state will provide up to $2 

million, with the same amount being committed by both Zellwood and the district, for a total 

of $6 million. These funds shall be used for the purpose of acquiring the necessary land for 

and constructing a stormwater-management facility, not to exceed 600 acres in total size, for 

Zellwood’s farm runoff, together with the necessary pumps and other infrastructure 

associated with such facilities, provided that Zellwood’s contribution shall be used for project 

purposes other than acquiring land. 

(c) The district shall be responsible for design of the facilities and for acquiring any necessary 

interest in land for the facilities. Zellwood will be responsible for construction of the facilities 

in accordance with the district’s design. The district will administer the funds provided for 

under this section. No later than September 30, 1997, the district and Zellwood will develop 

an agreement regarding dispersal of funds for construction of the facilities which shall take 

into account the financing mechanisms available to the parties. Zellwood shall not be 

required to assess more than $25 per acre per year in financing its share of the stormwater 

management facility. However, it must provide its one-third share of the funding within the 

timeframes outlined for construction of the stormwater construction facility outlined in this 

section. 

(d) Construction of the stormwater retention and treatment facilities provided for in this section 

shall begin within 90 days after acquisition of interests in land necessary for the facilities and 

completed, within 1 year thereafter. After completion of the facilities, Zellwood shall be 

responsible for operation and maintenance so long as the facilities are used by Zellwood. 

(e) The district may, as appropriate, alter or modify the design of the facility to reduce the cost of 

the acquisition and construction of the facility if lands presently in production within 

Zellwood are acquired pursuant to subsection (5) before construction of the facility. The 

district shall have the flexibility to adjust these dates due to any unforseen circumstances 

such as, and not limited to, acts of God, delays due to litigation by outside parties, or 

unnecessary or unforseen permitting or construction delays. 

(f) The district and Zellwood hall give preferential consideration to the hiring of agricultural 

workers displaced as a result of the Lake Apopka Restoration Act, consistent with their 

qualifications and abilities, for the construction and operation of the stormwater facility. 

(5) PURCHASE OF AGRICULTURAL LANDS. 

(a) The Legislature finds that it is in the public interest of the state to acquire lands in agricultural 

production, along with their related facilities, which contribute, directly or indirectly, to 

phosphorus discharges to Lake Apopka, for the purpose of improving water quality in Lake 

Apopka. These lands consist of those farming entities on Lake Apopka having consent and 

settlement agreements with the district and those sand land farms discharging indirectly to 

Lake Apopka through Lake Level Canal, Apopka-Beauclair Canal, or McDonald Canal. The 

district is granted the power of eminent domain on those properties. 

(b) In determining the fair market value of lands to be purchased from willing sellers, all 

appraisals of such lands may consider income from the use of the property for farming and, 

for this purpose, such income shall be deemed. attributable to the real estate. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

216 

(c) The district shall explore the availability of funding from all sources, including any federal, 

state, regional, and local land acquisition funding programs, to purchase the agricultural 

lands described in paragraph (a). It is the Legislature’s intent that, if such funding sources 

can be identified, acquisition of the lands described in paragraph (a) may be undertaken by 

the district to purchase these properties from willing sellers. 

(d) In connection with successful acquisition of any of the lands described in this section which 

are not needed for stormwater-management facilities, the district shall give the seller the 

option to lease the land for a period not to exceed 5 years, at a fair market lease value for 

similar agricultural lands. Proceeds derived from such leases shall be used to offset the cost 

of acquiring the land. 

(e) If the lands within Zellwood are purchased in accordance with this section prior to expiration 

of the consent agreement between Zellwood and the district, Zellwood shall be reimbursed 

for any costs described in subsection (4). 

(6) EXISTING CONSENT OR SETTLEMENT AGREEMENTS PRESERVED.-Except to the extent 

specifically modified in this section, the district’s existing consent or settlement agreements with 

A. Duda and Sons, Inc., and Zellwood, including requirements regarding compliance with any 

discharge limitations established for Lake Apopka, shall remain in effect. 

(7) APPLICABILITY OF LAWS AND WATER-QUALITY STANDARDS; AUTHORITY OF DISTRICT 

AND DEPARTMENT. 

(a) Except as otherwise provided in this section, nothing in this section shall be construed: 

1. As altering any applicable state water-quality standards, laws, or district or department 

rules; or 

2. To restrict the authority otherwise granted the department and the district pursuant to this 

chapter or chapter 403. The provisions of this section shall be deemed supplemental to the 

authority granted pursuant to this chapter and chapter 403. 

Section 2. As provided in the General Appropriations Act for fiscal year 1996-1997, only, there is 

appropriated from funds deposited in the Conservation and Recreation Lands Trust Fund the sum 

of $12 million to the St. Johns River Water Management District, to be used for the purpose of 

purchasing lands described in section 373.461(6)(a), Florida Statutes. In addition, the St. Johns River 

Water Management District is directed to use $8 million from its share of funds from the Water 

Management Lands Trust Fund or from funds derived from revenue bonds using Water 

Management Lands Trust Fund revenues as the revenue source for the purpose of purchasing lands 

described in section 373.461(5)(a), Florida Statutes. 

Section 3. This act shall take effect July 1, 1996. 

Approved by the Governor May 24, 1996. 

Filed in Office Secretary of State May 24, 1996. 
Appendix A 

St. Johns River Water Management District

217 

CHAPTER 97-81 

Committee Substitute for Senate Bill No. 1486 

An act relating to community redevelopment; authorizing the Office of Tourism, Trade, and 

Economic Development to amend the boundaries of certain enterprise zones; providing 

restrictions; providing for repeal; amending s. 373.461, F.S., relating to Lake Apopka 

improvement and management; providing legislative intent that interim phosphorus 

abatement measures be provided and stormwater management facilities be constructed 

unless specified time requirements for land purchase are met; revising provisions relating to 

commencement of construction of stormwater facilities; providing a maximum purchase 

price for certain agricultural lands; providing for sale of certain tangible personal property 

and for use of the proceeds of such sale; authorizing the Office of Tourism, Trade, and 

Economic Development to expend such funds; providing for use of an appropriation made 

by ch. 96-207, Laws of Florida; creating s. 290.0067, F.S.; authorizing Orange County and 

Apopka to apply for designation of an enterprise zone in areas suffering adverse impacts 

due to governmental acquisition of Lake Apopka farmlands; authorizing the Office of 

Tourism, Trade, and Economic Development to designate such zone and providing a 

termination date; authorizing the Office of Tourism, Trade, and Economic Development to 

amend the boundaries of certain areas; providing for severability; providing an effective 

date. 

Be It Enacted by the Legislature of the State of Florida: 

Section 1. Notwithstanding any other provision of law, prior to June 30, 1998, the Office of Tourism, 

Trade, and Economic Development may amend the boundaries of an area designated as an 

enterprise zone in a community having a Population of 7,500 persons or more but less than 20,000, 

so long as the area does not increase the overall size of the zone. The amendment must also be 

consistent with the limitations imposed by section 290.0055, Florida Statutes, upon establishment of 

the enterprise zone. 

Section 2. (1) The Office of Tourism, Trade, and Economic development may, no later than June 30, 1998, 

modify the boundaries of any enterprise zone that is located within an inland county having a 

population greater than 500,000, to allow for the expansion of one noncontiguous area, as long as 

the area added does not exceed 5 square miles and is consistent with the categories, criteria, and 

limitations imposed by this section and section 290.0055, Florida Statutes, upon the establishment of 

such an enterprise zone. 

(2) This section is repealed July 1, 1998.

Section 3. Paragraph (e) of subsection (1), paragraphs (a) and (d) of subsection (4), and paragraphs (c) and 

(e) of subsection (5) of section 373.461, Florida Statutes, 1996 Supplement, are amended, and 

paragraphs (f) and (g) are added to subsection (5) of said section, to read: 

373.461 Lake Apopka improvement and management.- 

(1) FINDINGS AND INTENT. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

218 

(e) If funds cannot be identified for acquisition of these agricultural lands, It is the Legislature’s 

intent to provide a process for development of phosphorus discharge limitations that will 

bring such discharges into compliance with state water quality standards and to provide for 

interim phosphorus abatement measures designed to further reduce phosphorus discharges 

from the Zellwood Drainage and Water Control District, which is the largest agricultural 

entity within the Lake Apopka Basin, unless both of the timeframes specified in paragraph 

(4)(a) regarding purchase agreements and completion of purchases are met. The Legislature 

finds that it is in the public interest to jointly share in the cost of implementing such interim 

phosphorus reduction measures with Zellwood. 

(4) CONSTRUCTION OF STORMWATER MANAGEMENT SYSTEMS. 

(a) It is the intent of the Legislature that in the event no funding mechanisms to purchase all the 

lands within Zellwood are in place by July 1, 1997, construction of stormwater management 

facilities to store, treat, and recycle Zellwood’s agricultural stormwater runoff will be 

necessary during the interim period while discharge limitations are being established for 

Lake Apopka, unless both of the following conditions are met: 

1. Agreements to purchase all the lands within Zellwood are executed by September 30, 

1997, or a later execution deadline established by the United States for such agreements 

before reallocation of Commodity Credit Corporation funds made available to acquire 

wetland reserve program conservation easements within the Lake Apopka Partnership 

Project area; and 

2. All such purchases are completed pursuant to the terms of such agreements. 

The Legislature finds that it is in the public interest for state, regional, and local revenue sources to be 

used along with Zellwood’s revenue sources to finance the costs of acquiring land and constructing such 

facilities. One third of the cost of the facilities shall be contributed by Zellwood, one-third by the state, 

and one-third by the district. 

(d) Construction of the stormwater retention and treatment facilities provided for in this section 

shall begin within 90 days after acquisition of interests in land necessary for the facilities 

and the district’s delivery of the design of the facilities to Zellwood, and shall be completed 

within 1 year thereafter. After completion of the facilities, Zellwood shall be responsible for 

operation and maintenance so long as the facilities are used by Zellwood. 

(5) PURCHASE OF AGRICULTURAL LANDS.- 

(c) The district shall explore the availability of funding from all sources, including any federal, 

state, regional, and local land acquisition funding programs, to purchase the agricultural 

lands described in paragraph (a). It is the Legislature’s intent that, if such funding sources 

can be identified, acquisition of the lands described in paragraph (a) may be undertaken by 

the district to purchase these properties from willing sellers. However, the purchase price 

paid for acquisition of such lands that were in active cultivation during 1996 shall not 

exceed the highest appraisal obtained by the district for these lands from a state-certified 

general appraiser following the Uniform Standards of Professional Appraisal Practice. This 

maximum purchase price limitation shall not include, nor be applicable to, that portion of 
Appendix A 

St. Johns River Water Management District

219 

the purchase price attributable to consideration of income described in Paragraph (b), or 

that portion attributable to related facilities, or closing costs. 

(e) If all the lands within Zellwood are purchased in accordance with this section prior to 

expiration of the consent agreement between Zellwood and the district, Zellwood shall be 

reimbursed for any costs described in subsection (4). 

(f) 1. Tangible personal property acquired by the district as part of related facilities pursuant to 

this section, and classified as surplus by the district, shall be sold by the Department of 

Management Services. The Department of Management Services shall deposit the proceeds 

of such sale in the Economic Development Trust Fund in the Executive Office of the 

Governor. The proceeds shall be used for the purpose of providing economic and 

infrastructure development in portions of northwestern Orange County and east central 

Lake County which will be adversely affected economically due to the acquisition of lands 

pursuant to this subsection. 

2. The Office of Tourism, Trade, and Economic Development shall, upon presentation of the 

appropriate documentation justifying expenditure of the funds deposited pursuant to 

this paragraph, pay any obligation for which it has sufficient funds from the proceeds of 

the sale of tangible personal property and which meets the limitations specified in 

paragraph (h). The authority of the Office of Tourism, Trade, and Economic 

Development to expend such funds shall expire 5 years from the effective date of this 

paragraph. Such expenditures may occur without future appropriation from the 

Legislature. 

3. Funds deposited under this paragraph may not be used for any purpose other than those 

enumerated in paragraph (h). 

(g)1. The proceeds of sale of tangible personal property authorized by Paragraph (f) shall be 

distributed as follows: 60 percent to Orange County; 25 percent to the City of Apopka: and 

15 percent to Lake County. 

2. Such proceeds shall be used to implement the redevelopment plans adopted by the 

Orange County Board of County Commissioners, Apopka City Commission, and Lake 

County Board of County Commissioners. 

3. Of the total proceeds, the Orange County Board of County Commissioners, Apopka City 

Commission, and Lake County Board of County Commissioners, may not expend more 

than: 

a. Twenty percent for labor force training related to the redevelopment plan 

b. Thirty-three percent for financial or economic incentives for business location or 

expansion in the redevelopment area, and 

c. Four percent for administration, planning, and marketing the redevelopment plan. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

220 

4. The Orange County Board of County Commissioners, Apopka City Commission, and Lake 

County Board of County Commissioners must spend those revenues not expended under 

subparagraph 3. for infrastructure needs necessary for the redevelopment plan. 

Section 4. The $20 million appropriation in fiscal year 1996-1997 pursuant to chapter 96-207, Laws of 

Florida, shall be used for the purpose of purchasing lands described in section 373.461(5)(a), Florida 

Statutes, and their related facilities. 

Section 5. Section 290.0067, Florida Statutes, is created to read: 

290.0067 Enterprise zone designation for communities impacted by Lake Apopka land acquisition.-

Orange County and the municipality of Apopka may Jointly apply to the Office of Tourism, Trade, 

and Economic Development for designation of one enterprise zone encompassing areas suffering 

adverse economic impacts due to governmental acquisition of Lake Apopka farmlands pursuant to 

s. 373.461. The application must be submitted by December 31, 1998, and must comply with the 

requirements of s. 290.0055, excepts. 290.0055(3). Notwithstanding the provisions of s. 290.0065 

limiting the total number of enterprise zones designated and the number of enterprise zones within 

a population category, the Office of Tourism, Trade, and Economic Development may designate one 

enterprise zone under this section The Office of Tourism, Trade, and Economic Development shall 

establish the initial effective date of the enterprise zone designated pursuant to this section based 

upon when unemployment will occur due to the cessation of farming on lands acquired pursuant to 

s. 373.461. The zone shall terminate 5 years following the established effective date. 

Section 6. Notwithstanding any other provisions of law, the Office of Tourism, Trade, and Economic 

Development may mend the boundaries of an area designated as an enterprise zone in a community 

having a population of 235,000 persons but less than 245,000, so long as the area does not increase 

the overall size of the zone by greater than 25 acres and the increased area is contiguous to the 

existing enterprise zone. The amendment must also be consistent with the limitations imposed by 

section 290.0055, Florida Statutes, upon establishment of the enterprise zone. 

Section 7. If any provision of this act or the application thereof to any person or circumstance is held 

invalid, the invalidity shall not affect other provisions or applications of the act which can be given 

effect without the invalid provision or application, and to this end the provisions of this act are 

declared severable. 

Section 8. This act shall take effect upon becoming a law.

Approved by the Governor May 23, 1997. 

Filed in Office Secretary of State May 23, 1997. 
Appendix A 

St. Johns River Water Management District

221 

SJR WATER 

MANAGEMENT 

DISTRICT 

July 30, 1996 

Ms. Liz Cloud, Chief F.O.R. 96-1679 

Bureau of Administrative Code 

The Elliott Building 

Tallahassee, Florida 32399-0250 

Dear Liz: 

Pursuant to 120.54(11)(b), F.S., please find enclosed for filing with the Department of State, an 

original and two copies of the following documents regarding revisions to chapter 40C-4, F.A.C, 

and Applicant’s Handbook: Management and Storage of Surface Waters. 

1. The certification of the above-referenced rule chapter, with text of the rule section and 

history notes attached. 

3. Summary of the rule, summary of the hearing held on the rule, statement of the facts and 

circumstances justifying the rule. 

We appreciate your assistance in this matter. If you have any questions, please do not hesitate to 

contact us. 

Sincerely, 

NORMA K. MESSER, Rules Coordinator 

Office of General Counsel 

/nkm 

Enclosures 

cc: Thomas M. Swihart, DEP 

 Bonnie Fowler, RegFiles
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

222 

CERTIFICATION OF 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

ADMINISTRATIVE RULES 

FILED WITH THE DEPARTMENT OF STATE 

I do hereby certify: 

[X] (1) The time limitations prescribed by paragraph 120.54(11)(a), F.S., have been 

complied with; and 

[X] (2) There is no administrative determination under subsection 120-54(4), F.S., 

pending on any rule covered by this certification; and 

[X] (3) All rules covered by this certification are filed within the prescribed time 

limitations of paragraph 120.54(11)(b), F.S. They are filed not less than 28 days 

after notice required by subsection 120.54(l), F.S., and; 

[X] (a) Are filed not more than 90 days after the notice; or 

[ ] (b) Are filed not more than 90 days after the notice, not including days an 

administrative determination was pending; or 

[ ] (c) Are filed within 21 days after the adjournment of the final public hearing on the 

rule, or 

[ ] (d) Are filed within 21 days after the date of receipt of all material authorized to be 

submitted at the hearing, or 

[ ] (e) Are filed within 21 days after the date the transcript was received by this agency. 

 Attached are the original and two copies of each rule covered by this certification. The 

rules are hereby adopted by the undersigned agency by and upon their filing with the 

Department of State. 

 Specific Law Being 

Rule No. Rule-Making Implemented or 

 Authority Made Specific 

40C-4. 091 120.54(8), 373.044, 373.046(4), 120.54(8), 373.O46, 373.413, 

373.113, 373.171, 373.415, 373.4135, 373.415, 373:416, 

373.421(2), 373.461(3) FS 373.421(2)-(6), 373.426, 373.461(3) FS 

Under the provision of paragraph 120.54(12)(a), F.S., the rules take effect 20 days from the date 

filed with the Department of date as set out below. 

Effective: _____________________ 

(month) (day) (year) 

WILLIAM M. SEGAL 

SJRWMD Governing Board Chairman

Title 

TWO 

Number of Pages Certified 
Appendix A 

St. Johns River Water Management District

223 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

ENVIRONMENTAL RESOURCE PERMITS: 

SURFACE WATER MANAGEMENT SYSTEMS 

RULE CHAPTER TITLE: RULE CHAPTER NO.: 

Environmental Resource Permits: Surface Water 

Management Systems 40C-4, F.A.C. 

RULE TITLE: RULE NO.: 

Publications Incorporated by Reference 40C-4.091, F.A.C. 

40C-4.091 Publications Incorporated by Reference: 

(1) The Governing Board hereby adopts by reference: 

(a) Part I “Policy and Procedures,” Part II “Criteria for Evaluation,” subsections 18.0, 

18.1, 18.2, and 18.3 of Part III and Appendix K “Legal Description Upper St. Johns River 

Hydrologic Basin,” “Legal Description Ocklawaha River Hydrologic Basin”, “Legal 

Description of the Wekiva River Hydrologic Basin,” “Legal Description of the 

Econlockhatchee River Hydrologic Basin,” “Legal Description of the Sensitive Karst 

Areas Basin. Alachua County,” and “Legal Description of the Sensitive Karst Areas 

Basin, Marion County,” and “Legal Description of the Lake Apopka Drainage Basin” of 

the document entitled “Applicant’s Handbook: Management and Storage of Surface 

Waters,” effective ___________ 10-3-95. 

 (b) No change 

 (2) No change 

Specific Authority 120-54(8), 373.044, 373.046(4), 373.113, 373.171, 373.415, 

373.421(2),373.461(3) FS. Law Implemented 120.54(8), 373.046, 373.413, 373.4135, 373.415, 

373.416, 373.421(2)-(6), 373.426, 373.461(3) FS. History—New 12-7-83, Amended 10-14-

84, Formerly 40C- 4.09 1, Amended 5-17-87, Formerly 40C-4.009 1, Amended 8-20-87, 

10-1-87, 10-11-87, 11-26-87, 8-30-88, 1-1-89, 8-1-89, 10-19-89, 4-3-91, 8-11-91, 9-25-91, 11-

12-91, 3-1-92, 7-14-92, 9-8-92, 9-16-92, 11-12-92, 11-30-92, 1-6-93, 1-23-94, 2-27-94, 11-22-

94, 10-3-95,_____. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

224 

CERTIFICATION OF 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

PUBLICATIONS INCORPORATED BY REFERENCE 

FILED WITH THE 

DEPARTMENT OF STATE 

I do hereby certify that the attached are correct and complete copies of amendments 

made to Part II and Appendix K of the document entitled “Applicant’s Handbook: 

Management and Storage of Service Waters,” incorporated by reference in section 40C4.091, F.A.C., effective ______________. 

(Date) 

WILLIAM M. SEGAL 

SJRWMD Governing Board Chair

 Title 

 SEVEN 

Number of Pages Certified 
Appendix A 

St. Johns River Water Management District

225 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

APPLICANT’S HANDBOOK: 

MANAGEMENT AND STORAGE OF SURFACE WATERS 

11.0 Basin Criteria 

Chapter 40C-41, F.A.C., and this section establishes additional criteria which are to be used in 

reviewing applications for permits in certain hydrologic basins. These basins are: 

(a) through (e) No change 

(f) Lake Apopka Hydrologic Basin

See Figure 11.0-1 for a description of the areas contains within the St. Johns River Hydrologic 

Basin, the Ocklawaha River Hydrologic Basin, the Wekiva River Hydrologic Basin, and the 

Econlockhatchee Hydrologic Basin. See Figures 11.0-2, 11.0-3, and 11.0-4 for a description of the 

areas contained within the Sensitive Karst Areas Basin. See Figure 11.0-5 for a description of the 

areas contained with the Lake Apopka Hydrologic Basin. A description of the Hydrologic Basin 

boundaries is available Appendix K. 

11. 1 through 11.5 No change 

11.6 Lake Apopka Drainage Basin

Pursuant to section 373.461(3)(a), F.S., the phosphorus criterion for Lake Apopka is 55 parts per 

billion. This phosphorus criterion shall be used to establish phosphorus discharge limitations 

for all permits within the Lake Apopka Drainage Basin authorizing discharges, directly or 

indirectly, into Lake Apopka, the Lake Level Canal, and the McDonald Canal.

APPENDIX K 

LEGAL DESCRIPTION OF THE LAKE APOPKA DRAINAGE BASIN

Begin at the Northeast corner of Section 29, Township 22 South, Range 28 East; thence South 

along the Section lines to the Southeast corner of the Northeast quarter of Section 32 Township 

22 South, Range 28 East, thence west along the quarter section line to the Southeast corner of the 

Northwest quarter of Section 31, Township 22 South, Range 28 East; thence South along, the 

quarter section line to the Southeast corner of the Southwest quarter of Section 31, Township 22 

South, Range 28 East; thence West along the Section lines to the Southwest corner of the 

Southeast quarter of Section 36, Township 22 South, Range 27 East; thence South along the 

quarter section line to the Southeast corner of the Southwest quarter of Section 1, Township 23 

South, Range 27 East; thence West along the Section line to the Southeast corner of Section 2, 

Township 23 South, Range 27 East; thence South along the Section lines to the Southeast corner 

of the Northeast quarter of Section 11 Township 23 South, Range 27 East; thence west along the 

quarter section line to the Southeast corner of the Northwest quarter of Section 11, Township 23 

South, Range 27 East; thence south along the quarter section line to the Southeast corner of the 

Southwest quarter of Section 11. Township 23 South, Range 27 East: thence West along the 

Section lines to the Southeast corner of the Southwest quarter of Section 7, Township 23 South, 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

226 

Range 27 East; thence South along the quarter section line to the Southeast corner of the 

Northwest quarter of Section 18, Township 23 South, Range 27 East: thence West along the 

quarter section line to the Southwest corner of the Northwest quarter of Section 18, Township 

23 South, Range 27 East: thence North along the Section line to the Southwest corner of Section 

7, Township 23 South, Range 27 East; thence West along the Section line to the Southwest corner 

of the Southeast quarter of Section 12, Township 23 South, Range 26 East; thence North along 

the quarter section line to the Southeast corner of the Southwest quarter of Section 1, Township 

23 South, Range 26 East; thence west. along the Section lines to the Southwest corner of the 

Southeast quarter of Section 6, Township 23 South, Range 26 East; thence North alone the 

quarter section line to the Northwest corner of the Northeast quarter of Section 6. Township 23 

South, Range 26 East; thence East along, the Section line to the Southwest corner of Section 32, 

Township 22 South, Range 26 East; thence North along the Section line to the Northwest corner 

of Section 32, Township 22 South, Range 26 East; thence East along the Section line to the 

Southwest corner of Section 28, Township 22 South, Range 26 East; thence North along the 

Section line to the Southwest corner of Section 4, Township 22 South, Range 26 East: thence 

West along the Section line to the Southwest corner of Section 5, Township 22 South, Range 26 

East; thence North along the Section lines to the Northwest corner of Section 32, Township 21 

South, Range 26 East; thence East along the Section line to the Northeast corner of the 

Northwest quarter of. Section 32, Township 21 South, Range 26 East; thence North along the 

quarter section lines to the Northwest corner of the Northeast quarter of Section 20. Township 

21 South, Range 26 East; thence East along the Section line to the Southwest corner of Section 16, 

Township 21 South, Range 26 East; thence North along the Section line to the Northwest comer 

of Section 16. Township 21 South, Range 26 East: thence East along the Section line to the 

Southwest corner of the Southeast quarter of Section 9 Township 21 South, Range 26 East; 

thence North along the quarter section line to the Northwest corner of the Southeast quarter of 

Section 4, Township 21 South. Range 26 East; thence West along the quarter section line to the 

Southwest corner of the Northwest quarter of Section 4, Township 21 South Range 26 East, 

thence North along the Section lines to the Northwest corner of Section 28, Township 20 South, 

Range 20 East, thence East along the Section lines to the Southwest corner of the Southeast 

quarter of Section 24, Township 20 South, Range 26 East; thence North along the quarter section 

line to the Northwest corner of the Southeast quarter of Section 24, Township 20 South, Range 

26 East; thence East along the quarter section line to the Northeast corner of the Southeast 

quarter of Section 24, Township 20 South, Range 26 East; thence North along the Section line to 

the Northwest corner of Section 19. Township 20 South, Range 27 East; thence East along the 

Section lines to the Northwest corner of Section 21, Township 20 South, Range 27 East; thence 

North along the Section line to the Northwest corner of the Southeast quarter of Section 16, 

Township 20 South, Range 27 East; thence East along the quarter section line to the Northeast 

corner of the Southeast quarter of Section 16, Township 20 South, Range 27 East; thence North 

along the Section line to the Northwest corner of Section 15, Township 20 South, Range 27 East; 

thence East along the Section line to the Northeast Corner of Section 14, Township 20 South, 

Range 27 East; thence South along the Section lines to the Southeast corner of Section 23, 

Township 20 South, Range 27 East; thence West along the Section line to the Southwest corner 

of the Southeast quarter of Section 23, Township 20 South, Range 27 East; thence South along 

the quarter section line to the Northwest corner of the Northeast quarter of Section 35, 
Appendix A 

St. Johns River Water Management District

227 

Township 20 South, Range 27 East; thence East along the Section line to the Northeast corner of 

Section 35, Township 20 South, Range 27 East; thence South along the Section line to the 

Southeast corner of Section 35, Township 20 South, Range 27 East; thence East along the Section 

line to the Southwest corner of the Southeast quarter of Section 36, Township 20 South, Range 

28 East, thence North along the quarter section line to the Northwest corner of the Southeast 

quarter of Section 36, Township 20 South, Range 27 East; thence East along the quarter section 

line to the Northeast corner of the Southeast quarter of Section 36, Township 20 South, Range 27 

East; thence North along the Section line to the Northwest corner of Section 31, Township 20 

South, Range 28 East; thence East along the Section lines to the Northeast corner of the 

Northwest quarter of Section 33, Township 20 South, Range 28 East; thence South along the 

quarter section lines to the Southeast corner of the Southwest quarter of Section 9, Township 21 

South, Range 28 East, thence East along the Section line to the Northeast corner of Section 16, 

Township 21 South, Range 28 East; thence South along the Section line to the Southeast corner 

of Section 16, Township 2 South, Range 28 East thence West along the Section line to the 

Southwest corner of the Southeast quarter of Section 16, Township 21 South, Range 28 East; 

thence South along the quarter section line to the Southeast corner of the Southwest quarter of 

Section 21, Township 21 South, Range 28 East; thence West along the Section line to the 

Southeast corner of Section 20, Township 21 South, Range 28 East; thence South along, the 

Section line to the Southeast corner of Section 32 Township 21 South, Range 28 East; thence 

West along, the Section line to the Southwest comer of the Southeast quarter of Section 32, 

Township 21 South, Range 28 East; thence South along the quarter section line to the Southwest 

corner of the Northeast quarter of Section 8, Township 22 South, Range 28 East; thence East 

along the quarter section line to the Southeast corner of the Northeast quarter of Section 8, 

Township 22 South, Range 28 East; thence South along the Section line to the Southeast corner 

of Section 8, Township 22 South, Range 28 East; thence West along the Section line to the 

Southeast corner of Section 7, Township 22 South, Range 28 East; thence South along the Section 

line to the Southeast corner of the Northeast quarter of Section 18, Township 22 South, Range 28 

East; thence West along the quarter section line to the Northeast corner of the Southeast quarter 

of Section 13, Township 22 South, Range 27 East; thence South along the Section line to the 

Southeast corner of Section 13, Township 22 South, Range 27 East; thence West along the 

Section line to the Southwest corner of the Southeast quarter of Section 13, Township 22 South, 

Range 27 East; thence South along the quarter section line to the Northwest quarter of the 

Northeast corner of Section 25, Township 22 South, Range 27 East; thence East along the Section 

lines to the Northeast corner of Section 29, Township 22 South, Range 28 East which is also the 

Point of Beginning.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1782 Section II - Proposed Rules

address. A copy of the letter Form DC3-247 will be maintained

in the offender file as documentation that the victim was

notified of this condition. Form DC3-247 is hereby

incorporated by reference. A copy of this form may be

obtained from the Forms Control Administrator, Office of the

General Counsel, 2601 Blair Stone Road, Tallahassee, Florida

32399-2500. The effective date of this form is December 18,

2001.

(2) Prohibition of Living Within 1000 Feet of Place Where

Children Regularly Congregate – If the court or releasing

authority imposes this condition of supervision, the supervisor

shall ensure:

(a) The officer has researched the offender’s residence

location for known places where children regularly congregate

to ensure compliance with the order of supervision and

paragraphs 948.03(5)(a) and (b), Florida Statutes; and

(b) The officer documents research conducted and

measurements obtained in the electronic case notes.

(3) Submission of Blood or Biological Specimens for

DNA Analysis – If the court or releasing authority imposes a

this condition for submission of blood specimens or other

biological specimens, or if the offender’s offense meets

statutory criteria of pursuant to s. 943.325 948.03(5)(a) and (b),

F.S., the officer shall verify that the offender’s specimens have

been collected and received by the Florida Department of Law

Enforcement:

(a) The circuit administrator shall ensure agreements are

formulated and upheld with DNA collection sites within the

circuit; and,

(b) The officer will ensure documentation is received from

the collection site verifying the DNA blood specimens were

drawn.

(4) through (5) No change.

(6) HIV Testing – If the court or releasing authority

imposes this condition of supervision the circuit administrator

shall identify and advise staff of ensure arrangements are made

to set up a testing locations in each circuit for sex offenders

required to submit to HIV testing.

(7) Pornographic Material – If the court or releasing

authority imposes a prohibition on viewing, owning, or

possessing any obscene, pornographic, or sexually stimulating

visual or auditory material, including telephone, electronic

media, computer programs or computer services that are

relevant to the offender’s deviant behavior pattern, the officer

shall ensure compliance by conducting walk-through searches

during the initial visit and, at a minimum, once quarterly

during subsequent visits to the offender’s residence, which can

lead to warrantless planned searches if pornographic material

is observed.

(8) Computer or Internet Restrictions – If the court or

releasing authority imposes a condition of supervision that

limits or prohibits use of computers or the internet, the officer

shall monitor compliance by:

(a) Conducting walk through searches during the initial

visit and, at a minimum, once quarterly during subsequent

visits to the offender’s residence to ensure the offender is in

compliance with the condition of supervision;

(b) If the officer verifies or suspects that the offender has

access to the internet, and this is prohibited as a condition of

supervision, the officer shall contact a correctional probation

officer or supervisor certified to conduct computer searches

FDLE or a local law enforcement officer certified to conduct

computer searches computer experts to investigate further.

Under no circumstances will an officer who has not been

certified in conducting computer searches be authorized to

touch the offender’s computer in an The officer will not

attempt to view icons for internet access or other graphic file

formats created by the Joint Photographic Experts Group,

unless the officer has successfully completed the Basic

Computer Data Recovery Class and has been authorized, in

writing, by the circuit administrator to conduct computer

searches.

Specific Authority 944.09 FS. Law Implemented 944.09, 947.1405, 948.03 FS.

History–New 12-18-01, Amended________ .

NAME OF PERSON ORIGINATING PROPOSED RULE:

Tina Hayes

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Michael W. Moore

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 2, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: March 22, 2002

WATER MANAGEMENT DISTRICTS

St. Johns River Water Management

RULE TITLE: RULE NO.:

Publications Incorporated by Reference 40C-4.091

PURPOSE AND EFFECT: The purpose and effect of this

proposed rule amendment is to amend section 11.7,

Applicant’s Handbook: Management and Storage of Surface

Waters, entitled “Lake Apopka Hydrologic Basin,” to establish

discharge limitations for total phosphorus for: (1) surface water

management systems (systems) located within the Lake

Apopka Hydrologic Basin, which discharge into Lake Apopka

or its tributaries; and (2) systems that cause an interbasin

diversion of water from another hydrologic basin to the Lake

Apopka Hydrologic Basin and discharge water to Lake

Apopka or its tributaries. The proposed rule amendments will

also establish water quantity limitations on diversions of water

to Lake Apopka or its tributaries from an area that does not

currently discharge water to Lake Apopka or its tributaries.

The proposed rule amendments revise Figure 11.0-5 in the

Applicant’s Handbook: Management and Storage of Surface

Waters to more accurately reflect the hydrologic boundaries of

the Lake Apopka Hydrologic Basin and to depict the Lake

Apopka Hydrologic Basin in relation to nearby cities and
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1783

public roads. Additionally, the proposed rule amendments will

establish requirements for monitoring the post-development

total phosphorus load discharged from the project area,

methodologies to determine the pre-development total

phosphorus load discharged from the project area, and an

annual inspection requirement.

SUMMARY: The proposed rule amendment would establish

post-development total phosphorus discharge limitations for

discharges to Lake Apopka or its tributaries, pursuant to

Section 373.461, F.S., create water quantity limitations on

diversions of water to Lake Apopka or its tributaries, revise

one figure and create a new figure depicting the Lake Apopka

Hydrologic Basin, create related monitoring requirements,

create methodologies for determining pre-development total

phosphorus load discharged from the project area, and

establish an annual inspection requirement.

SUMMARY OF STATEMENT OF ESTIMATED

REGULATORY COST: No statement of estimated regulatory

cost has been prepared. 

Any person who wishes to provide information regarding a

statement of estimated regulatory cost, or to provide a proposal

for a lower cost regulatory alternative, must do so in writing

within 21 days of this notice.

SPECIFIC AUTHORITY: 373.044, 373.113 FS.

LAW IMPLEMENTED: 373.413, 373.416, 373.418, 373.426,

373.461 FS.

A HEARING WILL BE HELD AT THE TIME, DATE AND

PLACE SHOWN BELOW:

TIME AND DATE: Following the regularly scheduled

Governing Board Meeting, which begins at 9:00 a.m., June 12,

2002

PLACE: St. Johns River Water Management District

Headquarters, 4049 Reid Street, Palatka, Florida 32177

THE PERSON TO BE CONTACTED REGARDING THE

PROPOSED RULE IS: Norma Messer, Rules Coordinator,

Office of General Counsel, St. Johns River Water Management

District, P. O. Box 1429, Palatka, Florida 32178-1429,

(386)329-4459, Suncom 860-4459, email

nmesser@sjrwmd.com.

THE FULL TEXT OF THE PROPOSED RULE IS:

40C-4.091 Publications Incorporated by Reference.

(1) The Governing Board hereby adopts by reference:

(a) Part I “Policy and Procedures,” Part II “Criteria for

Evaluation,” subsections 18.0, 18.1, 18.2, and 18.3 of Part III

and Appendix K “Legal Description Upper St. Johns River

Hydrologic Basin,” “Legal Description Ocklawaha River

Hydrologic Basin,” “Legal Description of the Wekiva River

Hydrologic Basin,” “Legal Description of the Econlockhatchee

River Hydrologic Basin,” “Legal Description of the Sensitive

Karst Areas Basin, Alachua County,” “Legal Description

Tomoka River Hydrologic Basin,” “Legal Description Spruce

Creek Hydrologic Basin,” “Legal Description of the Sensitive

Karst Areas Basin, Marion County,” and “Legal Descriptions

of the Lake Apopka Hydrologic Drainage Basin,” and

Appendix M “Regional Watersheds for Mitigation Banking,”

of the document entitled “Applicant's Handbook: Management

and Storage of Surface Waters,” effective ________ 10-11-01.

(b) through (c) No change.

(2) No change.

Specific Authority 373.044, 373.046(4), 373.113, 373.413, 373.4136, 373.414,

373.415, 373.416, 373.418, 373.421(2), 373.461(3) FS. Law Implemented

120.60, 373.016(2), 373.042, 373.0421, 373.046, 373.085, 373.086, 373.109.

373.406, 373.413, 373.4135, 373.4136 373.414, 373.4141, 373.415, 373.416,

373.417, 373.418 373.421(2)-(6), 373.423, 373.426, 373.461(3),

380.06(9),403.813(2) FS. History–New 12-7-83, Amended 10-14-84,

Formerly 40C- 4.091, Amended 5-17-87, Formerly 40C-4.0091, Amended

8-20-87, 10-1-87, 10-11-87, 11-26-87, 8-30-88, 1-1-89, 8-1-89, 10-19-89,

4-3-91, 9-25-91, 11-12-91, 3-1-92, 7-14-92, 9-8-92, 9-16-92, 11-12-92,

11-30-92, 1-6-93, 1-23-94, 2-27-94, 11-22-94, 10-3-95, 8-20-96, 11-25-98,

12-3-98, 1-7-99, 1-11-99, 8-21-00, 7-8.01, 10-11-01, ________.

APPLICANT’S HANDBOOK SECTION

11.0 Basin Criteria

Chapter 40C-41, F.A.C., and this section establish

additional criteria which are to be used in reviewing

applications for permits in certain hydrologic basins.

These basins are:

(a) Upper St. Johns River Hydrologic Basin

(b) Ocklawaha River Hydrologic Basin

(c) Wekiva River Hydrologic Basin

(d) Econlockhatchee River Hydrologic Basin

(e) Tomoka River Hydrologic Basin

(f) Spruce Creek Hydrologic Basin

(g) Sensitive Karst Areas Basin

(h) Lake Apopka Hydrologic Basin

See Figure 11.0-1 for a description of the areas

contained within the Upper St. Johns River Hydrologic

Basin, the Ocklawaha River Hydrologic Basin, the

Wekiva River Hydrologic Basin, and the

Econlockhatchee River Hydrologic Basin, the Tomoka

River Hydrologic Basin and the Spruce Creek

Hydrologic Basin. See Figures 11.0-2, 11.0-3, and

11.0-4 for a description of the areas contained within the

Sensitive Karst Areas Basin. See Figure 11.0-5 for a

description of the areas contained within the Lake

Apopka Hydrologic Basin. A description of the

Hydrologic Basin boundaries is available in Appendix

K.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1784 Section II - Proposed Rules

INSERT FIGURE 11.0-5
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1785

11.1 through 11.6 No change.

11.7 Lake Apopka Hydrologic Drainage Basin

(a) Pursuant to Section 373.461(3)(a), F.A.C., the

total phosphorus criterion for Lake Apopka is 55

parts per billion. To meet this total phosphorus

criterion, the applicant must provide reasonable

assurance of compliance with the following total

phosphorus discharge limitations and comply

with the relevant monitoring requirements in

Sections 11.7(b) through 11.7(e): This

phosphorus criterion shall be used to establish

phosphorous discharge limitations for all permits

within the Lake Apopka Drainage Basin

authorizing discharges, directly or indirectly, into

Lake Apopka, the Lake Level Canal, and the

McDonald Canal.

(1) Sites Within Lake Apopka Hydrologic Basin

Applicants required to obtain a permit pursuant to

Chapters 40C-4, 40C-40, 40C-42, or 40C-44,

F.A.C., for a surface water management system

located within the Lake Apopka Hydrologic

Basin shall demonstrate: (i) that the system

provides stormwater treatment equivalent to or

greater than any of the applicable stormwater

treatment options contained in Table 11.7-1 for

the removal of total phosphorus; (ii) that the

post-development total phosphorus load

discharged from the project area will not exceed

the pre-development total phosphorus load

discharged from the project area; or (iii) that the

system, under the soil moisture conditions

described in Section 10.3.8(a), will not discharge

water to Lake Apopka or its tributaries for the

100-year, 24-hour storm event. Systems

described under Section 11.7(a)(1)iii. shall be

considered to discharge to a land-locked lake that

must meet the criteria in Section 10.4.2. Any

alteration of a system originally permitted

pursuant to Section 11.7(a)(1)iii. which results in

an increase in discharge of water to Lake Apopka

or its tributaries shall be considered an interbasin

diversion that must meet the criteria in Sections

11.7(a)(2) and 11.7(e). 

(2) Interbasin Diversion of Water to Lake Apopka

Hydrologic Basin

Applicants required to obtain a permit pursuant to

Chapters 40C-4, 40C-40, 40C-42, or 40C-44,

F.A.C., for a surface water management system

that will cause the importation of water from

another hydrologic basin into the Lake Apopka

Hydrologic Basin shall not discharge any

phosphorus from the project area to Lake Apopka

or its tributaries, unless the applicant implements

measures to reduce the existing total phosphorus

load to Lake Apopka or its tributaries from another

existing source by at least an equivalent amount of

total phosphorus. The imported water shall consist

only of stormwater runoff. The imported water

shall not be discharged to Lake Apopka or its

tributaries when the water level of Lake Apopka is

in Zone A of the Lake Apopka Regulation

Schedule set forth in Table 11.7-2. All measures to

reduce existing phosphorous loads to Lake

Apopka or its tributaries must be constructed and

operating in compliance with the environmental

resource permit prior to any importation of water

into the Lake Apopka Hydrologic Basin. Measures

that reduce existing phosphorous loads to Lake

Apopka or its tributaries shall not include those

measures taken on the District’s land.

(b) Monitoring for Retention Systems

A surface water management system permitted

under Section 11.7(a)(1)i. which utilizes only

retention, shall be monitored as set forth in this

paragraph. Water elevations in such a system

shall be monitored from the date that construction

of the system is completed or any part of the

system is used for its intended purpose,

whichever is sooner. The monitoring shall

continue for three years following completion of

construction of the entire system, including all

associated residential, commercial,

transportation, or agricultural improvements. If

the results of the monitoring indicate that the

system is not recovering the treatment volume in

accordance with the permitted design, then the

permittee shall either perform maintenance on the

system, or obtain a modification to the permit and

implement measures, to bring the system into

compliance, and in either event the monitoring

shall continue for three years after the date the

system is brought into compliance.

(c) Monitoring for Systems Permitted Under Section

11.7(a)(1)iii.

A surface water management system permitted

under Section 11.7(a)(1)iii., shall be monitored as

set forth in this paragraph. Water elevations in

such a system shall be monitored from the date

that construction of the system is completed or

any part of the system is used for its intended

purpose, whichever is sooner. The monitoring in

such a system shall continue for ten years

following completion of construction of the

entire system, including all associated residential,

commercial, transportation, or agricultural

improvements. If the results of the monitoring
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1786 Section II - Proposed Rules

indicate that either the system is not recovering

storage in accordance with the permitted design

or causes water to be discharged to Lake Apopka

or its tributaries for events less than the 100-year,

24-hour storm event, then the permittee shall

either perform maintenance that brings the

system into compliance or obtain a modification

to the permit and implement measures to bring

the system into compliance, and in either event

the monitoring shall continue for three years after

the date the system is brought into compliance.

(d) Monitoring for Other Systems

A surface water management system, other than a

system described in Sections 11.7(b), 11.7(c) or

11.7(e), shall be monitored as set forth in this

paragraph. The total phosphorus load from the

project area shall be monitored from the date that

construction of such a system is completed or any

part of the system is used for its intended

purpose, whichever is sooner. The monitoring

shall continue for three years following

completion of construction of the entire system,

including all associated residential, commercial,

transportation, or agricultural improvements. If

the results of the monitoring indicate that

post-development total phosphorus loads exceed

pre-development total phosphorus loads, then the

permittee shall either perform maintenance on the

system, or obtain a modification to the permit and

implement measures, to reduce the total

phosphorus loads to no more than

pre-development levels, and in either event the

monitoring shall continue for three years after the

date the system is maintained or modified as

described herein.

(e) Monitoring for Interbasin Diversion of Water to

Lake Apopka Hydrologic Basin

A surface water management system described in

Section 11.7(a)(2) shall be monitored as set fort

in this paragraph. The total phosphorus load shall

be monitored from: (i) any system designed to

reduce the existing total phosphorus load to Lake

Apopka or its tributaries, and (ii) the system that

is importing water to the Lake Apopka

Hydrologic Basin. Monitoring of the system that

is importing water to the Lake Apopka

Hydrologic Basin shall commence from the date

that construction of such system is completed or

any part of the system is used for its intended

purpose, whichever is sooner. Monitoring of

systems designed to reduce the existing total

phosphorus load to Lake Apopka or its tributaries

shall commence from the date that construction

of such system is completed. Monitoring shall

continue for as long as water is imported from the

system to the Lake Apopka Hydrologic Basin. If

monitoring results indicate that the reductions in

total phosphorus load are less than that in the

imported water, then the permittee shall either

perform maintenance or obtain a permit

modification to bring the system(s) into

compliance.

(f) Determination of Pre-development Total

Phosphorus Loads

Pre-development total phosphorus loads shall be

based upon the land uses in place as of (effective

date) and shall be calculated by: monitoring the

total phosphorus loads from the project area for a

period of one year prior to construction,

alteration, abandonment, or removal of the

proposed or existing system; or calculating total

phosphorus loads for the same land uses from the

scientific literature. That calculation of

pre-development total phosphorus loads shall be

adjusted by interpolation or extrapolation to

reflect average annual rainfall conditions.

(g) Inspecting Systems

Systems subject to the inspection requirements in

subsection 40C-42.029(1), F.A.C., which were

permitted on or after (effective date) and which

were also subject to the phosphorus discharge

limitations in Section 11.7(a), shall be inspected

by the operation and maintenance entity within

one year after completion of construction and

every year thereafter.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1787

TABLE 11.7-1

STORMWATER TREATMENT CRITERIA TO ACHIEVE NO NET INCREASE IN POST-DEVELOPMENT LOADINGS 

WITHIN THE LAKE APOPKA HYDROLOGIC BASIN

1. Required dry retention volume (inches of runoff over project area)

2. Required dry retention volume (inches of runoff over project area) followed by wet detention with listed minimum

residence time

LAND USE

CATEGORY

DOMINANT 

SOIL

GROUP

RETENTION

ONLY1

RETENTION/

WET DETENTION

OPTION2

Low-Density

Residential

(max. 15% impervious)

A

B

C

D

2.75"

1.75"

1.25"

1.00"

1.00"/14 days

0.50"/14 days

0.50"/14 days

0.25"/14 days

Single-Family

Residential (max. 25% impervious)

A

B

C

D

2.50"

2.00"

1.75"

1.50"

1.00"/14 days

0.75"/14 days

0.75"/14 days

0.75"/14 days

Single-Family Residential (max. 40% Impervious) A

B

C

D

3.75”

2.50"

2.00"

1.75"

1.25"/14 days

0.75"/14 days

0.75"/14 days

0.50"/14 days

MultiFamily

Residential (max. 65% impervious)

A

B

C

D

4.00”

3.75"

3.00"

2.75"

2.50"/14 days

2.00"/14 days

1.50"/14 days

1.50"/14 days

Commercial (max. 80% impervious) A

B

C

D

4.00”

3.00"

2.50"

2.25"

2.75"/14 days

1.75"/14 days

1.50"/14 days

1.25"/14 days

Highway

(max. 50%

impervious)

A

B

C

D

4.00"

3.00"

2.50"

2.25"

2.00"/14 days

1.50"/14 days

1.25"/14 days

1.00"/14 days

Highway

(max. 75%

impervious)

A

B

C

D

4.00”

3.75"

2.75"

2.25"

2.75"/14 days

2.25"/14 days

1.75"/14 days

1.25"/14 days
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1788 Section II - Proposed Rules

ADD FIGURE 11.7.2
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1789

NAME OF PERSON ORIGINATING PROPOSED RULE:

Jeff Elledge, Director, Department of Water Resources, St.

Johns River Water Management District, P. O. Box 1429,

Palatka, Florida 32178-1429, (386)329-4347

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Governing Board of the St. Johns

River Water Management District

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 9, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: December 29, 2000

If any person decides to appeal any decision with respect to

any matter considered at the above listed public hearing, such

person may need to ensure that a verbatim record of the

proceeding is made to include testimony and evidence upon

which the appeal is to be based.

Anyone requiring special accommodation to participate in this

meeting is requested to advised the District at least 5 work days

before the meeting by contacting Linda Lorenzen,

(386)329-4262, or (386)329-4450(TDD).

WATER MANAGEMENT DISTRICTS

St. Johns River Water Management District

RULE TITLE: RULE NO.:

Publications Incorporated by Reference 40C-4.091

PURPOSE AND EFFECT: The St. Johns River Water

Management District proposes to amend the drainage basin

and regional watershed figures and tables which are part of the

Applicant’s Handbook: Management and Storage of Surface

Waters and are relevant to the review of applications for

environmental resource permits (ERP) and mitigation bank

permit applications. The District proposes to amend Figure

12.2.8-1 entitled “St. Johns River Water Management District

Drainage Basins” and the figure in Appendix M entitled “St.

Johns River Water Management District Regional Watersheds

for Mitigation Banking.” The drainage basins on Figure

12.2.8-1 define the geographical scope of the evaluation of

whether a regulated activity will cause unacceptable

cumulative impacts upon wetlands and other surface waters.

The regional watersheds in Appendix M are used in the

analysis of ecological benefits of proposed mitigation banks,

are considered in the establishment of mitigation bank service

areas, and are used as part of the determination of the number

of mitigation credits needed to offset a given wetland impact.

Specifically, the District proposes to amend Figure 12.2.8-1 by

revising the Northwest boundary between drainage basins 4, 5,

and 6, in the vicinity of Mill Dam Branch, Puncheon Gum

Swamp, and Pablo Creek in Duval County, and revising part of

the boundary between drainage basins 16 and 17 in the vicinity

of the Southeast corner of Flagler County (in Sections 17-19,

Township 14 South, Range 31 East). The District proposes to

amend Appendix M by revising the Northwest boundary

between regional watersheds 4, 5 and 6, in the vicinity of Mill

Dam Branch, Puncheon Gum Swamp, and Pablo Creek in

Duval County, and revising part of the boundary between

regional watersheds 16 and 17 in the vicinity of the Southeast

corner of Flagler County (in Section 17-19, Township 14

South, Range 31 East).

SUMMARY: The proposed rules amend the drainage basin

and regional watershed figures (Fig. 12.2.8-1 and figure in

Appendix M) in the Applicant’s Handbook: Management and

Storage of Surface Waters.

SUMMARY OF STATEMENT OF ESTIMATED

REGULATORY COST: None prepared.

Any person who wishes to provide information regarding the

statement of estimated regulatory costs, or to provide a

proposal for a lower cost regulatory alternative, must do so in

writing within 21 days of this notice.

IF REQUESTED WITHIN 21 DAYS OF THIS NOTICE, A

HEARING WILL BE HELD AT THE TIME, DATE AND

PLACE SHOWN BELOW:

TIME AND DATE: Following the regularly scheduled

Governing Board Meeting, which begins at 9:00 a.m., June 12,

2002

PLACE: St. Johns River Water Management District

Headquarters, 4049 Reid Street, Palatka, Florida 32177

SPECIFIC AUTHORITY: 373.044, 373.113, 373.414,

373.4136, 373.418 FS.

LAW IMPLEMENTED: 373.016(2), 373.413, 373.4135,

373.4136, 373.414(8), 373.416, 373.418, 373.426 FS.

THE PERSON TO BE CONTACTED REGARDING THE

PROPOSED RULE DEVELOPMENT IS: Norma Messer,

Rules Coordinator, Office of General Counsel, St. Johns River

Water Management District, P. O. Box 1429, Palatka, Florida

32178-1429, (386)329-4459, Suncom 860-4459, or email

nmesser@sjrwmd.com

THE FULL TEXT OF THE PROPOSED RULE IS:

40C-4.091 Publications Incorporated by Reference.

(1) The Governing Board hereby adopts by reference:
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1790 Section II - Proposed Rules

(a) Part I “Policy and Procedures,” Part II “Criteria for

Evaluation,” subsections 18.0, 18.1, 18.2, and 18.3 of Part III

and Appendix K “Legal Description Upper St. Johns River

Hydrologic Basin,” “Legal Description Ocklawaha River

Hydrologic Basin,” “Legal Description of the Wekiva River

Hydrologic Basin,” “Legal Description of the Econlockhatchee

River Hydrologic Basin,” “Legal Description of the Sensitive

Karst Areas Basin, Alachua County,” “Legal Description

Tomoka River Hydrologic Basin,” Legal Description Spruce

Creek Hydrologic Basin,” “Legal Description of the Sensitive

Karst Areas Basin, Marion County,” and “Legal Descriptions

of the Lake Apopka Drainage Basin,” and Appendix M

“Regional Watersheds for Mitigation Banking,” of the

document entitled “Applicant’s Handbook: Management and

Storage of Surface Waters,” effective ________ 10-11-01.

(b) through (c) No change.

(2) No change.

Specific Authority 373.044, 373.046(4), 373.113, 373.4136, 373.414, 373.415,

373.416, 373.418, 373.421, 373.461 FS. Law Implemented 120.60,

373.016(2), 373.042, 373.0421 373.046, 373.085, 373.086, 373.109, 373.406,

373.413, 373.4135, 373.4136, 373.414, 373.4141, 373.415, 373.416, 373.417,

373.418, 373.421(2)-(6), 373.423, 373.426, 373.461(3), 380.06(9), 403.813(2)

FS. History–New 12-7-83, Amended 10-14-84, Formerly 40C-4.091,

Amended 5-17-87, Formerly 40C-4.0091, Amended 8-20-87, 10-1-87,

10-11-87, 11-26-87, 8-30-88, 1-1-89, 8-1-89, 10-19-89, 4-3-91, 8-11-91,

9-25-91, 11-12-91, 3-1-92, 7-14-92, 9-8-92, 9-16-92, 11-12-92, 11-30-92,

1-6-93, 1-23-94, 2-27-94, 11-22-94, 10-3-95, 8-20-96, 11-25-98, 12-3-98,

1-7-99, 1-11-99, 8-21-00, 7-8-01, 10-11-01 , ________.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1791

ADD FIGURE 12.2.8-1
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1792 Section II - Proposed Rules

ADD APPENDIX M
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1793

NAME OF PERSON ORIGINATING PROPOSED RULE:

Thomas I. Mayton, Sr. Asst. General Counsel, Office of

General Counsel, St. Johns River Water Management District,

P. O. Box 1429, Palatka, Florida 32178-1429, (386)329-4108

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Governing Board of the St. Johns

River Water Management District

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 9, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: March 8, 2002

If any person decides to appeal any decision with respect to

any matter considered at the above listed public hearing, such

person may need to ensure that a verbatim record of the

proceeding is made to include testimony and evidence upon

which the appeal is to be based.

Anyone requiring special accommodation to participate in this

meeting is requested to advised the District at least 5 work days

before the meeting by contacting Ann Freeman,

(386)329-4101, or (386)329-4450(TDD).

WATER MANAGEMENT DISTRICTS

St. Johns River Water Management District

RULE TITLES: RULE NOS.:

Policy and Purpose 40C-41.011

Basin Boundaries 40C-41.023

Implementation 40C-41.033

Application of Chapter 40C-41.043

Exemptions 40C-41.051

Conditions for Issuance of Permits 40C-41.063

PURPOSE AND EFFECT: The purpose and effect of this

proposed rule amendment is to establish discharge limitations

for total phosphorus for surface water management systems

which are located in the Lake Apopka Hydrologic Basin or

which discharge into Lake Apopka or its tributaries. The

proposed rule amendments create new figure 41-5 that

generally depicts the areas contained within the Lake Apopka

Hydrologic Basin. Additionally, the proposed rule

amendments will establish an exemption from the discharge

limitations for stormwater management systems exempted

under existing Rule 40C-42.0225, F.A.C. Furthermore, the

proposed amendments will clarify that systems qualifying for a

noticed general permit under Chapter 40C-400, F.AC., are

exempted from the District’s basin rules.

SUMMARY: The proposed rule amendment would establish

post-development total phosphorus discharge limitations for

discharges to Lake Apopka or its tributaries, pursuant to

section 373.461, F.S., create two new figures depicting the

Lake Apopka Hydrologic Basin, and establish exemptions.

SUMMARY OF STATEMENT OF ESTIMATED

REGULATORY COST: No statement of estimated regulatory

cost has been prepared. 

Any person who wishes to provide information regarding a

statement of estimated regulatory cost, or to provide a proposal

for a lower cost regulatory alternative, must do so in writing

within 21 days of this notice.

SPECIFIC AUTHORITY: 373.044, 373.113, 373.414,

373.418 FS.

LAW IMPLEMENTED: 373.413, 373.416, 373.418, 373.426,

373.461 FS.

A HEARING WILL BE HELD AT THE TIME, DATE AND

PLACE SHOWN BELOW:

TIME AND DATE: Following the regularly scheduled

Governing Board Meeting, which begins at 9:00 a.m., June 12,

2002

PLACE: St. Johns River Water Management District

Headquarters, 4049 Reid Street, Palatka, Florida 32177

THE PERSON TO BE CONTACTED REGARDING THE

PROPOSED RULE IS: Norma Messer, Rules Coordinator,

Office of General Counsel, St. Johns River Water Management

District, P. O. Box 1429, Palatka, Florida 32178-1429,

(386)329-4459, Suncom 860-4459, email

nmesser@sjrwmd.com.

THE FULL TEXT OF THE PROPOSED RULE IS:

40C-41.011 Policy and Purpose. 

The rules in this chapter establish additional surface water

management standards and criteria for the Upper St. Johns

River Hydrologic Basin, the Ocklawaha River Hydrologic

Basin, the Wekiva River Hydrologic Basin, the

Econlockhatchee River Hydrologic Basin, the Tomoka River

Hydrologic Basin, the Spruce Creek Hydrologic Basin, and the

Sensitive Karst Areas Basin, and the Lake Apopka Hydrologic

Basin, which insure that development within the basins

incorporates the appropriate water quantity and water quality

control and other environmental measures necessary to protect

the integrity of the public investments in the basins and which

minimizes adverse impacts to the water resources of the

District. Standards and criteria delineated in this chapter are in

addition to those criteria specified in Chapters 40C-4, 40C-40,

and 40C-42, and 40C-44, F.A.C., in accordance with

40C-41.043, F.A.C. The standards, criteria, exemptions, and

additional requirements specified in this chapter are not

intended to supersede or rescind the terms and conditions of

any valid surface water management permit issued by the

District prior to the effective date of this chapter.

Specific Authority 373.044, 373.113, 373.171, 373.415 FS. Law Implemented

373.413, 373.415, 373.416, 373.418, 373.426, 373.461 FS. History–New

12-7-83, Amended 5-17-87, 8-30-88, 4-3-91, 9-25-91, 11-25-98, ________.

40C-41.023 Basin Boundaries.

(1) through (6) No change.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1794 Section II - Proposed Rules

Insert Figure 41-5
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1795

(7) The Lake Apopka Hydrologic Basin is that area

generally depicted in Figure 41-5 and defined in Applicant’s

Handbook, Appendix K as incorporated by reference in rule

40C-4.091, F.A.C.

Specific Authority 373.044, 373.113, 373.171 FS. Law Implemented 373.413,

373.416, 373.426 FS. History–New 12-7-83, Amended 5-17-87, 8-30-88,

4-3-91, 9-25-91, 11-25-98, ________.

40C-41.033 Implementation.

(1) The effective date of this chapter is December 7, 1983,

for the criteria of subsections 40C-41.063(1) and (2); May 17,

1987, for the standards of paragraphs 40C-41.063(3)(a) and

(b); August 30, 1988, for the standards and criteria of

paragraphs 40C-41.063(3)(c), (d) and (e); April 3, 1991, for the

standards and criteria in subsection 40C-41.063(5); and

September 25, 1991 for the criteria of subsections

40C-41.063(7), and 11-25-98 for the criteria of subsection

40C-41.063(6), and (effective date) for the standards and

criteria in subsection 40C-41.063(8).

(2) No change.

Specific Authority 373.044, 373.113, 373.171 373.415 FS. Law Implemented

373.413, 373.415, 373.416, 373.426, 373.461 FS. History–New 12-7-83,

Amended 5-17-87, 8-30-88, 4-3-91, 9-25-91, 11-25-98, ________.

40C-41.043 Application of Chapter.

(1) All projects located within the Upper St. Johns River

Hydrologic Basin, the Ocklawaha River Hydrologic Basin, the

Wekiva River Hydrologic Basin, or the Econlockhatchee River

Hydrologic Basin, the Tomoka River Hydrologic Basin, or the

Spruce Creek Hydrologic Basin, or the Lake Apopka

Hydrologic Basin, requiring permits pursuant to rule

40C-4.041, F.A.C., shall be constructed, operated, maintained,

altered, abandoned and removed in accordance with the

standards and criteria specified in rules 40C-41.063, and either

sections 40C-4.301 and 40C-4.302, or 40C-40.302, and

40C-41.063, F.A.C., unless specifically exempted in rule

40C-41.051, F.A.C., or otherwise provided in subsection

40C-41.043(3) or 40C-41.043(4), F.A.C. The most restrictive

criteria will be applicable unless the applicant provides

reasonable assurance that the purposes and intent of this

chapter and chapter 40C-4, F.A.C., will be fulfilled using

alternate criteria.

(2) No change.

(3) Stormwater management systems requiring permits

pursuant to rule 40C-42.022, F.A.C., that will be located within

the Lake Apopka Hydrologic Basin or will discharge water to

Lake Apopka or its tributaries, shall be constructed, operated,

maintained, altered, abandoned and removed in accordance

with the standards and criteria specified in rule 40C-42.023,

F.A.C., and subsection 40C-41.063(8), F.A.C.

(4) Agricultural surface water management systems

requiring permits pursuant to rule 40C-44.041, F.A.C., that

will be located within the Lake Apopka Hydrologic Basin or

will discharge water to Lake Apopka or its tributaries, shall be

constructed, operated, maintained, altered, abandoned and

removed in accordance with the standards and criteria

specified in Rule 40C-44.301, F.A.C., and subsection

40C-41.063(8), F.A.C.

Specific Authority 373.044, 373.113, 373.171, 373.415 FS. Law Implemented

373.413, 373.415, 373.416, 373.418, 373.426, 373.461 FS. History–New

12-7-83, Amended 5-17-87, 8-30-88, 4-3-91, 9-25-91, 10-3-95, 11-25-98,

________.

40C-41.051 Exemptions.

(1) No change.

(2) A single family dwelling unit The following systems

located wholly or partially within the Tomoka River

Hydrologic Basin or the Spruce Creek Hydrologic Basin,

provided the unit is not part of a larger common plan of

development or sale, is are exempted from the standards and

criteria in subsection 40C-41.063(6), F.A.C., and section 11.5,

Applicant’s Handbook: Management and Storage of Surface

Waters.:

(a) A single family dwelling unit provided the unit is not

part of a larger common plan of development or sale.

(b) Systems that qualify for a noticed general permit

pursuant to chapter 40C-400, F.A.C., and which comply with

the requirements of such noticed general permit.

(3) Stormwater management systems exempted in rule

40C-42.0225, F.A.C., which are either located wholly or

partially within the Lake Apopka Hydrologic Basin or which

discharge water to Lake Apopka or its tributaries, are exempted

from the standards and criteria in subsection 40C-41.063(8),

F.A.C.

(4) Systems that qualify for a noticed general permit under

Chapter 40C-400, F.A.C., are exempted from the standards and

criteria in Rule 40C-41.063, F.A.C., and Sections 11.0 – 11.7,

Applicant’s Handbook: Management and Storage of Surface

Waters.

Specific Authority 373.044, 373.113, 373.171 FS. Law Implemented 373.413,

373.416, 373.426, 373.461 FS. History–New 4-3-91, Amended 11-25-98,

________.

40C-41.063 Conditions for Issuance of Permits.

(1) through (7) No change.

(8) Any surface water management system that requires a

permit pursuant to Chapters 40C-4, 40C-40, 40C-42, or

40C-44, F.A.C., and that will be located within the Lake

Apopka Hydrologic Basin or will discharge water to Lake

Apopka or its tributaries, must comply with the requirements

of Section 11.7, Applicant’s Handbook: Management and

Storage of Surface Waters, adopted by reference in subsection

40C-4.091(1), F.A.C. 

Specific Authority 373.044, 373.113, 373.414, 373.415, 373.418 FS. Law

Implemented 373.413, 373.414. 373.415, 373.416, 373.418, 373.426 , 373.461

FS. History–New 12-7-83, Amended 5-17-87, 8-30-88, 8-1-89, 4-3-91,

9-25-91, 7-14-92, 10-3-95, 11-25-98, 10-11-01 , ________.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

1796 Section II - Proposed Rules

NAME OF PERSON ORIGINATING PROPOSED RULE:

Jeff Elledge, Director, Department of Water Resources, St.

Johns River Water Management District, P. O. Box 1429,

Palatka, Florida 32178-1429, (386)329-4347

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Governing Board of the St. Johns

River Water Management District

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 9, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: December 29, 2000

If any person decides to appeal any decision with respect to

any matter considered at the above listed public hearing, such

person may need to ensure that a verbatim record of the

proceeding is made to include testimony and evidence upon

which the appeal is to be based.

Anyone requiring special accommodation to participate in this

meeting is requested to advised the District at least 5 work days

before the meeting by contacting Linda Lorenzen at

(386)329-4262, or (386)329-4450(TDD).

WATER MANAGEMENT DISTRICTS

St. Johns River Water Management District

RULE TITLE: RULE NO.:

Requirements for Issuance 40C-42.023

PURPOSE AND EFFECT: The purpose and effect of this

proposed rule amendment is to establish discharge limitations

for total phosphorus for stormwater management systems

which are located in the Lake Apopka Hydrologic Basin or

which discharge into Lake Apopka or its tributaries.

SUMMARY: The proposed rule amendment would establish

post-development total phosphorus discharge limitations for

discharges to Lake Apopka or its tributaries, pursuant to

section 373.461, F.S.

SUMMARY OF STATEMENT OF ESTIMATED

REGULATORY COST: No statement of estimated regulatory

cost has been prepared. 

Any person who wishes to provide information regarding a

statement of estimated regulatory cost, or to provide a proposal

for a lower cost regulatory alternative, must do so in writing

within 21 days of this notice.

SPECIFIC AUTHORITY: 373.044, 373.113, 373.418 FS.

LAW IMPLEMENTED: 373.413, 373.416, 373.418, 373.426,

373.461 FS.

A HEARING WILL BE HELD AT THE TIME, DATE AND

PLACE SHOWN BELOW:

TIME AND DATE: Following the regularly scheduled

Governing Board Meeting, which begins at 9:00 a.m., June 12,

2002

PLACE: St. Johns River Water Management District

Headquarters, 4049 Reid Street, Palatka, Florida 32177

THE PERSON TO BE CONTACTED REGARDING THE

PROPOSED RULE IS: Norma Messer, Rules Coordinator,

Office of General Counsel, St. Johns River Water Management

District, P. O. Box 1429, Palatka, Florida 32178-1429,

(386)329-4459, Suncom 860-4459, email

nmesser@sjrwmd.com.

THE FULL TEXT OF THE PROPOSED RULE IS:

40C-42.023 Requirements for Issuance.

(1) To receive a general or individual permit under this

chapter the applicant must provide reasonable assurance based

on plans, test results and other information, that the stormwater

management system:

(a) through (c) No change.

(d) Meets any applicable basin criteria contained in Rule

40C-41.063(7) and (8), F.A.C. Chapter 40C-41, F.A.C.

(2) No change.

Specific Authority 373.044, 373.113, 373.171, 373.418 FS. Law Implemented

373.413, 373.416, 373.418, 373.426, 373.461 FS. History–New 9-25-91,

Amended 3-21-93, 10-3-95, __________.

NAME OF PERSON ORIGINATING PROPOSED RULE:

Jeff Elledge, Director, Department of Water Resources, St.

Johns River Water Management District, P. O. Box 1429,

Palatka, Florida 32178-1429, (386)329-4347

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Governing Board of the St. Johns

River Water Management District

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 9, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: December 29, 2000

If any person decides to appeal any decision with respect to

any matter considered at the above listed public hearing, such

person may need to ensure that a verbatim record of the

proceeding is made to include testimony and evidence upon

which the appeal is to be based.

Anyone requiring special accommodation to participate in this

meeting is requested to advised the District at least 5 work days

before the meeting by contacting Linda Lorenzen at

(386)329-4262, or (386)329-4450(TDD).

WATER MANAGEMENT DISTRICTS

St. Johns River Water Management District

RULE TITLES: RULE NOS.:

Performance Standards 40C-44.065

Publications Incorporated by Reference 40C-44.091

PURPOSE AND EFFECT: The purpose and effect of this

proposed rule amendment is to establish discharge limitations

for total phosphorus for agricultural surface water management

systems requiring a permit which are located in the Lake

Apopka Hydrologic Basin or which discharge into Lake

Apopka or its tributaries.
Florida Administrative Weekly Volume 28, Number 16, April 19, 2002

Section II - Proposed Rules 1797

SUMMARY: The proposed rule amendment would establish

post-development total phosphorus discharge limitations for

discharges to Lake Apopka or its tributaries, pursuant to

section 373.461, F.S.

SUMMARY OF STATEMENT OF ESTIMATED

REGULATORY COST: No statement of estimated regulatory

cost has been prepared.

Any person who wishes to provide information regarding a

statement of estimated regulatory cost, or to provide a proposal

for a lower cost regulatory alternative, must do so in writing

within 21 days of this notice.

SPECIFIC AUTHORITY: 373.044, 373.113, 373.418 FS.

LAW IMPLEMENTED: 373.413, 373.416, 373.418, 373.426,

373.461 FS.

A HEARING WILL BE HELD AT THE TIME, DATE AND

PLACE SHOWN BELOW:

TIME AND DATE: Following the regularly scheduled

Governing Board Meeting, which begins at 9:00 a.m., June 12,

2002.

PLACE: St. Johns River Water Management District

Headquarters, 4049 Reid Street, Palatka, Florida 32177

THE PERSON TO BE CONTACTED REGARDING THE

PROPOSED RULES IS: Norma Messer, Rules Coordinator,

Office of General Counsel, St. Johns River Water Management

District, P. O. Box 1429, Palatka, Florida 32178-1429,

(386)329-4459, Suncom 860-4459, email

nmesser@sjrwmd.com.

THE FULL TEXT OF THE PROPOSED RULES IS:

40C-44.065 Performance Standards.

(1) through (3) No change.

(4) Agricultural surface water management systems

requiring a permit, which will be located in the Lake Apopka

Hydrologic Basin or will discharge water to Lake Apopka or its

tributaries, must comply with the requirements of subsection

40C-41.063(8), F.A.C.

Specific Authority 373.044, 373.113, 373, 373.171, 373.416, 373.418 FS.

Law Implemented 373.016, 373.413, 373.416, 373.418, 373.426, 373.461 FS.

History–New 8-11-91, Amended 10-20-92, 7-4-93, 10-3-94,__________.

40C-44.091 Publications Incorporated by Reference.

(1) The Governing Board hereby adopts by reference Part

I "Policy and Procedures" and Part II "Criteria for Evaluation,"

of the document entitled "Applicant’s Handbook: Agricultural

Surface Water Management Systems, effective , _________

11-1-99.

(2) through (3) No change.

Specific Authority 373.044, 373.113, 373.171, 373.406, 373.416, 373.418 FS.

Law Implemented 373.406, 373.413, 373.416 , 373.418, 373.426, 373.461 FS.

History–New 10-20-92, Amended 7-4-93, 10-3-94, 11-1-99, ________.

APPLICANT’S HANDBOOK SECTION

10.2 Harm to the Water Resources Criteria

10.2.1 through 10.2.5 No change. 

10.2.6 Agricultural surface water management systems

requiring a permit which will be located in the Lake Apopka

Hydrologic Basin or which will discharge water to Lake Apopka

or its tributaries, must comply with the requirements of

subsection 40C-41.063(8), F.A.C., and Section 11.7, Applicant’s

Handbook: Management and Storage of Surface Waters.

NAME OF PERSON ORIGINATING PROPOSED RULE:

Jeff Elledge, Director, Department of Water Resources, St.

Johns River Water Management District, P. O. Box 1429,

Palatka, Florida 32178-1429, (386)329-4347

NAME OF SUPERVISOR OR PERSON WHO APPROVED

THE PROPOSED RULE: Governing Board of the St. Johns

River Water Management District

DATE PROPOSED RULE APPROVED BY AGENCY

HEAD: April 9, 2002

DATE NOTICE OF PROPOSED RULE DEVELOPMENT

PUBLISHED IN FAW: December 29, 2000

If any person decides to appeal any decision with respect to

any matter considered at the above listed public hearing, such

person may need to ensure that a verbatim record of the

proceeding is made to include testimony and evidence upon

which the appeal is to be based.

Anyone requiring special accommodation to participate in this

meeting is requested to advised the District at least 5 work days

before the meeting by contacting Linda Lorenzen at

(386)329-4262, or (386)329-4450(TDD).

WATER MANAGEMENT DISTRICTS

Southwest Florida Water Management District

RULE CHAPTER TITLE: RULE CHAPTER NO.:

Procedural 40D-1

RULE TITLES: RULE NOS.: 

Limiting Conditions 40D-1.6105

Forms and Instructions 40D-1.659

PURPOSE AND EFFECT: The purpose of the proposed

amendment to Rule 40D-1.659, F.A.C., is to adopt, by

incorporation, a form for use in the transfer of water use

permits to subsequent owners of the property on which the

permitted water withdrawal facilities are located. The purpose

of the proposed amendment to Rule 40D-1.6105, F.A.C., is to

allow subsequent land owners to transfer permits by submitting

a copy of the legally recorded deed to the property covered by

the permit in lieu of obtaining the signature of the original

permittee on the transfer form.

SUMMARY: The proposed amendments will adopt a form for

use in the transfer of water use permits and allow permits to be

transferred to subsequent land owners without the signature of

the original permittee on the transfer form.
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

228 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

MANAGEMENT AND STORAGE OF SURFACE WATERS 

RULE CHAPTER TITLE: RULE CHAPTER NO.: 

Management and Storage of Surface Waters 40C-4, F.A.C. 

RULE TITLE: RULE NO.: 

Publications Incorporated by Reference 40C-4.09 1, F.A.C. 

SUMMARY OF THE RULE:

This rule establishes a phosphorous criterion for Lake Apopka. 

SUMMARY OF THE HEARING

The amendments to Section 40C-4.091, F.A.C., were presented to and approved by the 

Governing Board of the St. Johns River Water Management District on June 11, 1996, for 

publication in the Florida Administrative Weekly. The amendments were published June 28, 

1996, in Volume 22, Number 26. A public hearing was not requested by the public and the 

District did not hold one of its own accord. 

FACTS AND CIRCUMSTANCES JUSTIFYING THE RULE

This rule establishes a phosphorous criterion for Lake Apopka pursuant to the mandate of 

Chapter 96-207, Laws of Florida (to be codified as section 373.461, Florida Statutes). This 

phosphorous criterion will be used to establish discharge limitations for all regulated activities 

within the Lake Apopka Drainage Basin that are permitted to discharge, directly or indirectly, 

into Lake Apopka, the Lake Level Canal, and the McDonald Canal.
Appendix A 

St. Johns River Water Management District

245 

ST. JOHNS RIVER WATER MANAGEMENT 

RULE TITLE: RULE NO.: 

Publications Incorporated by Reference 40C-4.091, F.A.C. 

40C-4.091 Publications Incorporated by Reference. 

 (1) The Governing Board hereby adopts by reference: 

 (a) Part I "Policy and Procedures," Part II "Criteria for Evaluation," 

subsections 18.0, 18.1, 18.2, and 18.3 of Part III and Appendix K "Legal Description 

Upper St. Johns River Hydrologic Basin," "Legal Description Ocklawaha River 

Hydrologic Basin," "Legal Description of the Wekiva River Hydrologic Basin," 

"Legal Description of the Econlockhatchee River Hydrologic Basin," "Legal 

Description of the Sensitive Karst Areas Basin, Alachua County," “Legal Description 

Tomoka River Hydrologic Basin,” “Legal Description Spruce Creek Hydrologic 

Basin,” "Legal Description of the Sensitive Karst Areas Basin, Marion County," and 

“Legal Descriptions of the Lake Apopka Hydrologic Drainage Basin,” and Appendix 

M “Regional Watersheds for Mitigation Banking,” of the document entitled 

"Applicant's Handbook: Management and Storage of Surface Waters," effective 

3-07-03 10-11-01. 

 (b) and (c) No change. 

 (2) No change. 

Specific Authority 373.044, 373.046(4), 373.113, 373.413, 373.4136, 373.414, 373.415, 

373.416, 373.418, 373.421(2), 373.461(3) FS. Law Implemented 120.60, 373.016(2), 

373.042, 373.0421, 373.046, 373.085, 373.086, 373.109. 373.406, 373.413, 373.4135, 

373.4136 373.414, 373.4141, 373.415, 373.416, 373.417, 373.418 373.421(2)-(6), 373.423, 

373.426, 373.461(3), 380.06(9),403.813(2) FS. History--New 12-7-83, Amended 10-14-

84, Formerly 40C- 4.091, Amended 5-17-87, Formerly 40C-4.0091, Amended 8-20-87, 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

246 

10-1-87, 10-11-87, 11-26-87, 8-30-88, 1-1-89, 8-1-89, 10-19-89, 4-3-91, 9-25-91, 11-12-91, 

3-1-92, 7-14-92, 9-8-92, 9-16-92, 11-12-92, 11-30-92, 1-6-93, 1-23-94, 2-27-94, 11-22-94, 

10-3-95, 8-20-96, 11-25-98, 12-3-98, 1-7-99, 1-11-99, 8-21-00, 7-8.01, 10-11-01, 3-07-03. 
Appendix A 

St. Johns River Water Management District

247 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

APPLICANT’S HANDBOOK 

MANAGEMENT AND STORAGE OF SURFACE WATERS 

11.0 Basin Criteria 

 Chapter 40C-41, F.A.C., and this section establish additional criteria which 

are to be used in reviewing applications for permits in certain hydrologic 

basins. These basins are: 

 (a) Upper St. Johns River Hydrologic Basin 

 (b) Ocklawaha River Hydrologic Basin 

 (c) Wekiva River Hydrologic Basin 

 (d) Econlockhatchee River Hydrologic Basin 

 (e) Tomoka River Hydrologic Basin 

 (f) Spruce Creek Hydrologic Basin 

 (g) Sensitive Karst Areas Basin 

 (h) Lake Apopka Hydrologic Basin 

 See Figure 11.0-1 for a description of the areas contained within the Upper 

St. Johns River Hydrologic Basin, the Ocklawaha River Hydrologic Basin, 

the Wekiva River Hydrologic Basin, and the Econlockhatchee River 

Hydrologic Basin, the Tomoka River Hydrologic Basin and the Spruce Creek 

Hydrologic Basin. See Figures 11.0-2, 11.0-3, and 11.0-4 for a description of 

the areas contained within the Sensitive Karst Areas Basin. See Figure 11.0-5 

for a description of the areas contained within the Lake Apopka Hydrologic 

Basin. A description of the Hydrologic Basin boundaries is available in 

Appendix K. 

Appendix A 

St. Johns River Water Management District

249 

11.1 through 11.6 No change. 

 11.7 Lake Apopka Hydrologic Drainage Basin 

 (a) Pursuant to section 373.461(3)(a), F.S.A.C., the total phosphorus criterion for 

Lake Apopka is 55 parts per billion. To meet this total phosphorus criterion, 

the applicant must provide reasonable assurance of compliance with the 

following total phosphorus discharge limitations and comply with the 

relevant monitoring requirements in section 11.7(b) and relevant inspection 

requirements of section 11.7(c): This phosphorus criterion shall be used to 

establish phosphorous discharge limitations for all permits within the Lake 

Apopka Drainage Basin authorizing discharges, directly or indirectly, into

Lake Apopka, the Lake Level Canal, and the McDonald Canal.

 (1) Sites Within Lake Apopka Hydrologic Basin

 Applicants required to obtain a permit pursuant to chapters 40C-4, 

40C-40, 40C-42, or 40C-44, F.A.C., for a surface water management

system located within the Lake Apopka Hydrologic Basin shall 

demonstrate: (i) that the system provides stormwater treatment 

equivalent to or greater than any of the applicable stormwater 

treatment options contained in Table 11.7-1 for the removal of total 

phosphorus; (ii) that the post-development total phosphorus load 

discharged from the project area will not exceed the pre-development 

total phosphorus load discharged from the project area; or (iii) that 

the system, under the soil moisture conditions described in section 

10.3.8(a), will not discharge water to Lake Apopka or its tributaries 

for the 100-year, 24-hour storm event. Systems described under 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

250 

section 11.7(a)(1)iii shall be considered to discharge to a land-locked 

lake that must meet the criteria in sections 10.4.1 and 10.4.2. Any 

alteration of a system originally permitted pursuant to section 

11.7(a)(1)iii which results in an increase in discharge of water to Lake 

Apopka or its tributaries shall be considered an interbasin diversion 

that must meet the criteria in sections 11.7(a)(2) and 11.7(b)(4).

 (2) Interbasin Diversion of Water to Lake Apopka Hydrologic Basin

 Applicants required to obtain a permit pursuant to chapters 40C-4, 40C-40, 

40C-42, or 40C-44, F.A.C., for a surface water management system that 

will cause the importation of water from another hydrologic basin into the 

Lake Apopka Hydrologic Basin shall not discharge any phosphorus from 

the project area to Lake Apopka or its tributaries, unless the applicant 

implements measures to reduce the existing total phosphorus load to Lake 

Apopka or its tributaries from another existing source by at least an 

equivalent amount of total phosphorus. The imported water shall consist 

only of stormwater runoff. The imported water shall not be discharged to 

Lake Apopka or its tributaries when the water level of Lake Apopka is in 

Zone A of the Lake Apopka Regulation Schedule set forth in Figure 11.7-

2. All measures to reduce existing phosphorous loads to Lake Apopka or 

its tributaries must be constructed and operating in compliance with the 

environmental resource permit prior to any importation of water into the 

Lake Apopka Hydrologic Basin. Measures that reduce existing 

phosphorous loads to Lake Apopka or its tributaries shall not include those 

measures taken on the District’s land.

(3) Methodology for Determining Total Phosphorus Loads.
Appendix A 

St. Johns River Water Management District

251 

Determination of Pre-Development Total Phosphorus Loads.

Pre-development total phosphorus loads shall be based upon the land uses 

in place as of March 7, 2003. For systems which have been constructed in 

accordance with a permit issued pursuant to chapters 40C-4, 40C-40, 40C42, or 40C-44, F.A.C., at the permit applicant’s option, the pre-development 

total phosphorus loads shall be based upon the land uses in place at the 

time the prior permit was issued. Pre-development total phosphorus loads 

shall be determined by: monitoring the total phosphorus loads from the 

project area for a period of one year prior to construction, alteration, 

abandonment, or removal of the proposed or existing system; calculating 

total phosphorus loads using the appropriate mean annual total phosphorus 

loadings in Table 11.7-3, or calculating total phosphorus loads for predevelopment land uses not listed in Table 11.7-3 using mean annual total 

phosphorus loadings from the scientific literature. When the predevelopment total phosphorus loads are determined by monitoring, the 

calculation of pre-development total phosphorus loads shall be adjusted by 

interpolation or extrapolation to reflect mean annual rainfall conditions.

 Determination of Post-Development Total Phosphorus Loads.

Post-development total phosphorus loads shall be based upon the land uses 

proposed in the permit application and shall be determined by: calculating 

total phosphorus loads using the appropriate mean annual total phosphorus 

loadings in Table 11.7-3 and then reducing the total phosphorus load 

according to the appropriate total phosphorus removal efficiency values 

for systems listed in Tables 11.7-4 through 11.7-33. For purposes of 

Tables 11.7-4 and 11.7-6 through 11.7-33, the term “retention” includes 

stormwater reuse and underdrain and underground exfiltration trench 

systems as those terms are defined in section 2.0 of the Applicant’s 

Handbook: Regulation of Stormwater Management Systems, Chapter 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

252 

40C-42, F.A.C., which is adopted by reference in section 40C-42.091(1), 

F.A.C. The calculation of total phosphorus loads for post-development 

land uses not listed in Table 11.7-3 or total phosphorus removal efficiency 

values for systems not listed in Tables 11.7-4 through 11.7-33 may be 

calculated using mean annual total phosphorus loadings and total 

phosphorus removal efficiency values from the scientific literature.

(b) Monitoring

 (1) Monitoring for Retention Systems.

 A surface water management system to be permitted under section 

11.7(a)(1)i which utilizes only retention, shall be monitored as set forth in 

this paragraph. Water elevations in such a system shall be monitored from 

the date that construction of the system is completed or any part of the 

system is used for its intended purpose, whichever is sooner. The 

monitoring shall continue for three years following completion of 

construction of the entire system, including all associated residential, 

commercial, transportation, or agricultural improvements. If the results of 

the monitoring indicate that the system is not recovering the treatment 

volume in accordance with the permitted design, then the permittee shall 

either perform maintenance on the system, or obtain a modification to the 

permit and implement measures, to bring the system into compliance, and 

in either event the monitoring shall continue for three years after the date 

the system is brought into compliance.

 (2) Monitoring for Systems Permitted Under Section 11.7(a)(1)iii.

 A surface water management system to be permitted under section 

11.7(a)(1)iii, shall be monitored as set forth in this paragraph. Water 

elevations in such a system shall be monitored from the date that 
Appendix A 

St. Johns River Water Management District

253 

construction of the system is completed or any part of the system is used 

for its intended purpose, whichever is sooner. The monitoring in such a 

system shall continue for ten years following completion of construction 

of the entire system, including all associated residential, commercial, 

transportation, or agricultural improvements. If the results of the 

monitoring indicate that either the system is not recovering storage in 

accordance with the permitted design or causes water to be discharged to 

Lake Apopka or its tributaries for events less than the 100-year, 24-hour 

storm event, then the permittee shall either perform maintenance that 

brings the system into compliance or obtain a modification to the permit 

and implement measures to bring the system into compliance, and in either 

event the monitoring shall continue for three years after the date the 

system is brought into compliance.

 (3) Monitoring for Other Systems

 A surface water management system to be permitted, other than a system 

described in sections 11.7(b)(1), 11.7(b)(2) or 11.7(b)(4), shall be 

monitored as set forth in this paragraph. Except as provided below, the 

total phosphorus load from the project area shall be monitored from the 

date that construction of such a system is completed or any part of the 

system is used for its intended purpose, whichever is sooner. The 

monitoring shall continue for three years following completion of 

construction of the entire system, including all associated residential, 

commercial, transportation, or agricultural improvements. If the results of 

the monitoring indicate that post-development total phosphorus loads 

exceed pre-development total phosphorus loads, then the permittee shall

either perform maintenance on the system, or obtain a modification to the 

permit and implement measures, to reduce the total phosphorus loads to no 

more than pre-development levels, and in either event the monitoring shall 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

254 

continue for three years after the date the system is maintained or modified 

as described herein.

 No monitoring shall be required under section 11.7(b)(3) when an 

applicant demonstrates that the system provides stormwater treatment 

equivalent to or greater than any of the applicable stormwater treatment 

options contained in Table 11.7-1 for the removal of total phosphorus. 

Alternatively, no monitoring shall be required under section 11.7(b)(3) 

when an applicant demonstrates that the post-development total phosphorus 

load discharged from the project area will not exceed the pre-development 

total phosphorus load discharged from the project area when determined 

using the appropriate mean annual total phosphorus loadings and total 

phosphorus removal efficiency values from Tables 11.7-3 through 11.7-33 .

 (4) Monitoring for Interbasin Diversion of Water to Lake Apopka Hydrologic 

Basin

 A surface water management system to be permitted under in section 

11.7(a)(2) shall be monitored as set forth in this paragraph. The total 

phosphorus load shall be monitored from: (i) any system designed to 

reduce the existing total phosphorus load to Lake Apopka or its tributaries, 

and (ii) the system that is importing water to the Lake Apopka Hydrologic 

Basin. Monitoring of the system that is importing water to the Lake 

Apopka Hydrologic Basin shall commence from the date that construction 

of such system is completed or any part of the system is used for its 

intended purpose, whichever is sooner. Monitoring of systems designed to 

reduce the existing total phosphorus load to Lake Apopka or its tributaries 

shall commence from the date that construction of such system is 

completed. Monitoring shall continue for as long as water is imported 

from the system to the Lake Apopka Hydrologic Basin. If monitoring 
Appendix A 

St. Johns River Water Management District

255 

results indicate that the reductions in total phosphorus load are less than 

that in the imported water, then the permittee shall either perform 

maintenance or obtain a permit modification to bring the system(s) into 

compliance.

 (c) Inspecting Systems

 Systems subject to the inspection requirements in subsection 40C-42.029(1), 

F.A.C., which were permitted on or after March 7, 2003 and which were also 

subject to the phosphorus discharge limitations in section 11.7(a), shall be 

inspected by the operation and maintenance entity within one year after 

completion of construction and every year thereafter.
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

256 

TABLE 11.7-1

STORMWATER TREATMENT CRITERIA TO ACHIEVE NO NET INCREASE IN POSTDEVELOPMENT LOADINGS WITHIN THE LAKE APOPKA HYDROLOGIC BASIN 

LAND USE 

CATEGORY 

HYDROLOGIC 

SOIL GROUP 

RETENTION1

ONLY2

RETENTION1/ 

WET 

DETENTION 

OPTION3

Low-Density 

Residential 

(max. 15% 

impervious) 

A 

B 

C 

D 

2.75" 

1.75" 

1.25" 

1.00" 

1.00"/14 days 

0.50"/14 days 

0.50"/14 days 

0.25"/14 days 

Single-Family 

Residential (max. 

25% impervious) 

A 

B 

C 

D 

2.75" 

2.00" 

1.75" 

1.50" 

1.00"/14 days 

0.75"/14 days 

0.75"/14 days 

 0.50"/14 days 

Single-Family 

Residential (max. 

40% impervious) 

A 

B 

C 

D 

3.75” 

3.00" 

2.00" 

1.50" 

1.25"/14 days 

 1.00"/14 days 

0.75"/14 days 

0.50"/14 days 

MultiFamily 

Residential (max. 

65% impervious) 

A 

B 

C 

D 

4.00” 

3.75" 

3.25" 

2.75" 

2.50"/14 days 

2.00"/14 days 

 1.75"/14 days 

1.50"/14 days 

Commercial (max. 

80% impervious) 

A 

B 

C 

D 

4.00” 

3.75" 

2.75" 

2.25" 

2.75"/14 days 

 2.25"/14 days 

1.50"/14 days 

1.25"/14 days 

Highway 

(max. 50% 

impervious) 

A 

B 

C 

D 

4.00" 

3.00" 

2.50" 

2.25" 

2.00"/14 days 

1.50"/14 days 

1.25"/14 days 

1.00"/14 days 

Highway 

(max. 75% 

impervious) 

A 

B 

C 

D 

4.00” 

3.75" 

2.75" 

2.25" 

2.75"/14 days 

2.25"/14 days 

1.75"/14 days 

1.25"/14 days 

 
Appendix A 

St. Johns River Water Management District

257 

 1. For purposes of this Table, the term “retention” includes stormwater reuse and underdrain 

and underground exfiltration trench systems as those terms are defined in section 2.0 of the 

Applicant’s Handbook: Regulation of Stormwater Management Systems, Chapter 40C-42, 

F.A.C., which is adopted by reference in section 40C-42.091(1), F.A.C.

 2 1. Required dry retention volume (inches of runoff over project area) 

 3 2. Required dry retention volume (inches of runoff over project area) followed by wet 

detention with listed minimum residence time 
Lake Apopka Regulation Schedule

68.067.567.066.566.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Elevation (Feet, NGVD)

Figure 11.7-2 

SWIM Plan for Lake Apopka 

St. Johns River Water Management District

258
Appendix A 

St. Johns River Water Management District

259 

TABLE 11.7-3 

MEAN ANNUAL LOADINGS OF TOTAL PHOSPHORUS FOR LAND USE TYPES IN THE 

LAKE APOPKA HYDROLOGIC BASIN

MEAN ANNUAL 

TOTAL PHOSPHORUS LOAD 

(kg/ac-yr) 

LAND USE 

CATEGORY 

HSG A HSG B HSG C HSG D 

Low-Density Residential (max. 15% 

impervious) 

0.069 0.135 0.215 0.284 

Single-Family Residential (max. 25% impervious) 0.227 0.286 0.383 0.465 

Single-Family Residential (max. 40% impervious) 0.250 0.333 0.446 0.536 

Multi-Family Residential (max. 65% impervious) 1.082 1.156 1.257 1.336 

Commercial (max. 80% impervious) 0.899 0.916 0.943 0.964 

Highway – max. 50% impervious 

Highway – max. 75% impervious 

0.710 

1.053 

0.756 

1.076 

0.817 

1.106 

0.871 

1.133 

Agriculture – Pasture 0.026 0.118 0.239 0.347 

Agriculture – Crops, Ornamentals, Nurseries 

Agriculture – Groves 

0.040 

0.007 

0.180 

0.036 

0.366 

0.079 

0.531 

0.123 

Open Land/Recreational/Fallow Groves and 

Cropland 

0.004 0.017 0.035 0.051 

Forests/Abandoned Tree Crops 0.004 0.021 0.045 0.070 

HSG = Hydrologic Soil Group 
TABLE 11.7-4 

REMOVAL EFFICIENCIES FOR TOTAL PHOSPHORUS IN DRY RETENTION SYSTEMS THAT MEET THE DESIGN AND 

PERFORMANCE CRITERIA IN RULE 40C-42.026, F.A.C.

HSG A HSG B HSG C HSG D LAND 

USE STANDARD OFW STANDARD OFW STANDARD OFW STANDARD OFW 

Low-Density 

Residential (max. 

15% impervious) 

78% 82% 67% 74% 63% 72% 60% 71% 

Single-Family 

Residential (max. 

25% impervious) 

90% 92% 78% 83% 69% 77% 65% 74% 

Single-Family 

Residential (max. 

40% impervious) 

84% 88% 72% 80% 65% 75% 63% 73% 

Multi-Family 

Residential (max. 

65% impervious) 

74% 83% 69% 79% 64% 75% 62% 74% 

Commercial (max. 

80% impervious) 

65% 76% 63% 74% 62% 72% 61% 71% 

Highway (max. 50% 

impervious) 

75% 85% 70% 80% 65% 76% 63% 74% 

Highway (max. 75% 

impervious) 

65% 76% 63% 74% 62% 72% 61% 71% 

Standard - Meets design and performance criteria in rule 40C-42.026, F.A.C., for discharges to Class III waters OFW - Meets design and performance criteria in rule 40C-42.026, F.A.C., for discharges to Class I, Class II, or Outstanding Florida Waters 

St. Johns River Water Management District

260

SWIM Plan for Lake Apopka 
Appendix A 

St. Johns River Water Management District

261 

TABLE 11.7-5 

REMOVAL EFFICIENCIES FOR TOTAL PHOSPHORUS IN WET DETENTION SYSTEMS 

THAT MEET THE DESIGN AND PERFORMANCE CRITERIA IN RULE 40C-42.026, F.A.C. 

Residence Time (days) Phosphorus Removal Efficiency (%) 

14 61.5 

21 64.5 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

262 

Table 11.7-6 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Low-Density Residential (max. 15% impervious) 

For Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 70 86 88 89 

0.50 78 90 92 92 

0.75 82 92 93 94 

1.00 85 93 94 95 

1.25 88 94 95 96 

1.50 90 95 96 96 

1.75 91 96 96 97 

2.00 92 96 97 97 

2.25 93 97 97 97 

2.50 93 97 97 98 

2.75 94 97 98 98 

3.00 95 98 98 98 

3.25 96 98 98 99 

3.50 97 98 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

263 

Table 11.7-7 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Low-Density Residential (max. 15% impervious) 

For Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 53 78 82 83 

0.50 67 85 87 88 

0.75 74 88 90 91 

1.00 79 91 92 93 

1.25 83 92 93 94 

1.50 85 93 94 95 

1.75 88 94 95 96 

2.00 89 95 96 96 

2.25 90 96 96 97 

2.50 92 96 97 97 

2.75 93 97 97 97 

3.00 93 97 97 98 

3.25 94 97 98 98 

3.50 94 97 98 98 

3.75 95 98 98 98 

4.00 95 98 98 98 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

264 

Table 11.7-8 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Low-Density Residential (max. 15% impervious) 

For Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 46 75 79 81 

0.50 63 83 86 87 

0.75 72 87 89 90 

1.00 78 90 91 92 

1.25 82 92 93 94 

1.50 85 93 94 95 

1.75 87 94 95 96 

2.00 89 95 96 96 

2.25 91 96 96 97 

2.50 92 96 97 97 

2.75 93 97 97 97 

3.00 94 97 97 98 

3.25 94 97 98 98 

3.50 95 98 98 98 

3.75 95 98 98 98 

4.00 96 98 98 98 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

265 

Table 11.7-9 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Low-Density Residential (max. 15% impervious) 

For Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 42 74 78 79 

0.50 60 82 85 86 

0.75 71 87 89 90 

1.00 78 90 91 92 

1.25 82 92 93 94 

1.50 85 93 94 95 

1.75 88 94 95 96 

2.00 90 95 96 96 

2.25 91 96 97 97 

2.50 92 96 97 97 

2.75 93 97 97 98 

3.00 94 97 98 98 

3.25 95 98 98 98 

3.50 95 98 98 98 

3.75 96 98 98 98 

4.00 96 98 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

266 

Table 11.7-10 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 25% impervious) 

For Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 82 92 93 94 

0.50 90 95 96 96 

0.75 92 96 97 97 

1.00 94 97 98 98 

1.25 95 98 98 98 

1.50 96 98 98 98 

1.75 96 98 99 99 

2.00 97 98 99 99 

2.25 97 99 99 99 

2.50 98 99 99 99 

2.75 98 99 99 99 

3.00 98 99 99 99 

3.25 99 99 99 99 

3.50 99 99 100 100 

3.75 99 100 100 100 

4.00 99 100 100 100 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

267 

Table 11.7-11 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 25% impervious) 

For Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 65 84 87 88 

0.50 78 90 91 92 

0.75 83 92 94 94 

1.00 87 94 95 95 

1.25 89 95 96 96 

1.50 91 96 96 97 

1.75 92 96 97 97 

2.00 93 97 97 98 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 95 98 98 98 

3.00 96 98 98 98 

3.25 96 98 99 99 

3.50 96 98 99 99 

3.75 97 99 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

268 

Table 11.7-12 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 25% impervious) 

For Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 54 79 82 84 

0.50 69 86 88 89 

0.75 77 90 91 92 

1.00 82 92 93 94 

1.25 85 93 94 95 

1.50 88 95 95 96 

1.75 90 95 96 96 

2.00 91 96 97 97 

2.25 92 97 97 97 

2.50 93 97 97 98 

2.75 94 97 98 98 

3.00 95 98 98 98 

3.25 96 98 98 98 

3.50 96 98 98 99 

3.75 96 98 99 99 

4.00 97 98 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

269 

Table 11.7-13 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 25% impervious) 

For Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 48 76 80 81 

0.50 65 84 86 87 

0.75 74 88 90 91 

1.00 81 91 93 93 

1.25 84 93 94 94 

1.50 87 94 95 95 

1.75 89 95 96 96 

2.00 91 96 96 97 

2.25 92 96 97 97 

2.50 93 97 97 98 

2.75 94 97 98 98 

3.00 95 98 98 98 

3.25 95 98 98 98 

3.50 96 98 98 98 

3.75 96 98 99 99 

4.00 97 98 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

270 

Table 11.7-14 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 40% impervious) 

For Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 71 90 93 94 

0.50 86 95 96 97 

0.75 90 97 98 98 

1.00 93 97 98 99 

1.25 94 98 99 99 

1.50 95 98 99 99 

1.75 96 99 99 99 

2.00 97 99 99 99 

2.25 97 99 99 99 

2.50 97 99 99 99 

2.75 98 99 99 100 

3.00 98 99 99 100 

3.25 98 99 100 100 

3.50 98 99 100 100 

3.75 99 100 100 100 

4.00 99 100 100 100 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

271 

Table 11.7-15 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 40% impervious) 

For Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 61 86 90 92 

0.50 77 92 94 95 

0.75 83 94 95 97 

1.00 87 95 97 97 

1.25 89 96 97 98 

1.50 91 97 98 98 

1.75 93 97 98 99 

2.00 94 98 98 99 

2.25 94 98 99 99 

2.50 95 98 99 99 

2.75 95 99 99 99 

3.00 96 99 99 99 

3.25 97 99 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

272 

Table 11.7-16 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 40% impervious) 

For Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 51 82 87 90 

0.50 68 88 91 93 

0.75 77 92 94 95 

1.00 83 94 95 96 

1.25 86 95 96 97 

1.50 89 96 97 97 

1.75 91 96 97 98 

2.00 92 97 98 98 

2.25 93 97 98 98 

2.50 94 97 98 98 

2.75 95 98 98 98 

3.00 95 98 98 99 

3.25 96 98 98 99 

3.50 96 98 99 99 

3.75 97 98 99 99 

4.00 97 98 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

273 

Table 11.7-17 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Single Family Residential (max. 40% impervious) 

For Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 48 82 87 90 

0.50 65 88 91 93 

0.75 75 91 94 95 

1.00 81 93 95 96 

1.25 85 95 96 97 

1.50 88 96 97 98 

1.75 90 96 97 98 

2.00 92 97 98 98 

2.25 93 97 98 99 

2.50 94 98 98 99 

2.75 94 98 99 99 

3.00 95 98 99 99 

3.25 96 98 99 99 

3.50 96 99 99 99 

3.75 97 99 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

274 

Table 11.7-18 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Multi Family Residential (max. 65% impervious) 

For Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 53 78 82 83 

0.50 74 88 90 91 

0.75 83 92 94 94 

1.00 88 95 96 96 

1.25 91 96 97 97 

1.50 93 97 97 98 

1.75 95 98 98 98 

2.00 95 98 98 98 

2.25 96 98 98 99 

2.50 97 98 99 99 

2.75 97 99 99 99 

3.00 97 99 99 99 

3.25 98 99 99 99 

3.50 98 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

275 

Table 11.7-19 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Multi Family Residential (max. 65% impervious) 

For Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 49 77 81 82 

0.50 69 86 88 89 

0.75 79 90 92 92 

1.00 85 93 94 95 

1.25 89 95 96 96 

1.50 91 96 96 97 

1.75 92 97 97 97 

2.00 94 97 98 98 

2.25 95 98 98 98 

2.50 95 98 98 98 

2.75 96 98 98 99 

3.00 96 98 99 99 

3.25 97 99 99 99 

3.50 97 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

276 

Table 11.7-20 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Multi Family Residential (max. 65% impervious) 

For Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 45 75 79 81 

0.50 64 84 86 87 

0.75 75 89 90 91 

1.00 82 92 93 94 

1.25 86 94 95 95 

1.50 89 95 96 96 

1.75 91 96 97 97 

2.00 93 97 97 97 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 95 98 98 98 

3.00 96 98 98 99 

3.25 96 98 99 99 

3.50 97 98 99 99 

3.75 97 98 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

277 

Table 11.7-21 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Multi-Family Residential (max. 65% impervious) 

for Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 43 74 78 80 

0.50 62 83 85 86 

0.75 74 88 90 91 

1.00 80 91 92 93 

1.25 85 93 94 95 

1.50 88 95 95 96 

1.75 90 96 96 97 

2.00 92 96 97 97 

2.25 93 97 97 98 

2.50 94 97 98 98 

2.75 95 98 98 98 

3.00 96 98 98 98 

3.25 96 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

278 

Table 11.7-22 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Commercial (max. 80% impervious) 

for Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 41 73 77 79 

0.50 65 84 86 87 

0.75 76 89 91 91 

1.00 83 92 93 94 

1.25 88 95 95 96 

1.50 91 96 96 97 

1.75 93 97 97 97 

2.00 94 97 98 98 

2.25 95 98 98 98 

2.50 96 98 98 99 

2.75 97 98 99 99 

3.00 97 99 99 99 

3.25 97 99 99 99 

3.50 98 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

279 

Table 11.7-23 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Commercial (max. 80% impervious) 

for Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 41 73 77 79 

0.50 63 83 86 87 

0.75 74 88 90 91 

1.00 81 92 93 93 

1.25 87 94 95 95 

1.50 89 95 96 96 

1.75 92 96 97 97 

2.00 93 97 97 98 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 96 98 98 99 

3.00 97 98 99 99 

3.25 97 99 99 99 

3.50 97 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

280 

Table 11.7-24 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Commercial (max. 80% impervious) 

for Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 39 72 77 78 

0.50 62 83 85 86 

0.75 72 87 89 90 

1.00 80 91 92 93 

1.25 85 93 94 95 

1.50 88 95 96 96 

1.75 91 96 97 97 

2.00 92 97 97 97 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 96 98 98 98 

3.00 96 98 99 99 

3.25 97 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

281 

Table 11.7-25 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Commercial (max. 80% impervious) 

for Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 39 72 76 78 

0.50 61 82 85 86 

0.75 71 87 89 90 

1.00 79 90 92 93 

1.25 84 93 94 94 

1.50 88 94 95 96 

1.75 90 96 96 97 

2.00 92 96 97 97 

2.25 94 97 98 98 

2.50 94 97 98 98 

2.75 95 98 98 98 

3.00 96 98 98 99 

3.25 97 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

282 

Table 11.7-26 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 50% impervious) 

for Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 54 79 82 83 

0.50 75 88 90 91 

0.75 85 93 94 95 

1.00 90 95 96 96 

1.25 92 97 97 97 

1.50 94 97 98 98 

1.75 95 98 98 98 

2.00 96 98 99 99 

2.25 97 99 99 99 

2.50 97 99 99 99 

2.75 98 99 99 99 

3.00 98 99 99 99 

3.25 98 99 99 99 

3.50 98 99 99 99 

3.75 98 99 99 99 

4.00 99 99 99 100 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

283 

Table 11.7-27 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 50% impervious) 

for Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 50 77 81 82 

0.50 70 86 89 89 

0.75 80 91 92 93 

1.00 86 93 94 95 

1.25 89 95 96 96 

1.50 91 96 97 97 

1.75 93 97 97 97 

2.00 94 97 98 98 

2.25 95 98 98 98 

2.50 96 98 98 98 

2.75 96 98 99 99 

3.00 97 98 99 99 

3.25 97 99 99 99 

3.50 97 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

284 

Table 11.7-28 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 50% impervious) 

for Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 47 76 79 81 

0.50 65 84 87 88 

0.75 76 89 91 91 

1.00 83 92 93 94 

1.25 87 94 95 95 

1.50 89 95 96 96 

1.75 91 96 97 97 

2.00 93 97 97 97 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 96 98 98 98 

3.00 96 98 98 99 

3.25 97 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

285 

Table 11.7-29 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 50% impervious) 

for Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 44 74 78 80 

0.50 63 83 86 87 

0.75 74 88 90 91 

1.00 81 91 93 93 

1.25 85 93 94 95 

1.50 89 95 96 96 

1.75 91 96 96 97 

2.00 92 96 97 97 

2.25 93 97 97 98 

2.50 94 97 98 98 

2.75 95 98 98 98 

3.00 96 98 98 99 

3.25 96 98 99 99 

3.50 97 98 99 99 

3.75 97 99 99 99 

4.00 97 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

286 

Table 11.7-30 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 75% impervious) 

for Hydrologic Soil Group A 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 41 73 77 79 

0.50 65 84 86 87 

0.75 76 89 91 91 

1.00 83 92 93 94 

1.25 88 95 95 96 

1.50 91 96 96 97 

1.75 93 97 97 97 

2.00 94 97 98 98 

2.25 95 98 98 98 

2.50 96 98 98 99 

2.75 97 98 99 99 

3.00 97 99 99 99 

3.25 97 99 99 99 

3.50 98 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

287 

Table 11.7-31 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 75% impervious) 

for Hydrologic Soil Group B 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 41 73 77 79 

0.50 63 83 86 87 

0.75 74 88 90 91 

1.00 81 91 93 93 

1.25 87 94 95 95 

1.50 89 95 96 96 

1.75 92 96 97 97 

2.00 93 97 97 98 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 96 98 98 99 

3.00 97 98 99 99 

3.25 97 99 99 99 

3.50 97 99 99 99 

3.75 98 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

288 

Table 11.7-32 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 75% impervious) 

for Hydrologic Soil Group C 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 39 72 77 78 

0.50 62 82 85 86 

0.75 72 87 89 90 

1.00 80 91 92 93 

1.25 85 93 94 95 

1.50 88 95 95 96 

1.75 91 96 97 97 

2.00 92 97 97 97 

2.25 94 97 98 98 

2.50 95 98 98 98 

2.75 96 98 98 98 

3.00 96 98 99 99 

3.25 97 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
Appendix A 

St. Johns River Water Management District

289 

Table 11.7-33 

Removal Efficiencies for Total Phosphorus Using Various 

Treatment Options in Highway (max. 75% impervious) 

for Hydrologic Soil Group D 

Annual Total P Removal (%) 

Retention / Wet Detention2 Retention Depth 

(inches) Dry Retention1

td=7 days td=14 days td=21 days 

0.25 38 72 76 78 

0.50 61 82 85 86 

0.75 71 87 89 90 

1.00 79 90 92 93 

1.25 84 93 94 94 

1.50 88 94 95 96 

1.75 90 96 96 97 

2.00 92 96 97 97 

2.25 94 97 98 98 

2.50 94 97 98 98 

2.75 95 98 98 98 

3.00 96 98 98 99 

3.25 97 98 99 99 

3.50 97 99 99 99 

3.75 97 99 99 99 

4.00 98 99 99 99 

1. Dry retention alone. 

2. Dry retention followed by wet detention with various residence times. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

290 

Complete Rewording of Appendix K 

APPENDIX K 

LEGAL DESCRIPTION 

LAKE APOPKA HYDROLOGIC BASIN 

Begin at the Northeast corner of Section 29, Township 22 South, Range 28 East; thence South along the 

Section lines to the Southeast corner of the Northeast quarter of Section 32, Township 22 South, Range 

28 East; thence west along the quarter section line to the Southeast corner of the Northwest quarter of 

Section 31, Township 22 South, Range 28 East; thence South along the quarter section line to the 

Southeast corner of the Southwest quarter of Section 31, Township 22 South, Range 28 East; thence 

West along the Section lines to the Southwest corner of the Southeast quarter of Section 36, Township 

22 South, Range 27 East; thence South along the quarter section line to the Southeast corner of the 

Southwest quarter of Section 1, Township 23 South, Range 27 East; thence West along the Section line 

to the Southeast corner of Section 2, Township 23 South, Range 27 East; thence South along the Section 

line to the Southeast corner of Section 11, Township 23 South, Range 27 East; thence West along the 

Section lines to the Southeast corner of the Southwest quarter of Section 7, Township 23 South, Range 

27 East; thence South along the quarter section line to the Southeast corner of the Northeast quarter of 

the Northwest quarter of Section 18, Township 23 South, Range 27 East; thence West along the south 

line of the Northeast quarter of the Northwest quarter and along the south line of the Northwest quarter 

of the Northwest quarter, to the Southwest corner of the Northwest quarter of the Northwest quarter of 

Section 18, Township 23 South, Range 27 East; thence North along the Section line to the Southwest 

corner of Section 7, Township 23 South, Range 27 East: thence West along the Section line to the 

Southwest corner of the Southeast quarter of Section 12, Township 23 South, Range 26 East; thence 

North along the quarter section line to the Southeast corner of the Southwest quarter of Section 1, 

Township 23 South, Range 26 East; thence West along the Section lines to the Southwest corner of the 

Southeast quarter of Section 6, Township 23 South, Range 26 East; thence North along the quarter 

section line to the Northwest corner of the Northeast quarter of Section 6, Township 23 South, Range 26 

East; thence East along the Section line to the Southwest corner of Section 32, Township 22 South, 

Range 26 East; thence North along the Section line to the Northwest corner of Section 32, Township 22 

South, Range 26 East; thence East along the Section line to the Southwest corner of Section 28, 

Township 22 South, Range 26 East; thence North along the Section line to the Southeast corner of the 
Appendix A 

St. Johns River Water Management District

291 

Northeast Quarter of Section 5, Township 22 South, Range 26 East; thence West along the quarter 

section line to the Southwest corner of the Northwest Quarter of Section 5, Township 22 South, Range 

26 East; thence North along the Section lines to the Northwest corner of Section 32, Township 21 

South, Range 26 East; thence East along the Section line to the Northeast corner of the Northwest 

quarter of Section 32, Township 21 South, Range 26 East; thence North along the quarter section lines 

to the Northwest corner of the Northeast quarter of Section 20, Township 21 South, Range 26 East; 

thence East along the Section line to the Southwest corner of Section 16, Township 21 South, Range 26 

East; thence North along the Section line to the Northwest corner of Section 16, Township 21 South, 

Range 26 East; thence East along the Section line to the Southwest corner of the Southeast quarter of 

Section 9, Township 21 South, Range 26 East; thence North along the quarter section line to the 

Northwest corner of the Southeast quarter of Section 4, Township 21 South, Range 26 East; thence 

West along the quarter section line to the Southwest corner of the Northwest quarter of Section 4, 

Township 21 South, Range 26 East; thence North along the Section line to the Northwest corner of 

Section 4, Township 21 South, Range 26 East and the South line of Section 33, Township 20 South, 

Range 26 East; thence West along said South line to the Southwest corner of said Section 33, Township 

20 South, Range 26 East; thence North along the section lines to the Northwest corner of Section 28, 

Township 20 South, Range 26 East; thence East along the section lines to the Southwest corner of the 

Southeast quarter of Section 24, Township 20 South, Range 26 East; thence North along the quarter 

section line to the Northwest corner of the Southeast quarter of Section 24, Township 20 South, Range 

26 East; thence East along the quarter section line to the Northeast corner of the Southeast quarter of 

Section 24, Township 20 South, Range 26 East; thence North along the Section line to the Northwest 

corner of Section 19, Township 20 South, Range 27 East; thence East along the Section lines to the 

Northwest corner of Section 21, Township 20 South, Range 27 East; thence North along the Section line 

to the Northwest corner of the Southwest quarter of Section 16, Township 20 South, Range 27 East; 

thence East along the quarter section line to the Northeast corner of the Southeast quarter of Section 16, 

Township 20 South, Range 27 East; thence North along the Section line to the Northwest corner of 

Section 15, Township 20 South, Range 27 East; thence East along the Section line to the Northeast 

corner of Section 14, Township 20 South, Range 27 East; thence South along the Section lines to the 

Southeast corner of Section 23, Township 20 South, Range 27 East; thence West along the Section line 

to the Southwest corner of the Southeast quarter of Section 23, Township 20 South, Range 27 East; 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

292 

thence South along the quarter section line to the Northwest corner of the Northeast quarter of Section 

35, Township 20 South, Range 27 East; thence East along the Section line to the Northeast corner of 

Section 35, Township 20 South, Range 27 East; thence South along the Section line to the Southeast 

corner of Section 35, Township 20 South, Range 27 East; thence East along the Section line to the 

Southwest corner of the Southeast quarter of Section 36, Township 20 South, Range 27 East; thence 

North along the quarter section line to the Northwest corner of the Southeast quarter of Section 36, 

Township 20 South, Range 27 East; thence East along the quarter section line to the Northeast corner of 

the Southeast quarter of Section 36, Township 20 South, Range 27 East; thence North along the Section 

line to the Northwest corner of Section 31, Township 20 South, Range 28 East; thence East along the 

Section lines to the Northeast corner of the Northwest quarter of Section 33, Township 20 South, Range 

28 East; thence South along the quarter section lines to the Southeast corner of the Southwest quarter of 

Section 9, Township 21 South, Range 28 East; thence East along the Section line to the Northwest 

corner of the Northeast quarter of the Northeast quarter of Section 16, Township 21 South, Range 28 

East; thence South along the quarter-quarter Section lines to the Southwest corner of the Southeast 

quarter of the Southeast quarter of Section 16, Township 21 South, Range 28 East; thence West along 

the Section line to the Southwest corner of the Southeast quarter of Section 16, Township 21 South, 

Range 28 East; thence South along the quarter section line to the Southeast corner of the Southwest 

quarter of Section 21, Township 21 South, Range 28 East; thence West along the Section line to the 

Southeast corner of Section 20, Township 21 South, Range 28 East; thence South along the Section line 

to the Southeast corner of Section 32, Township 21 South, Range 28 East; thence West along the 

Section line to the Southwest corner of the Southeast quarter of Section 32, Township 21 South, Range 

28 East; thence South along the quarter section line to the Southwest corner of the Northeast quarter of 

Section 8, Township 22 South, Range 28 East; thence East along the quarter section line to the 

Southeast corner of the Northeast quarter of Section 8, Township 22 South, Range 28 East; thence 

South along the Section line to the Southeast corner of Section 8, Township 22 South, Range 28 East; 

thence West along the Section line to the Southeast corner of Section 7, Township 22 South, Range 28 

East; thence South along the Section line to the Southeast corner of the Northeast quarter of Section 18, 

Township 22 South, Range 28 East; thence West along the quarter section line to the Northeast corner 

of the Southeast quarter of Section 13, Township 22 South, Range 27 East; thence South along the 

Section line to the Southeast corner of Section 13, Township 22 South, Range 27 East; thence West 
Appendix A 

St. Johns River Water Management District

293 

along the Section line to the Southwest corner of the Southeast quarter of Section 13, Township 22 

South, Range 27 East; thence South along the quarter section line to the Northwest corner of the 

Northeast quarter of Section 25, Township 22 South, Range 27 East; thence East along the Section lines 

to the Northeast corner of Section 29, Township 22 South, Range 28 East, and the Point of Beginning. 

NOTE: This description is based on U.S. Geological Survey 7.5 minute series quadrangle 

maps and St. Johns River Water Management District Hydrologic Basin maps. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

294 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

RULE TITLE: RULE No.: 

Policy and Purpose 40C-41.011, F.A.C. 

Basin Boundaries 40C-41.023, F.A.C. 

Implementation 40C-41.033, F.A.C. 

Application of Chapter 40C-41.043, F.A.C. 

Exemptions 40C-41.051, F.A.C. 

Conditions for Issuance of Permits 40C-41.063, F.A.C. 

40C-41.011 Policy and Purpose. The rules in this chapter establish additional surface water 

management standards and criteria for the Upper St. Johns River Hydrologic Basin, the 

Ocklawaha River Hydrologic Basin, the Wekiva River Hydrologic Basin, the 

Econlockhatchee River Hydrologic Basin, the Tomoka River Hydrologic Basin, the Spruce 

Creek Hydrologic Basin, and the Sensitive Karst Areas Basin, and the Lake Apopka 

Hydrologic Basin, which insure that development within the basins incorporates the 

appropriate water quantity and water quality control and other environmental measures 

necessary to protect the integrity of the public investments in the basins and which 

minimizes adverse impacts to the water resources of the District. Standards and criteria 

delineated in this chapter are in addition to those criteria specified in chapters 40C-4, 40C40, and 40C-42, and 40C-44, F.A.C., in accordance with 40C-41.043, F.A.C. The standards, 

criteria, exemptions, and additional requirements specified in this chapter are not 

intended to supersede or rescind the terms and conditions of any valid surface water 

management permit issued by the District prior to the effective date of this chapter. 

Specific Authority 373.044, 373.113, 373.171, 373.415 FS. Law Implemented 373.413, 

373.415, 373.416, 373.418, 373.426, 373.461 FS. History--New 12-7-83, Amended 5-17-87, 8-

30-88, 4-3-91, 9-25-91, 11-25-98,3-07-03. 
Appendix A 

St. Johns River Water Management District

295 

40C-41.023 Basin Boundaries. 

 (1) through (6) No change. 

Insert Figure 41-5 

 (7) The Lake Apopka Hydrologic Basin is that area generally depicted in Figure 

41-5 and defined in Applicant’s Handbook, Appendix K as incorporated by reference in 

rule 40C-4.091, F.A.C.

Specific Authority 373.044, 373.113, 373.171 FS. Law Implemented 373.413, 373.416, 373.426 

FS. History--New 12-7-83, Amended 5-17-87, 4-3-91, 9-25-91, 11-25-98, 3-07-03. 

40C-41.033 Implementation. 

 (1) The effective date of this chapter is December 7, 1983, for the criteria of 

subsections 40C-41.063(1) and (2); May 17, 1987, for the standards of paragraphs 40C41.063(3)(a) and (b); August 30, 1988, for the standards and criteria of paragraphs 40C41.063(3)(c), (d) and (e); April 3, 1991, for the standards and criteria in subsection 40C41.063(5); and September 25, 1991 for the criteria of subsection 40C-41.063(7), and 11-25- 

98 for the criteria of subsection 40C-41.063(6), and March 7, 2003, for the standards and 

criteria in subsection 40C-41.063(8). 

(2) No change. 

Specific Authority 373.044, 373.113, 373.171 373.415 FS. Law Implemented 373.413, 373.415, 

373.416, 373.426, 373.461 FS. History--New 12-7-83, Amended 5-17-87, 8-30-88, 4-3-91, 9-25-

91, 11-25-98, 3-07-03. 

40C-41.043 Application of Chapter. 

 (1) All projects located within the Upper St. Johns River Hydrologic Basin, the 

Ocklawaha River Hydrologic Basin, the Wekiva River Hydrologic Basin, or the 

Econlockhatchee River Hydrologic Basin, the Tomoka River Hydrologic Basin, or the 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

296 

Spruce Creek Hydrologic Basin, or the Lake Apopka Hydrologic Basin, requiring permits 

pursuant to rule 40C-4.041, F.A.C., shall be constructed, operated, maintained, altered, 

abandoned and removed in accordance with the standards and criteria specified in rules 

40C-41.063, and either sections 40C-4.301 and 40C-4.302, or 40C-40.302, and 40C-41.063,

F.A.C., unless specifically exempted in rule 40C-41.051, F.A.C., or otherwise provided in 

subsection 40C-41.043(3) or 40C-41.043(4), F.A.C. The most restrictive criteria will be 

applicable unless the applicant provides reasonable assurance that the purposes and intent 

of this chapter and chapter 40C-4, F.A.C., will be fulfilled using alternate criteria. 

 (2) No change. 

 (3) Stormwater management systems requiring permits pursuant to rule 40C42.022, F.A.C., that will be located within the Lake Apopka Hydrologic Basin or will 

discharge water to Lake Apopka or its tributaries, shall be constructed, operated, 

maintained, altered, abandoned and removed in accordance with the standards and 

criteria specified in rule 40C-42.023, F.A.C., and subsection 40C-41.063(8), F.A.C.

 (4) Agricultural surface water management systems requiring permits pursuant 

to rule 40C-44.041, F.A.C., that will be located within the Lake Apopka Hydrologic Basin 

or will discharge water to Lake Apopka or its tributaries, shall be constructed, operated, 

maintained, altered, abandoned and removed in accordance with the standards and 

criteria specified in rule 40C-44.301, F.A.C., and subsection 40C-41.063(8), F.A.C.

Specific Authority 373.044, 373.113, 373.171, 373.415 FS. Law Implemented 373.413, 

373.415, 373.416, 373.418, 373.426, 373.461 FS. History--New 12-7-83, Amended 5-17-87, 8-

30-88, 4-3-91, 9-25-91, 10-3-95, 11-25-98, 3-07-03. 

40C-41.051 Exemptions. 

 (1) No change. 
Appendix A 

St. Johns River Water Management District

297 

 (2) A single family dwelling unit The following systems located wholly or 

partially within the Tomoka River Hydrologic Basin or the Spruce Creek Hydrologic 

Basin, provided the unit is not part of a larger common plan of development or sale, is are

exempted from the standards and criteria in subsection 40C-41.063(6), F.A.C., and section 

11.5, Applicant’s Handbook: Management and Storage of Surface Waters.:

 (a) A single family dwelling unit provided the unit is not part of a larger 

common plan of development or sale.

 (b) Systems that qualify for a noticed general permit pursuant to chapter 40C400, F.A.C., and which comply with the requirements of such noticed general permit.

 (3) Stormwater management systems exempted in rule 40C-42.0225, F.A.C., 

which are either located wholly or partially within the Lake Apopka Hydrologic Basin or 

which discharge water to Lake Apopka or its tributaries, are exempted from the standards 

and criteria in subsection 40C-41.063(8), F.A.C.

 (4) Systems that qualify for a noticed general permit under Chapter 40C-400, 

F.A.C., are exempted from the standards and criteria in Rule 40C-41.063, F.A.C., and 

Sections 11.0 – 11.7, Applicant’s Handbook: Management and Storage of Surface Waters.

Specific Authority 373.044, 373.113, 373.171 FS. Law Implemented 373.413, 373.416, 

373.426, 373.461 FS. History--New 4-3-91, Amended 11-25-98, 3-07-03. 

40C-41.063 Conditions for Issuance of Permits. 

 (1) through (7) No change. 

 (8) Any surface water management system that requires a permit pursuant to 

Chapters 40C-4, 40C-40, 40C-42, or 40C-44, F.A.C., and that will be located within the Lake 

Apopka Hydrologic Basin or will discharge water to Lake Apopka or its tributaries, must 

comply with the requirements of Section 11.7, Applicant’s Handbook: Management and 

Storage of Surface Waters, adopted by reference in subsection 40C-4.091(1), F.A.C. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

298 

Specific Authority 373.044, 373.113, 373.414, 373.415, 373.418 FS. Law Implemented 

373.413, 373.414. 373.415, 373.416, 373.418, 373.426, 373.461 FS. History--New 12-7-83, 

Amended 5-17-87, 8-30-88, 8-1-89, 4-3-91, 9-25-91, 7-14-92, 10-3-95, 11-25-98, 10-11-01,

3-07-03. 
Appendix A 

St. Johns River Water Management District

299 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

RULE TITLE: 

 RULE NO.: 

Requirements for Issuance 40C-42.023, F.A.C. 

40C-42.023 Requirements for Issuance. 

 (1) To receive a general or individual permit under this chapter the applicant must 

provide reasonable assurance based on plans, test results and other information, that 

the stormwater management system: 

 (a) through (c) No change. 

 (d) Meets any applicable basin criteria contained in Rule 40C-41.063(7) and (8), 

F.A.C. Chapter 40C-41, F.A.C. 

 (2) No change. 

Specific Authority 373.044, 373.113, 373.171, 373.418 FS. Law Implemented 373.413, 

373.416, 373.418, 373.426, 373.461 FS. History--New 9-25-91. Amended 3-21-93, 10-3-95, 3-

07-03. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

300 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

RULE TITLE: RULE NO.: 

Performance Standards 40C-44.065, F.A.C. 

Publications Incorporated by Reference 40C-44.091, F.A.C. 

40C-44.065 Performance Standards 

 (1) through (3) No change. 

 (4) Agricultural surface water management systems requiring a permit, which 

will be located in the Lake Apopka Hydrologic Basin or will discharge water to Lake 

Apopka or its tributaries, must comply with the requirements of subsection 40C-41.063(8), 

F.A.C.

Specific Authority 373.044, 373.113, 373, 373.171, 373.416, 373.418 FS. Law Implemented 

373.016, 373.413, 373.416, 373.418, 373.426, 373.461 FS. History—New8-11-91. Amended 

10-20-92, 7-4-93, 10-3-94, 3-07-03. 

40C-44.091 Publications Incorporated by Reference. 

 (1) The Governing Board hereby adopts by reference Part I "Policy and 

Procedures" and Part II "Criteria for Evaluation," of the document entitled "Applicant's 

Handbook: Agricultural Surface Water Management Systems, effective, 3-07-03 11-1-99. 

(2) and (3) No change. 

Specific Authority 373.044, 373.113, 373.171, 373.406, 373.416, 373.418 FS. Law 

Implemented, 373.406, 373.413, 373.416, 373.418, 373.426, 373.461 FS. History--New 10-20-

92, 7-4-93, 10-3-9, 11-1-99, 3-07-03. 
Appendix A 

St. Johns River Water Management District

301 

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT 

APPLICANT’S HANDBOOK 

AGRICULTURAL SURFACE WATER MANAGEMENT SYSTEMS 

APPLICANT’S HANDBOOK SECTION 

10.2 Harm to the Water Resources Criteria 

 10.2.1 through 10.2.5 No Change 

 10.2.6 Agricultural surface water management systems requiring a permit which 

will be located in the Lake Apopka Hydrologic Basin or which will 

discharge water to Lake Apopka or its tributaries, must comply with the 

requirements of subsection 40C-41.063(8), F.A.C., and Section 11.7, 

Applicant’s Handbook: Management and Storage of Surface Waters.
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

302 
Appendix B 

St. Johns River Water Management District

303 

APPENDIX B—CHRONOLOGY OF LAKE APOPKA

Year(s) Event

1821 Seminole village located near lake 

1845 First township plats recorded 

1893 Apopka-Beauclair Canal dredged from Lake Apopka through Lakes Dora 

and Eustis to the Ocklawaha River, lowering the water surface of Lake 

Apopka by 1.2 m (4 ft) 

1915 Apopka-Beauclair Canal enlarged and the lake level lowered to 63 ft 

NGVD 29. WWI prompted the planting of potatoes on the north shore 

1917 The north shore no longer farmed because of crop failures 

1920 Lake Apopka described in reports as clear, with a luxuriant growth of rooted 

aquatic plants and good fishing 

1922 Sewage discharge begins from Winter Garden 

1924 Wastewater discharges begin from fresh fruit preparation 

1926 A destructive hurricane hits, and north shore farms revert to marshland 

1936 Lake Apopka elevation reaches a high of 69.3 ft NGVD 29 in October 

1941 The Zellwood Drainage and Water Control District (ZDWCD) created by 

special act of the Legislature. Levee constructed on the north side of the lake. 

Aerial photography indicates rooted, submersed plants and clear water 

1942 Drainage water discharges begin from muck farms. First north shore peat 

farms operating. Lake elevation reaches a low of 65.9 ft NGVD 29 

1942–47 Muck farms expand to 3,137 ha (7,745 ac) 

1946 Single-strength citrus juice production begins, with wastewater discharged to 

Lake Apopka. A heavy growth of pondweed (Potamogeton sp.) located 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

304 

Year(s) Event

approximately 180 m from shore and extending across the entire lake, except 

where the water depth exceeds 2.4 m (8 ft), covering an area of 8,100 ha 

(20,000 ac). Water hyacinth very thick around the edge of the shore, which 

instigates a hyacinth control program, resulting in an unusually large 

number of decaying plants in the lake 

1947 The first algal blooms confirmed by aerial photography in March. 35% of fish 

are gamefish, and 20% are gizzard shad. The lake reaches an elevation of 68.7 

ft NGVD 29 in September and October 

1948 Wastewater discharges from citrus concentrate production begin. Herbicide 

(2-4-D) treatments of water hyacinth begin. Apopka-Beauclair Canal 

upgraded; 57% of fish are gamefish 

1948–50 Disappearance of rooted aquatic vegetation, frequent algal blooms. The fish 

population increases ten-fold; large catches reported—69% gamefish. 

Pondweed completely eradicated 

1951 Average annual gross income of fish camps about $37,000 each 

1952 Temporary control structure placed in Apopka-Beauclair Canal. Lake-level 

stabilization program begun 

1956 A permanent lock-and-dam structure placed in Apopka-Beauclair Canal, and 

water level regulated at 66.5-67.5 ft NGVD 29. Lake elevation reaches 64.04 ft 

NGVD 29 on August 12 due to effects of drainage and drought. Twenty-one 

fish camps in operation 

1957 Rough fish (mostly gizzard shad) comprise 82% of the fish population. 

Selective poisoning of gizzard shad and threadfin shad (1,587 tonnes or 1,750 

tons) with Rotenone. Dense phytoplankton bloom follows 

1958 Selective poisoning of gizzard shad and threadfin shad (4,535 tonnes or 5,000 

tons). Dense phytoplankton bloom follows. Apopka-Beauclair Canal 

deepened 

1959 Selective poisoning of gizzard shad and threadfin shad (2,948 tonnes or 3,250 

tons). Dense phytoplankton bloom follows. An aquatic survey undertaken. A 

thick band of panicgrass, maidencane, spike rush, and eelgrass (Panicum 
Appendix B 

St. Johns River Water Management District

305 

Year(s) Event

geminatum, Panicum hemitomon, Eleocharis sp., and Vallisneria americana, 

respectively) borders most of the lakeshore from Winter Garden west to 

Oakland. Majority of the northern shore devoid of emergent vegetation. 

Winter Garden wastewater treatment plant capacity enlarged to 1 mgd 

1962 Gizzard shad comprise only 30% of the fish biomass, with gamefish 

rebounding at 50%. A dark brown to orange odorous sludge blanket enters 

the lake from the canal discharging citrus processing waste. A report of the 

water quality of Lake Apopka, by the Orange County Health Department, 

calculates a biochemical oxygen demand loading of 8,400 pounds per day or 

equivalent to a population of 49,500 from four packing houses and the 

Winter Garden Citrus Products Cooperative Processing Plant. 

Approximately 54 tonnes (60 tons) of fish, frogs, snakes, and turtles killed, 

cause unknown. The algal bloom predominately Botryococcus sp. 

1963 Large fish kill in May. Approximately 4,500–9,000 tonnes of rough fish, 250 

tonnes of gamefish (5,000–10,000 tons and 250 tons, respectively) killed. 

Approximately 7,300 ha (18,000 ac) of farmland under cultivation on the 

north shore of the lake. USFWS and the U.S. Public Health Service report 160 

ppm DDT and DDE and 50 ppm TDE in the fat of largemouth bass and 7 

ppm DDT and DDE and 8 ppm TDE in the flesh of bluegill collected from the 

lake in June 

1965 Nine fish camps in operation, with an average annual gross income of about 

$11,000 each. The Florida State Board of Health estimates the spawning and 

feeding grounds to be less than 810 ha (2,000 ac) of the lake’s 12,150 ha 

(30,000 ac). A moderate increase in vegetation (Potamogeton and Vallisneria) 

along the shore attributed to heavy rainfalls improving light penetration. The 

lake at elevation 66.2 ft NGVD 29 on October 21 

1966 The Florida State Board of Health files an injunction against Winter Garden 

Citrus Products Cooperative Processing Plant. Large fish kill reported. Water 

samples taken in Apopka-Beauclair Canal reveal 60,000 ppm DDD and other 

DDT-related metabolites, with traces of dieldrin and lindane 

1967 Governor Claude Kirk appoints a technical committee consisting of 16 

federal, state, and local agencies and advisors. A citizens committee forms to 

complement the work of the technical committee. Water quality restoration 

standards set. Laboratory opens at Fisherman’s Paradise Fish Camp, staffed 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

306 

Year(s) Event

by permanent and temporary personnel. Routine water quality sampling 

begun. An estimated 9,720 ha (24,000 ac) (double cropping) of vegetable 

crops harvested. Water hyacinth spraying ceases, except when navigation 

threatened 

1968 Lake Apopka Trust Fund enacted by Orange County Commission, funded by 

Orange and Lake counties. Restoration project placed under authority of 

Florida Air and Water Pollution Control Commission. Farms hire 

engineering consultants 

1969 Winter Garden Citrus Products Cooperative Processing Plant adds nutrient 

removal process to treat 2.0 mgd of strong waste 

1970 Gizzard shad constitutes 82% of the fish population 

1971 Experimental gravity drawdown. Lake level lowered 2.1 ft, from 66.5 to 64.4 

ft NGVD 29. Alligator, turtle, bird, snake, and fish mortality 

1973 A vegetation survey finds only a few sparse patches of stonewort (Chara) and 

Panicum on the lakeshore from Winter Garden west to Oakland 

1974 Four fish camps remain 

1977 Direct citrus processing wastewater discharges to lake end. Peat mine begins 

discharge from Pine Island, adjacent to Gourd Neck 

1980 Direct sewage discharges end as the Winter Garden Pollution Control 

Facility constructs a percolation/evaporation system. A spill from Tower 

Chemical Company contaminates the drainage into Gourd Neck in the 

southwestern portion of the lake with copper and pesticides from a 

wastewater pond 

1981 Report published by the University of Florida indicates an increase in 

eutrophication over a four-year period. A major decline in juvenile alligators 

observed on Lake Apopka 

1985 Lake Apopka Restoration Act enacted which creates the Lake Apopka 

Restoration Council (LARC). A total of $2.265 million is appropriated to 

initiate feasibility studies, evaluate restoration techniques, and develop a 
Appendix B 

St. Johns River Water Management District

307 

Year(s) Event

nutrient budget. SJRWMD issues Intent to Deny for Duda and ZDWCD 

consumptive use applications and requests Cease and Desist Order and 

criminal charges 

1986 Initiation of Comprehensive Pilot Projects by SJRWMD 

1987 Passage of the SWIM Act. Lake Apopka named a priority water body, one of 

initial seven statewide in need of restoration 

1988 Initiation of the Marsh Flow-Way Restoration Project. FDEP delegates 

authority to regulate muck farm discharges to SJRWMD. SJRWMD sues A. 

Duda & Sons, Inc. (Duda) and ZDWCD for operating without valid 

discharge permits. SJRWMD signs a consent order with Duda to reduce 

nutrient loading. On November 16, SJRWMD acquires approximately 633 ha 

(1,563 ac) from Foley and Eric Hooper for $5 million. Approximately 552 ha 

(1,363 ac) of this acquisition traded to Duda for $300,000 and 749 ha (1,850 ac) 

contained in their Clay Island Farm. At the same time, Duda gives SJRWMD 

an option to repurchase Hooper Farms (552 ha or 1,363 ac) for $4.8 million. 

Option exercised; closing held on March 28, 1990 

1989 SJRWMD signs a consent order with ZDWCD to reduce nutrient loading. 

Consent order is challenged. SJRWMD issues a Management and Storage of 

Surface Waters (MSSW) permit to Duda to construct a reservoir. SJRWMD 

issues a consumptive use permit (CUP) to Duda. The SWIM Plan for Lake 

Apopka is approved by FDEP 

1990 A demonstration marsh flow-way constructed to test operation efficiency of 

marsh filtration. A shad harvesting project begun on Lake Denham to test for 

nutrient removal and food chain effects. The Brady/RICO parcel of 80 ha 

(198 ac) is acquired for $83,197 for the marsh flow-way on January 2. The 446-

ha (1,100-ac) Duda/Whittle parcel is acquired 

1991 Testing of portable barriers in near-shore areas of Lake Apopka to disrupt 

wind mixing and stabilize shallow sediments. The ZDWCD consent order 

upheld after challenge; expires 2001. SJRWMD issues CUP to ZDWCD; 

expires December 1993. SJRWMD issues an Agricultural Surface Water 

Management System (SWMS) permit to Zellwin Sand Farm. The Lake 

Apopka Hydrologic Unit Project initiated to reduce nutrient loading to the 

lake from muck farms 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

308 

Year(s) Event

1992 Planting of desirable vegetation in littoral zone areas begun. Duda 

agricultural discharges meet consent order goals. Wilkinson-Cooper Farm 

acquired on May 15, as required for marsh flow-way project, at a cost of 

$669,296.25 from the P2000 trust fund. C.C. Ranch acquired on May 15 for 

marsh flow-way project at a cost of $669,296.25 from the P2000 trust fund. 

SJRWMD issues CUP to Zellwin Sand Land Farm 

1993 SWIM Plan updated. Begin pilot-scale mass harvest of rough fish for nutrient 

removal. SJRWMD issues modified MSSW permit to Duda to operate 

reservoir; supersedes consent order 

1994 Initial external nutrient budget finished, and scientific basis for phosphorus 

(P) load limit completed in draft. Pollutant load limit for P proposed by 

Governing Board (Chapter 40C-61, F.A.C.). SJRWMD signs settlement 

agreement with Duda concerning nutrient limitations. SJRWMD issues CUP 

to Duda; expires 2004. SJRWMD issues modified SWMS permit to Zellwin 

Sand Farm 

1995 SJRWMD proposed rule 40C-61, F.A.C., successfully challenged by ZDWCD. 

Conceptual plan for full-scale marsh flow-way is completed. The 21-ha 

(53-ac) Blunt parcel is acquired on May 29 for $106,000. The 73-ha (181-ac) 

Boyd-Davis parcel adjacent to the flow-way is acquired for $474,128. Several 

small patches of eelgrass observed in lake near north shore 

1996 Legislation sets a P criterion for the lake, gives SJRWMD legal authority to 

set a P discharge limitation, and provides $20 million to acquire farmland. In 

addition, SJRWMD receives $26 million from the USDA Wetland Reserve 

Program. SJRWMD issues CUP to ZDWCD. Orange County estimated to be 

the fourth fastest growing and the sixth most populated county in the state 

1997 Design of full-scale marsh flow-way completed and a contractor hired for 

Phase I construction. The Legislature approves $45 million for muck farm 

purchase. Purchase of 2,128-ha (5,254-ac) Zellwin Farms approved by the 

Governing Board on April 9. Purchase of Duda’s Jem Farm (1,377 ha) final on 

April 10. Purchase of the Grower’s Precooler (7 ha), Crakes and Sons (205 ha), 

and Clarence W. Beall Jr. muck farms (126 ha) approved by the Governing 

Board for $3.96 million, $2.6 million, and $1.3 million, respectively, on 
Appendix B 

St. Johns River Water Management District

309 

Year(s) Event

November 12. SJRWMD renews the Zellwin Sand Farm permit through 

December 1998. Sixty-three patches of eelgrass totaling 1.16 ha (3.95 ac) and 

small areas of musk grass (Chara spp.) and southern naiad mapped in the 

lake. From January 1993 through June 1997, commercial fishermen removed 

5 million pounds of gizzard shad from the lake. Public workshops held to 

discuss P discharge limits 

1998 During 1998, commercial fishermen harvested 1.7 million pounds of gizzard 

shad from the lake. SJRWMD closes on a total of 3,889 ha (9,602 ac) of 

farmlands. Shallow flooding of former farmlands to control vegetation 

begins. In December, several dead pelicans found on the flooded farms. The 

Zellwood/Mount Dora Christmas Bird Count recorded a North American 

inland record of 174 species. An estimated 25,000 to 40,000 migrating 

shorebirds feeding on former farmlands. Drainage begun in ZDWCD Unit II 

in October and Duda’s Jem Farm in November to facilitate soil amendment 

application 

1999 In January, deaths of American white pelicans and other fish-eating birds on 

the former farmlands recognized as excessive, and draining of the farms 

accelerated to completely dry the area. In February, the U.S. Fish and 

Wildlife Service (USFWS) concluded that organochlorine pesticides killed the 

birds, and launched an investigation. SJRWMD and the National Resource 

Conservation Service launched a scientific investigation of the bird mortality. 

This pesticide study involved the collection and analysis of more than 1,300 

water, soil, and wildlife tissue samples, along with a review of original 

remediation efforts. Final farmlands purchased for a total of 5,554 ha (13,713 

ac) within the North Shore Restoration Area. SJRWMD convenes a technical 

advisory group to assist investigation of the cause of the bird deaths. 

Reflooding of the purchased farmlands delayed until the remediation efforts, 

if needed, were completed. Soil amendment applied to 797 ha (1,968 ac) of 

Duda Jem Farm for P control, beginning in March. The site for the 

environmental education center in the Oakland Nature Preserve purchased 

by the city of Oakland in March 

2000 Construction of the marsh flow-way and spreading of soil amendment 

completed. A revised technical memorandum with P loading limit 

recommendation completed. A Notice of Proposed Rule Development was 

published in the Florida Administrative Weekly on December 29. Between mid1995 and December 2000, a P reduction of 34% and improved water clarity 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

310 

Year(s) Event

(30%) was documented. The Lake Apopka Basin Steering Committee for the 

Lake Apopka Basin Planning Initiative, a coordinated regional planning 

effort involving local planning departments, municipalities, Friends of Lake 

Apopka, the East Central Florida Regional Planning Council, and SJRWMD, 

established 

2001 By January 2001, more than 83 patches of submersed aquatic vegetation with 

a combined area of over 2.63 ha (6.5 ac) had been documented in Lake 

Apopka. A bioaccumulation study, including funds contributed by NRCS, 

initiated in February to evaluate risk from pesticide residues through the 

food chain to fish and then to birds. In June, the Lake Apopka water 

elevation reaches a low of 62.82 ft NGVD 29 due to drought. Following a 

public workshop and a contracted review of existing stormwater treatment 

criteria, the proposed P rule revisions published in the Florida Administrative 

Weekly in December 

2002 Following receipt of a Biological Opinion from USFWS, a portion of the Duda 

Jem Farm reflooded, accompanied by extensive monitoring of water 

chemistry, hydrology, and bird use. Lake Apopka reaches a new low of 62.52 

ft NGVD 29 in June due to continued drought. To improve lake access for 

commercial rough fish harvesting, a dock facility is constructed on the 

McDonald Canal. Consultations were initiated with EPA and USFWS to 

begin operation of the flow-way. Remediation of a highly contaminated area 

was initiated at the NSRA. Over 9,000 tons of soil were excavated from a 

2.43-ha (6-ac) site at the former Lust Farm and disposed of off-site. Final rule 

adoption hearing for the P discharge limitation held in December, rule to be 

effective March 7, 2003 
Appendix B 

St. Johns River Water Management District

311 

Sources (partial)

Brezonik, P.L., S.D. Preston, and T.L. Crisman. 1981. Limnological studies on Lake Apopka and 

the Oklawaha chain of lakes—4: Water quality in 1980 and a summary of the four-year 

database. Report ENV-07-81-02. Department of Environmental Engineering, University of 

Florida, Gainesville. 

Burgess, J.E. 1964. Summary report of Lake Apopka. Florida State Board of Health. Jacksonville, 

Fla. 

Cornell University Laboratory of Ornithology and the National Audubon Society Web site. 

2002. Christmas bird count. Available at http://birdsource.tc.cornell.edu. 

[EPA] U.S. Environmental Protection Agency. 1979. Environmental impact statement, Lake 

Apopka restoration project, Lake and Orange counties, Florida. Region 4, Atlanta. 

Florida Department of Pollution Control. 1972. Lake Apopka Restoration Project. Tallahassee, 

Fla. 

Moody, H. 1972. Personal correspondence to L.E. Jerome, Florida Game and Fresh Water Fish 

Commission, Eustis, Fla., February 11, 1972. 

Olsen, L.A., and B.J. French. 1976. Lake Apopka, Florida: A review of the literature, 1953–1976, 

with recommendations for action by the Department of Environmental Regulation. 

Tallahassee, Fla. 

Rice, K.G., and H.F. Percival, eds. 1996. Effects of environmental contaminants on the demographics 

and reproduction of Lake Apopka’s alligators and other taxa. Technical report 53. Fla. Coop. Fish 

and Wildlife Res. Unit, University of Florida, Gainesville. 

Schiffer, D.M. 1994. Quality of water and bottom sediments, and nutrient and dissolved solids loads in 

the Apopka-Beauclair Canal, Lake County, Florida, 1986–90. Water-Resources Investigations 

Report 93-4103. Tallahassee, Fla.: U.S. Geological Survey. 

Schneider, R.F., and J.A. Little. 1969. Characterization of bottom sediments and selected nitrogen and 

phosphorus sources in Lake Apopka, Florida. Report for the U.S. Department of the Interior, 

Federal Water Pollution Control Administration, Southeast Water Laboratory, Technical 

Programs. Athens, Ga. 

Sheffield, C.W. 1962. Report of the water quality of Lake Apopka, Winter Garden, Florida. 

November 1957–June 1959, May and June, 1962. Orange County Health Department. 

Orlando, Fla. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

312 

Sheffield, C.W., and W.H. Kuhrt. 1969. Lake Apopka—Its decline and proposed restoration. In 

Proceedings from Florida’s Environmental Engineering Conference on Water Pollution Control

24(3), Bul. Series 135. University of Florida, Gainesville. 

Shofner, J.H. 1982. History of Apopka and northwest Orange County. Apopka Historical Society. 

Tallahassee, Fla.: Rose Printing Company. 

Stites, D.L., M. Coveney, L. Battoe, E. Lowe, and V. Hoge. 2001 (draft). An external nutrient 

budget for Lake Apopka. Technical Memorandum. St. Johns River Water Management 

District, Palatka, Fla. 

Yates, M.L. 1967. Personal correspondence to B.F. Joyner, WRD, United States Government, 

Washington, D.C., April 7, 1967. 
Appendix C 

St. Johns River Water Management District

313 

APPENDIX C—LAKES INVENTORY

Below are the locations and physical characteristics of the lakes contained within the 

Lake Apopka drainage basin. 

Location Lake Area 

(acres) Lat/Long Section Township Range 

Elevation 

(ft NGVD) Lcon 

Alden 33 28°41'54" 32 20 28 62 4 

 81°32'12" 

Anne 9 28°41'17" 6 21 28 87 4 

 81°32'46" 

Apopka 30,671 28°39'06" 29 21 27 66 3 

 81°39'29" 

Avalon 162 28°30'38" 6 23 27 91 4 

 81°38'37" 

Beulah 15 28°32'06" 36 22 27 107 4 

 81°33'49" 

Big Breedlove 5 28°36'40" 34 21 26 77 4 

 81°42'22" 

Black 244 28°31'39" 34 22 27 95 4 

 81°36'07" 

Blacks 28 28°33'54" 15 22 26 79 4 

 81°42'17" 

Blacks Still 34 28°34'24" 15 22 26 79 4 

 81°42'13" 

Bonnet 3 28°32'17" 29 22 28 125 1 

 81°32'04" 

Bronson 28°40'10" 17 21 28 68 4 

 81°32'20" 

Camp 12 28°36'16" 5 22 26 83 4 

 81°43'34" 

Carter 8 28°38'11" 29 21 28 71 4 

 81°32'22" 

Clarence 21 28°33'56" 16 22 26 79 4 

 81°42'43" 

Clearwater 49 28°40'31" 7 21 28 70 4 

 81°33'05" 

Eva 2 28°41'26" 6 21 28 86 4 

 81°32'45" 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

314 

Fanny 10 28°44'28" 21 20 27 82 4 

 81°37'09" 

Felter 88 28°31'08" 4 23 26 85 4 

 81°43'22" 

Florence 130 28°35'50" 2 22 26 74 4 

 81°40'59" 

Francis 36 28°42'12" 32 20 28 59 4 

 81°32'26" 

Fuller 36 28°39'45" 17 21 28 68 2 

 81°31'47" 

Gem 2 28°40'42" 8 21 28 78 4 

 81°31'37" 

Gizzard 5 28°37'39" 28 21 26 82 4 

 81°42'55" 

Heininger 23 28°40'56" 7 21 28 68 2 

 81°32'55" 

Hiawatha 28°41'02" 5 21 28 72 4 

 North 81°31'43" 

Holts 33 28°41'12" 6 21 28 104 3 

 81°33'24" 

Johns 2,417 28°32'06" 31 22 27 94 1 

 81°37'59" 

Jones 9 28°37'08" 33 21 26 79 4 

 81°42'40" 

King 3 28°44'06" 23 20 27 68 4 

 81°35'21" 

Lily 18 28°32'40" 29 22 28 114 4 

 81°32'05" 

Lost 17 28°31'58" 33 22 26 83 4 

 81°43'07" 

Lower Doe 10 28°40'30" 8 21 28 68 3 

 81°32'17" 

Luntz 16 28°30'38" 2 23 27 104 4 

 81°34'52" 

Maggiore 30 28°44'12" 22 20 27 84 3 

 81°36'21" 

Marden 20 28°37'52" 29 21 28 69 4 

 81°31'45" 

Marion 7 28°41'45" 6 21 28 61 4 

 81°32'38" 
Appendix C 

St. Johns River Water Management District

315 

Marshall 55 28°40'40" 8 21 28 68 3 

 81°31'59" 

Maynard 15 28°38'40" 21 21 28 66 4 

 81°31'27" 

McKay 6 28°41'22" 1 21 27 89 4 

 81°34'17" 

Medicine 11 28°38'26" 20 21 28 71 4 

 81°32'28" 

Meeks 18 28°37'42" 28 21 26 81 4 

 81°42'35" 

Merritt 24 28°38'02" 27 21 26 76 4 

 81°42'17" 

Minore 21 28°44'20" 22 20 27 84 2 

 81°36'03" 

Mud 1 28°42'25" 34 20 27 63 4 

 81°35'50" 

Mud 4 28°40'40" 7 21 28 69 4 

 81°32'48" 

Mud Bottom 1 28°37'04" 33 21 26 79 4 

 81°42'25" 

Opal 6 28°39'20" 16 21 28 83 4 

 81°31'12" 

Peach 8 28°35'01" 8 22 28 148 4 

 81°31'55" 

Pearl 16 28°32'28" 29 22 28 116 4 

 81°31'59'' 

Pearl 6 28°41'26" 5 21 28 61 4 

 81°32'07" 

Pretty 9 28°43'32" 22 20 26 79 4 

 81°42'03' 

Reaves 22 28°31'32'' 36 22 27 105 1 

 81°33'52" 

Roper 36 28°30'12" 11 23 27 102 4 

 81°34'52" 

Rutherford 17 28°38'40" 20 21 28 69 4 

 81°32'05" 

Sawgrass 1 28°36'11" 2 22 26 73 4 

Pond 81°40'27" 

Semmes 25 28°39'20" 17 21 28 66 4 

 81°32'17" 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

316 

Sheppard 19 28°40'56" 7 21 28 68 3 

 81°32'37" 

Standish 50 28°42'02" 31 20 28 64 4 

 81°33'08" 

Swan 2 28°44'02" 22 20 27 76 4 

 81°35'42" 

Teardrop 9 28°36'59" 32 21 26 82 4 

 81°43'48" 

Tilden 59 28°31'10" 3 23 27 94 3 

 81°35'36" 

Upper Doe 15 28°40'42" 8 21 28 68 3 

 81°32'28" 

Witherington 9 28°40'17" 8 21 28 68 3 

 81°32'13" 

Wolfshead 2 28°38'52" 22 21 26 69 1 

 81°42'23" 

Yarbo 14 28°30'30" 3 23 27 94 3 

 81°35'45" 

Note: Lcon = lake connectivity: 1=inflow, 2=outflow, 3=inflow and outflow, 4=landlocked 
Appendix D 

St. Johns River Water Management District

317 

APPENDIX D—LAND USE/LAND COVER CATEGORIES

URBAN OR BUILT-UP

Urban or built-up land consists of areas of intensive use with much of the land covered 

by structures and other impervious surfaces. Included in this category are cities, towns, 

villages, strip developments along highways, and areas such as those occupied by 

shipping centers, industrial and commercial complexes, and institutions that may, in 

some instances, be isolated from urban areas. 

AGRICULTURE

Lands which are cultivated to produce food crops and livestock make up the 

agricultural category. The subcategories of agriculture are as follows: cropland, 

pastureland, orchards, groves (except citrus), vineyards, nurseries, ornamental 

horticulture areas, citrus groves, confined feeding operations, specialty farms, and other 

agriculture. 

RANGELAND

Rangeland contains natural vegetation which is capable of being grazed, such as native 

grasses, grasslike plants, forbs, or shrubs. Generally this land is not fertilized, 

cultivated, or irrigated. 

FOREST

Forest land includes areas that have a tree-crown areal density of 10% or more. Land 

from which trees have been removed to less than 10% crown closure but which have 

not been developed for other uses are also included in this classification. 

WATER

One definition of water bodies, provided by the Bureau of Census, includes all areas 

within the land mass of the United States that are predominantly or persistently water 

covered. This land use classification includes the following: rivers, creeks, canals, and 

other linear water bodies; inland water bodies; commonly termed lakes; and reservoirs 

and any other artificial impoundment areas of water. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

318 

WETLANDS

Wetlands are those areas where the water table is at, near, or above the land surface for 

a significant part of the year. The hydrologic regime is such that aquatic or hydrophytic 

vegetation usually is established. Wetlands are frequently associated with topographic 

lows. Examples of wetlands include marshes, mudflats, emergent vegetative areas, and 

swamps. Shallow water areas with submerged aquatic vegetation are classed as “water” 

and are not included in the wetlands category. Extensive parts of some river floodplains 

qualify as wetlands. 

BARREN LAND

Barren land has very little or no vegetation and limited potential to support vegetative 

communities. In general, it is an area of bare soil or rock. Barren land categories include 

beaches, exposed rock, and disturbed lands. 
Appendix E 

St. Johns River Water Management District

319 

APPENDIX E—PERMITS

Listing of all Chapter 373, Part IV permits (Chapters 40C-4, 40C-40, 40C-42, 40C-44, and 

40C-400, F.A.C.) for the Lake Apopka Basin 

Explanatory Notes 

This appendix lists permits for nonpoint sources of water pollution or environmental 

resource permits in the SJRWMD permit database, and point source permits for the 

basin in the Florida Department of Environmental Protection (FDEP) permit database as 

of January 2000. 

Environmental resource permits (ERPs) were first issued in 1995. They are a merger of 

the former wetland dredge and fill permit issued by FDEP and the Management and 

Storage of Surface Waters (MSSW) permit issued by the water management districts. 

The purposes of ERPs are to protect wetlands and to ensure that construction takes into 

account flood protection and the protection of waterways from stormwater pollution. 

In the SJRWMD database, permits are indexed by section, township, and range. As the 

Lake Apopka boundaries do not precisely correspond with section, township, and 

range boundaries, there are some permits in this list that lie across or outside the basin 

boundaries. All permits are currently in compliance, and no temporary operating 

permits exist. 

Information provided in this appendix includes application number, owner and 

address, receiving water body, type of use, date the permit was issued, and projected 

acreage. The type of use is generalized to agricultural (AG), commercial (CM), 

industrial (ID), governmental (HGV), recreational park (RA), transportation (TR), and 

residential (RS). 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

320 

Permits for nonpoint source discharges 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-069-0013A A. DUDA & SONS, INC. AG 10/12/82 470 

P.O. Box 257 

Oviedo, FL 32765 

4-069-0028A SWEET BLOSSOM CITRUS CORP. 3/8/83 50 

P.O. Box 129 

Ferndale, FL 34729 

4-069-0055A ALLISON & DUNCAN RS 11/8/83 14 

P.O. Box 460 

Clermont, FL 34711 

4-069-0087A FLORIDA CRUSHED STONE MI 7/10/84 168 

4-069-0087AE 1616 South 14th Street None MI 9/9/86 168 

Leesburg, FL 34749 

4-4-069-0089A JALARMY JOINT VENTURE Johns Lake MI 3/12/85 575 

P.O. Box 158 

Minneola, FL 34755 

4-069-0111A ANDERSON PEAT/ SCOTTS HYPONEX Lake Apopka MI 12/11/84 423 

4-069-0111AF Route 2, Box 138 Lake Apopka MI 423 

Winter Garden, FL 34787 

4-069-0132A ANTHONY HICKS Palatlakaha River, RS 6/11/85 63 

315 E. Robinson Street Lake Louisa 

Orlando, FL 32801 

4-069-0160A MONTVERDE GROVES RS 3/11/86 267 

4-069-0160AM 5000 South Highway 27 Lake Apopka, RS 9/12/89 39 

Leesburg, FL 34748 groundwater 

4-069-0169 ITHACA DEV. CORP. Lake Minnehaha RS 12/9/86 61 

144-10 15TH Road (OFW) 

Whitestone, NY 11357 

4-069-0221A LAKE EQUITY ASSOCIATES, L.P. Lake William RS 6/13/89 113 

4-069-0221AM 2 Fieldstone Drive 6/13/95 88 

Winchester, MA 01890 

4-069-0224A ROBERT A. MANDELL Wetland system to RS 6/13/89 110 

1105 Kensington Park Drive Apopka 

Altamonte Springs, FL 32714 

4-069-0307A DANIS ENVIRONMENTAL MNGT CO. Johns Lake CM 4/11/95 10 

P.O. Box 446 

Killarney, FL 34740 
Appendix E 

St. Johns River Water Management District

321 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-095-0010A HOLDEN DEVELOPMENT 2/9/82 45 

204 South Dillard Street 

Winter Garden, FL 34787 

4-095-0028A PREMIERE ASSOCIATES, INC. Black Lake 11/8/83 89 

4-095-0028AE 230 Sand Lime Road Black Lake and 2/12/84 35 

4-095-0028AE2 Winter Garden, FL 34787 associated wetlands RS 1/14/86 35 

4-095-0028AE3 Black Lake RS 4/6/87 27 

4-095-0034A WILLIAM COGGIN 4/09/84 33 

P.O. Box 1225 

Winter Garden, FL 34787 

4-095-0059A DON GREER 10/9/84 103 

P.O. Box 2249 

Orlando, FL 32802 

4-095-0082A LAKE APOPKA INC. Lulu Creek, RS 2/12/85 122 

P.O. Box 246 Lake Apopka 

Ocoee, FL 34761 

4-095-0105A BOREN DEVELOPMENT CORP. Lake Lily CM 6/11/85 28 

2625 West State Road 434 

Longwood, FL 32779 

4-095-0105AM SCOTTY’S Lake Lily CM 1/9/90 7 

5300 Recker Highway 

Winter Haven, FL 33882-0939 

4-095-0105AM2-ERP

4-095-0109AG CITY OF OCOEE Lake Apopka GV 6/11/85 236 

4-095-0133AC ERROL LAND DEVELOPMENT CO Lakes Pearl, Hiawatha 9/12/85 291 

1355 Errol Parkway and Alden 

Apopka, FL 32703 

4-095-0150A ERROL LAND DEVELOPMENT CO. Lake Alden RS 11/12/85 73 

1355 Errol Parkway 

Apopka, FL 32703 

4-095-0150AM LEXINGTON HOMES Lake Pearl, TR 8/6/90 39 

809 South Orlando Avenue, Suite H Lake Alden 

Winter Park, FL 32789 

4-095-0158A COMMODORE FINANCIAL SERVICES Lake Alden RS 12/10/85 31 

6341 Sunset Drive 

South Miami, FL 33143 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

322 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-095-0179A WALTER DOWMAN Lower Lake Doe RS 11/11/86 10 

642 Interlachen Avenue 

Winter Park, FL 32789 

4-095-0209AC RICHARD AGREE DOT drainage canal to 2/10/87 22 

20300 West 12 Mile Road Black Lake 

Southfield, MI 48076 

4-095-0211AC JAMES GILLS Buchan Pond 3/10/87 278 

1570 U.S. 19 North 

Tarpon Springs, FL 33589 

4-095-0211ACM JAMES P. GILLS Buchan Pond 3/8/88 188 

2418 South Blvd. 

New Port Richey, FL 33552 

4-095-0222A PRIMA VISTA UTILITY CO. None GV 5/12/87 37 

4-095-0222AM 890 SR 434 North GV 11/5/87 160 

Altamonte Springs, FL 32714 

4-095-0232AGC ORANGE CO. BOARD. OF CO. COMM. None 6/9/87 102 

P.O. Box 1393 

Orlando, FL 32802 

4-095-0233A DOYLE C. JONES Lake Tilden AG 6/9/87 123 

4-095-0233AM2 14201 Tilden Road Lake Tilden AG 12/11/90 67 

Winter Garden, FL 34787 2/12/96 

4-095-0233AM DOYLE L. JONES Lake Tilden AG 11/17/87 24 

Box 44 

Windermere, FL 34786 

4-095-0243AG ORANGE COUNTY PUBLIC UTILITIES Lake Marden GV 9/8/87 700 

4-095-0243AGM 109 East Church Street Lake Marden GV 5/8/95 2 

Orlando, FL 32802 

4-095-0259A RICHARD AGREE DOT drainage canal to CM 2/9/88 14 

20300 West 12 Mile Road Black Lake 

Southfield, MI 48076 

4-095-0308AC BRASHK, LTD Black Lake RES 5/9/89 48 

P.O. Box 2062 

Winter Park, FL 32790 

4-095-0309A A. DUDA AND SONS, INC. Lake Apopka AG 8/8/89 2873 

4-095-0309AM P.O. Box 257, West SR 426 Lake Apopka AG 10/12/93 2873 

Oviedo, FL 32765 

4-095-0318A GREATER CONSTRUCTION CORP. Lake Ola RS 8/8/89 135 

1105 Kensington Park Drive 

Altamonte Springs, FL 32714 
Appendix E 

St. Johns River Water Management District

323 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-095-0320AC ARVIDA-JMB PARTNERS Black Lake RS 8/8/09 230 

120 International Parkway 220 

Heathrow, FL 32746 

4-095-0454A HUBBARD CONSTRUCTION COMPANY On-site, landlocked, MI 2/8/94 120 

1936 Lee Road unnamed basin 

Orlando, FL 32789 

4-095-0563A-ERP VOSS, TEAL, MACCHI, SADLER, ROSS, ET Johns Lake RS 9/8/98 111 

2 South Orange Ave. 

Orlando, FL 32801 

4-095-0571A-ERP HELLER BROTHERS GROVES RS 1/12/99 140 

P.O. Box 770249 

Winter Garden, FL 34777-0249 

4-095-0575AG-ERP ORANGE CO. BOARD OF CO. COMM. GV 766 

4-095-0587AC-ERP

40-069-0009A JOANNE SNIDER RS 10/30/84 45 

345 Wade Park Court 

Davenport, FL 328337 

40-069-0031A RAIDLE; ROYAL&FEIL; LOUIS Unnamed tributary to CM 2/5/86 66 

1416 East Robinson Avenue Lake Apopka 

Orlando, FL 32801 

40-069-0033A MONTVERDE GROVES N/A RS 2/17/86 112 

40-069-0042A AL BESADE Little Johns Lake RS 3/31/87 56 

434 Wildoak Circle 

Longwood, FL 32750 

40-069-0073A GREATER CONSTRUCTION CORP. Groundwater, RS 5/3/89 110 

40-069-0073AM 1105 Kensington Park Drive off-site wetland RS 6/5/90 303 

Altamonte Springs, FL 32714 Lake Apopka 

40-069-0079A JIM DURRANCE Groundwater RS 12/5/89 45 

18018 East Apshawa Road (Land locked basin) 

Clermont, FL 32711 

40-069-0081AM ROBERT W. SMITH Lake Apopka RS 10/22/92 73 

17204 Fosgate Road 

Montverde, FL 34756 

40-069-0102A AMERICAN UNIVERSAL DEVLOP. INC. Johns Lake RS 7/15/91 58 

P.O. Box 268 

Gotha, FL 37434 

40-069-0102AM 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

324 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-069-0116AG LAKE CO. BOARD OF CO. COMM. Lake Apopka GV 3/3/93 5 

315 West Main Street 

Tavares, FL 32778 

40-095-0028A WADE BRADFORD Johns Lake RS 1/5/85 117 

40-069-0161AM-ERP

40-095-0075A THE HARKINS CORPORATION 12/16/84 15 

549 West Lake Mary Blvd, #108 

Lake Mary, FL 32746 

40-095-0079A WINTER GARDEN ASSOCIATES Black Lake CM 3/19/86 10 

40-095-0109A AGREE DEVELOPMENT CO. DOT drainage canal to CM 1/23/87 8 

20300 West 12 Mile Road Black Lake 

Southfield, MI 48076 

40-095-0122A CROWN POINT WOODS INC. Lake Apopka RS 6/16/87 23 

P.O. Box 1547 

Winter Garden, FL 34787 

40-095-0124AG ORANGE CO. BOARD OF CO. COMM. Groundwater RS 7/9/87 10 

40-095-0124AGM P.O. Box 1393 No off-site discharge TR 3/29/88 8 

Orlando, FL 32802 

40-095-0142A CATALINA HOMES, INC. Lakes Marshall, RS 1/4/88 43 

40-095-0142AM 644 Ferguson Drive Marshall Lake and RS 2/14/89 43 

Orlando, FL 32805 

40-095-0155A H. L. BEKEMEYER & P. CHRISTENSEN Lake Apopka RS 4/5/88 94 

40-095-0204A ARVIDA-JMB PARTNERS Black Lake RS 10/11/89 115 

40-095-0204AM 120 International Parkway, 220 Black Lake RS 12/6/89 55 

Heathrow, FL 32746 

40-095-0206A BRASK, LTD. Black Lake RS 11/10/89 48 

P.O. Box 2062 

Winter Park, FL 32791 

40-095-0158A WILLIAM LUTRICK Lake Barton RS 5/19/88 11 

40-095-0158AM P.O. Box 30004 Lake Barton CM 7/19/88 11 

Orlando, FL 32862 

40-095-0399AW-ERP HELLER BROTHERS, INC. Lake Apopka 5/5/95 2 

P.O. Box 770249 

Winter Garden, FL 34777 

40-095-0474A-ERP WINSDALE HOLDING, INC. Lake Clarice RS 6/13/96 76 

2207 Kettle Drive 

Orlando, FL 32835 
Appendix E 

St. Johns River Water Management District

325 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-095-0475AG-ERP CITY OF WINTER GARDEN Lulu Creek 1/4/96 6 

P.O. Box 771005 

Winter Garden, FL 34777 

40-095-0687A-ERP FIRST ORLANDO DEVELOPMENT CO. INC. Lake Tilden RS 12/11/97 43 

201 South Orange Avenue, Suite 890 

Orlando, FL 32801 

6-069-0124A GOURD NECK SPRINGS, INC. Lake Apopka 7/22/92 24. 

P.O. Box 98 

Winter Garden, FL 34787 

6-095-0016A D.E. DUPPENTHALER Lake Apopka RS 6/11/90 21 

120 South Dillard Street 

Winter Garden, FL 34787 

4-069-0224AM GREATER CONSTRUCTION CORP. RS CM R 4/9/91 163 

4-069-0224AM2 1105 Kensington Park Drive Unnamed RS RA C 7/9/90 52 

4-069-0224AM3 Altamonte Springs, FL 32714 Lake Apopka RES 12/13/94 75 

4-069-0272A LAKE SUE PARK INC Johns Lake RS 8/11/92 40 

961 Via Lugano 

Winter Park, FL 32789 

4-069-0274AC JOOST P ZYDERVELD Johns Lake RS 10/12/93 97 

4-069-0274ACM 2269 Lee Road 

Winter Park, FL 32789 

4-069-0276A THE GREATER CONSTRUCTION CORP. Lost Lake RS 1/12/93 102 

4-069-0276AM P.O. Box 3873 Lost Lake RS 8/9/94 118 

Longwood, FL 32791 

4-069-0277A MONTVERDE PROPERTY, LTD. Lake Apopka RS 6/8/93 430 

4-069-0277AE 1311 South Vineland Road RA 430 

4-069-0277AEM Winter Garden, FL 34787 RS RA 430 

4-069-0326A-ERP CLERMONT GROVES, INC. ET AL RES 2/13/96 299 

P.O. Box 770338 RES 

Winter Garden, FL 34777 

4-069-0340A-ERP MAGNOLIA DEVELOPMENT, INC. RS 9/9/97 57 

12543 Magnolia Cove Court 

Clermont, FL 34771 

4-069-0340AM-ERP DAN DECKER RS 3/9/99 0.1 

12543 Magnolia Cove Court 

Clermont, FL 34771 

4-069-0347A-ERP CONDEV ASSOCIATES Lake Apopka CM 2/10/98 121 

2487 Aloma Avenue 

Winter Park, FL 32792 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

326 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-069-0355A-ERP LEVITT HOMES, INC. Land-locked RS 465 119 

7777 Glades Road, Ste. 410 

Boca Raton, FL 33434 

4-069-0356A-ERP CENTEX HOMES INC. RS 11/10/98 175 

151 Southall Lane 

Maitland, FL 32751-7190 

4-069-0359A-ERP ROPER MCALLISTER/6E PRT LTD/ROPER RS CM 6/8/99 223 

P.O. Box 770218 

Winter Garden, FL 34777 

4-069-0363AG- LAKE SUMTER COMM. COLLEGE GV 5/11/99 253 

ERP 9501 U.S. Highway 441 

Leesburg, FL 34788 

4-069-0364AM-ERP JAYMARK BLDRS & DEV. INC. Willow Lake RS 11/9/// 30 

230 Mohawk Road 

Clermont, FL 34711 

4-069-0355AM-ERP DIAMOND PLAYERS CLUB, L.C. Land-locked RA 1/12/99 214 

2700 Sweetwater Country Club Dr. 

Apopka, FL 32712 

4-095-0160A P K PARTNERSHIP & MCCLURE Land locked ID 3/11/86 44 

7620 Lake Underhill Drive depression near 

Orlando, FL 32825 ZDWCD 

4-095-0270A JAMES P GILLS Buchan Pond, RS 4/12/88 36 

2418 South Boulevard Lake Alden 

New Port Richey, FL 33552 

4-095-0270AGM3 ORANGE CO. PUBLIC SCHOOLS Buchan Pond GV 6/8/93 18 

6200 Chancellor Drive 

Orlando, FL 32809 

4-095-0270AM APOPKA LAND DEV CO. Buchan Pond RS TR 6/13/89 45 

2600 Maitland Ctr Parkway, Suite 232 

Maitland, FL 32751 

4-095-0270AM2 U.S. HOME CORP. INC. Lake Alden RS TR 5/11/93 4 

4-095-0270AM4 2600 Maitland Ctr Parkway, Suite 262 Lake Buc RS 11/9/93 4 

4-095-0270AM5 Maitland, FL 32751 RS 1/10/95 23 

4-095-0270AM7 Lake Arden RS 11/10/98 10 

4-095-0270AM7E Lake Alden RS 1/12/99 4 

4-095-0271AC ROGER HAYDON Lake Whitney, 5/9/88 455 

13700 58 Street North, #210 Lake Rhea 

Clearwater, FL 32792 
Appendix E 

St. Johns River Water Management District

327 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-095-0284A LAKE WHITNEY LTD Lake Whitney, 10/11/88 310 

13700 58 Street, #210 Lake Rhea 

Clearwater, FL 32792 

4-095-0343A ARIVDA JMB PARTNERS Balce Lake RS 1/9/90 230 

120 International Parkway, Suite 220 

Heathrow, FL 32746 

4-095-0343AMK DVLP. CONSULTS. OF ORLANDO, INC Black Lake 1/14/92 230 

5728 Major Blvd., Ste. 306 

Orlando, FL 32819-7996 

4-095-0345A HYDE PARK COMMUNITIES INC Black Lake RS 2/13/90 55 

4-095-0345AM 5858 Central Avenue, First Floor Lake Apopka RS 8/9/94 13 

St. Petersburg, FL 33707 

4-095-0355A HELLER BROTHERS GROVES Lake Lily ID RS 6/11/90 87 

4-095-0355AM P.O. Box 770249 Lake Lily ID 7/13/93 87 

Winter Garden, FL 34777 

4-095-0357A MAGUIRE ROAD CORPORATION Lake Apopka RS 7/9/90 124 

4-095-0357AM2 2001 Mercy Drive, Suite 104 RS 11/9/93 90 

Orlando, FL 32808 

4-095-0357AM3K TEACHERS INS. AND ANNUITY ASSOC 

730 Third Avenue 

New York, NY 10017 

4-095-0359A LECESSE CORPORATION Lake Lily RS 5/8/90 11 

1412 West Colonial Drive 

Orlando, FL 32804 

4-095-0416A HOMES IN PARTNERSHIP, INC Lake Apopka RS 7/7/92 57 

235 East 5th Street 

Apopka, FL 32703 

4-095-0437A IRRGANG PARTNERSHIP Johns Lake RS 4/13/93 54 

P.O. Box 157 

Killarney, FL 34740 

40-069-0171A WAYNE H GEY Jones Lake, RS 4/12/95 83 

15211 Vinola Place Mud Bottom Lake 

Montverde, FL 34756 

40-069-0196A CLERMONT GROVES INC ET AL RS RA 10/11/95 101 

P.O. Box 770338 

Winter Garden, FL 34777 

40-069- LENNAR LAND PARTNERS Lake Fel RS 3/1/99 11 

0196AM4-ERP 1110 Douglas Ave. Ste. 2040 

Altamonte Springs, FL 32714 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

328 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-069-0201A-ERP BANYAN CONSTRUCTION Jacks Lake, Plum Lake 1/25/96 36 

905-A Jan Mar Court 

Clermont, FL 34711 

40-095-0012A WINTER GARDEN DEV CORP 5/25/84 56 

P.O. Box 1261 

Winter Garden, FL 34787 

40-095-0023AO ORANGE WEST UTILITIES INC 12/6/85 43 

6112 Cheshire Lane 

Orlando, FL 32819 

40-095-0101AG ORANGE COUNTY PUBLIC UTILITIES Lake Marden GV 5/6/87 53 

40-095-0102AM2 

40-069-0281A-ERP GREATER CONSTRUCTION N/A RS 11/13/97 59 

P.O. Box 3873 

Longwood, FL 32791 

40-069-0282A-ERP SOUTH LAKE HOSPITAL, INC. N/A PR 11/18/97 19 

847 Eighth Street 

Clermont, FL 34711 

40-069-0285AM2- JAYMARK BUILDERS Jacks Lake CM 3/30/99 2 

ERP 230 Mohawk Road 

Clermont, FL 34711 

40-069-0302A-ERP HUNTERS LANDING INC. On-site depression RS 7/7/98 79 

222 Capital Court 

Ocoee, FL 34761 

40-069-0304AG-ERP LAKE SUMTER COMM. COLLEGE Landlocked basin GV 7/22/98 10 

9501 U.S. Highway 441 

Leesburg, FL 34288 

40-069-0316A-ERP LENNAR LAND PARTNERS RS 8/10/98 22 

40-069-0317A-ERP 7600 Nob Hill RS 8/10/98 8 

Tamarac, FL 33321 

4-095-0011A REINER, HARRISON, MASCISLI 6/7/83 35 

P.O. Box 217 

Winter Garden, FL 34787 

40-069-0345A-ERP DIAMOND PLAYERS CLUB, LC RA TR 6/8/99 48 

2700 Sweetwater Country 

Apopka, FL 32712 

40-069-0357A-ERP WEST 50 JOINT VENTURE, CONDEV ASSO. Johns Lake 5/17/99 0.4 

2479 Aloma Avenue 

Winter Park, FL 32790 
Appendix E 

St. Johns River Water Management District

329 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-069-0368A-ERP LANDES CONSTRUCTION INC. 11/5/99 

12543 Magnolia Cove Court 

Clermont, FL 34711 

40-069-0374A-ERP PARK SQUARE HOMES 

5401 Kirkman Road, Ste 525 

Orlando, FL 32819 

40-095-0189A LEXINGTON HOMES Lake Todd RS 7/28/89 52 

2367 Coach House Blvd., Suite B (aka Lake Marion) 

Orlando, FL 32806 

40-095-0229A LEXINGTON HOMES Lake Alden via two RS 8/28/90 33 

809 S. Orange Avenue, Suite H retention ponds 

Winter Park, FL 32789 

40-095-0266A 

40-095-0267 QUEST PROPERTIES Black Lake RS 2/27/92 44 

2611 Technology Dr. Ste. 20 

Orlando, FL 32804 

40-095-0309A SUNBREEZE, INC. Lake Cora 4/30/93 38 

520 Magnolia Avenue 

Orlando, FL 32801 

40-095-0309AM2E 

40-095-0384AG ORANGE CO. PUBLIC WORKS DIV. Lake Audie GV 10/11/94 7 

4200 S. John Young Parkway 

Orlando, FL 32839 

40-095-0313A CONFORM INC Fischer Lake RS 8/16/93 70 

435 Douglas Avenue Pearl Lake 

Altamonte Springs, FL 32714 

40-095-0393A THE GALE GROUP/STRASBERG CORP. Lake McKay ID 10/25/94 26 

2105 Park Avenue North 

Winter Park, FL 32789 

40-095-0473A-ERP 

40-095-0040473- Black Lake RS 2/23/99 11 

AKM 

40-095-0489A-ERP RAY AND SYLVIA RICHARDSON Lake Apopka PR 2/23/96 1 

2009 Lauren Beth Avenue 

Ocoee, FL 34761 

40-095-0491A-ERP VILLAGE CONSTRUCTION LTD RS 3/19/96 32 

921 Lexington Parkway 

Apopka, FL 32712 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

330 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-095-0502A-ERP WES BENTON Johns Lake 8/26/96 0 

1212 S Binion Road 

Apopka, FL 32703 

40-095-0539A-ERP 

40-095-0639AM-ERP CHRISTINA SERV. CO. OF FLA., LLC Black Lake CM 6/10/99 5 

203 Pigeon Point Road 

New Castle, DE 

40-095-0714A-ERP PINELOCH MGMT. CORP. Lake Apopka ID 12/17/97 0 

260 West Pineloch Avenue 

Orlando, FL 32806 

40-095-0757AM2- CAMBRIDGE DEVELOPMENT, LTD. Lake Reaves RS 11/25/98 39 

ERP 242 N. Westmonte Drive 

Altamonte Springs, FL 32714 

40-095-0791A-ERP BRITT FARMING Black Lake RS 8/31/98 43 

71 E. Church Street 

Orlando, FL 32801 

40-095-0792AG-ERP CITY OF APOPKA GV 6/2/98 103 

P.O. Box 1229 

Apopka, FL 32704-1229 

40-095-0793A-ERP FIRST ORLANDO DEVELOPMENT CO. Lake Luntz RS 7/22/98 40 

201 S. Orange Ave., Ste 890 

Orlando, FL 32801 

40-095-0795AG-ERP ORANGE CO. BOARD OF CO. COMM. GV 1 

4200 S. John Young Parkway 

Orlando, FL 32839 

40-095-0810A-ERP MI 9/4/98 44 

40-095-0815A-ERP OGDEN ORTHODONTICS N/A CM 1 

516 S. Dillard Street 

Winter Garden, FL 34787 

40-095-0827AG-ERP ORANGE COUNTY Lake Apopka TR RS 11/6/98 9 

4200 S. John Young Parkway 

Orlando, FL 32839-9205 

40-095-0878A-ERP JOHNS LAKE LAND TRUST Johns Lake RS 3/24/99 41 

1135 East Avenue 

Clermont, FL 34711 

40-095-0884AG-ERP CITY OF OCOEE GV 3/5/99 0.03 

150 N. Lakeshore Drive 

Ocoee, FL 34711 
Appendix E 

St. Johns River Water Management District

331 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

40-095-0885-AG-REP ORANGE CO. BOARD OF CO. COMM. Unnamed land-locked GV 3/25/99 0.013

201 S. Rosaling Avenue wetland 

Orlando, FL 32802 

40-095-0889A-ERP GARY SINGER Lake Alden RS 5/27/99 37 

2901 West SR 434, Ste. 141 

Longwood, FL 32779 

40-095-0894A-ERP HELLER BROS. GROVES N/A RA 4/6/99 2 

P.O. Box 77029 

Winter Garden, FL 34777-0249 

40-095-0906A-ERP GREENE, HARRY R. AND JULIA J. N/A MI 7/1/99 53 

P.O. Box 55 

Killarney, FL 34740 

40-095-0906A-ERP KARR, THOMAS, JR., TRUSTEE N/A RA 11/15/99 6 

P.O. Box 135 

Windermere, FL 32786 

40-095-0926A-ERP HESS, MILTON AND VERNA GAIL N/A RS 9/1/99 37 

4413 Down Point Lane 

Windermere, FL 34786 

40-095-0928A-ERP PAVEX CORPORATION N/A 12/27/99 21 

2501 NW 48th St. 

Pompano Beach, FL 33073 

40-095-0935A-ERP BUCKLEY-SHULER PROPERTIES 

4244 International Pkwy #13 

Atlanta, GA 30354 CM 11/29/99 13 

40-095-62480-1 R. S. HOLLAND 11/29/99 25 

P.O. Box 77038 

Winter Garden, FL 34777-0308 

6-095-0017AG CITY OF WINTER GARDEN Lake Apopka RA 9/10/91 7 

P.O. Box 1005 

Winter Garden, FL 34777 

62894 

40-095-0892A-ERP 

62969 

52122 

40-095-0652A-ERP L. WARREN/C. COX/P TERRY/J. & J. KIM RS 12/3/97 60 

71 East Church Street 

Orlando, FL 32801 

40-095-0068A THE HARKINS CORPORATION Lake Alden RS 10/31/85 15 

549 West Lake Mary Blvd, #108 

Lake Mary, FL 32746 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

332 

Application 

No. Owner and Address Receiving Water Body 

Use 

Type 

Date 

Issued 

Projected 

Acreage 

4-095-0330AG ORANGE COUNTY PARKS & RECREATION Lake Apopka RS 10/9/89 52 

118 West Kaley Street 

Orlando, FL 32806 

4-095-0336A SUNSET LAKES LAND DEV CORP Lakes Roper, Lu, and RS 2/13/90 96 

4-095-0336AM-ERP P.O. Box 4429 Luntz and unnamed RS 3/12/96 96 

Winter Park, FL 32793 pond 

40-095-0829A-ERP EFFIE SMITH MI 10/16/98 36 

50 East Myrtle Street 

Apopka, FL 32703 

40-095-0469A-ERP FLORIDA CONF. OF 7TH DAY ADVENTISTS Lake Roper 12/17/96 

655 North Wymore Road, Suite 101 

Winter Park, FL 32789 

40-095-0482A-ERP 

Permits for point source discharges 

Name FDEP Number Expiration Date Compliance 

City of Winter Garden IO0020109-01 5/1/02 Y 

A. Duda & Sons, Inc. FL105635 
Appendix F 

St. Johns River Water Management District

333 

APPENDIX F—GOVERNMENTAL UNITS

Local, regional, state, and federal governmental units that maintain jurisdiction over the 

water body and the land within a one-mile perimeter of Lake Apopka: 

FEDERAL GOVERNMENT

U.S. Environmental Protection Agency, Region 4 

345 Courtland Street, NE 

Atlanta, GA 30365 

(800) 282-0289 

U.S. Army Corps of Engineers, Jacksonville District 

P.O. Box 4970 

Jacksonville, FL 32232 

(904) 232-35940 

Federal Emergency Management Agency, Region IV 

3003 Chamblee-Tucker Road 

Atlanta, GA 30341 

(770) 229-5200 

U.S. Fish and Wildlife Service 

75 Spring Street, SW 

Atlanta, GA 30303 

U.S. Geological Survey 

12201 Sunrise Valley Drive 

Reston, VA 22092 

U.S. Geological Survey 

Sanlando Commerce Center 

224 W. Central Parkway, Suite 1006 

Altamonte Springs, FL 32714 

(407)648-4090 

National Weather Service (NOAA), Southern Region 

819 Taylor Street 

Fort Worth, TX 76102-6614 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

334 

Natural Resources and Conservation Service, State Office 

2614 NW 43rd Avenue 

Gainesville, FL 32607 

(352) 338-9500 

Natural Resources and Conservation Service, Area 3 Office 

613 6th Street, West 

Palmetto, FL 33651 

Consolidated Farm Service Agency, State Office 

4440 NW 25th Place 

Gainesville, FL 32606 

(352) 372-8549 

Consolidated Farm Service Agency, District Office 

Box 7553 

Lakeland, FL 33807 

(813) 533-1084 

STATE GOVERNMENT

(Note: s/c = suncom number) 

Florida Department of Transportation 

605 Suwannee Street 

Tallahassee, FL 32399-0405 

(850) 488-3111; s/c 278-3111 

Florida Department of Environmental Protection 

3900 Commonwealth Boulevard 

Tallahassee, FL 32399-3000 

(850) 488-1554; s/c 278-1554 

Florida Department of Health 

2020 Capitol Circle SE, Bin No. A00 

Tallahassee, FL 32399-1701 

(850) 487-2945 

Florida Division of Emergency Management 

2555 Shumard Oak Boulevard 

Tallahassee, FL 32399-2100 

(850) 413-9900 
Appendix F 

St. Johns River Water Management District

335 

Florida Fish and Wildlife Conservation Commission 

620 South Meridian Street 

Tallahassee, FL 32399-1600 

(850) 488-4976 

University of Florida, IFAS, Dr. Christine Stephens, Dean for Extension 

1038 McCarty Hall 

Gainesville, FL 32611 

(352) 392-1761 

Lake County Cooperative Extension Service 

30205 SR 19 

Tavares, FL 

(407) 343-4101 

Orange County Cooperative Extension Service 

2350 East Michigan Street 

Orlando, FL 

(904) 244-7570 

Florida Department of Community Affairs 

Division of Community Planning 

2555 Shumard Oak Boulevard 

Tallahassee, FL 32399-2100 

(850) 487-4545 

Florida Department of Agriculture and Consumer Affairs 

Plaza Level, The Capitol 

Tallahassee, FL 32399-0810 

(850) 488-3022; s/c 278-3022 

REGIONAL

St. Johns River Water Management District 

P.O. Box 1429 

Palatka, FL 32178-1429 

(386) 329-4500 

East Central Florida Regional Planning Council 

631 North Wymore Road, Suite 100 

Maitland, FL 32751 

(407) 623-1075 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

336 

LOCAL GOVERNMENT

Apopka, City of 

P.O. Drawer 1229 

Apopka, FL 32704 

(407) 889-1700 

Oakland, City of 

P.O. Box 377 

Oakland, FL 34760 

(407) 656-1117 

Winter Garden, City of 

P.O. Box 771005 

Winter Garden, FL 34777 

(407) 656-4111 

Montverde, City of 

P.O. Box 8 

Montverde, FL 34756 

(407) 469-2681 

Lake County Health Department 

421 West Main Street, P.O. Box 1305 

Tavares, FL 32778-1305 

Lake County Soil and Water Conservation District 

12547 Woodlea Road 

Tavares, FL 32778 

(407) 343-2481 

Lake County Board of County Commissioners 

315 West Main Street 

Tavares, FL 32778 

(407) 343-9850 

Lake County Water Authority 

107 North Lake Avenue 

Tavares, FL 32778 

(407) 343-3777 
Appendix F 

St. Johns River Water Management District

337 

Lake County Environmental Management Division 

315 West 9th Street 

Tavares, FL 32778 

(407) 343-2351 

Lake County Department of Growth Management 

Planning and Development Services Division 

315 West Main Street, P.O. Box 7800 

Tavares, FL 32778-7800 

(352) 343-9632 (long-range planning) 

(352) 343-9739 (current planning/zoning) 

Orange County Board of County Commissioners 

P.O. Box 1393 

Orlando, FL 32802-1393 

(407) 236-7350 

Orange County Department of Environmental Protection 

2002 East Michigan Street 

Orlando, FL 32806 

(407) 244-7400 

Orange County Department of Planning 

201 South Rosalind Avenue, 2nd Floor 

P.O. Box 1393 

Orlando, FL 32802-1393 

(407) 836-5600 

Orange County Health Department 

832 West Central Boulevard 

P O. Box 3187 

Orlando, FL 32802-3187 

Orange County Soil and Water Conservation District 

2002 East Michigan Street 

Orlando, FL 32806 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

338 
Appendix G 

St. Johns River Water Management District

339 

APPENDIX G—BIBLIOGRAPHY

Bibliography of past and current studies of Lake Apopka (April 2002). 

ABB. 1998. Phases I and II environmental site assessment reports, Clarence Beall Jr. property. Lake 

Apopka Restoration Agricultural Lands Acquisition Program, Orange County, Fla. 

ABB. 1998. Phases I and II environmental site assessment reports, Stroup Farms. Lake Apopka 

Restoration Agricultural Lands Acquisition Program, Orange County, Fla. 

Adamus, C. 1992. 1991 SWIM priority planning process for the St. Johns River Water Management District, 

Florida. Technical Publication SJ92-2. Palatka, Fla.: St. Johns River Water Management District. 

Addasi, D. 1997. Phosphorus removal by recirculation of Lake Apopka water through marsh area. 

College of Engineering thesis, University of Central Florida, Orlando, Fla. 

Aldridge, F.J., C.L. Schelske, and H.J. Carrick. 1993. Nutrient limitations in a hypereutrophic Florida lake. 

Arch. für Hydrobiologie 127(1):21–37. 

Alexander, P., and H.H. Harper. 1988 (draft). Pilot project for evaluating the feasibility of alum treatment 

for nutrient reductions in muck farm discharges. Professional Engineering Consultants, Tavares, Fla. 

Anderson, W. 1971. Hydrologic considerations in draining Lake Apopka: A preliminary analysis, 1970. OpenFile Report 71004; addendum (letter), 1977. Tallahassee, Fla.: U.S. Geological Survey. 

Ann, Y. 1996. Phosphorus immobilization by chemical amendments in a constructed wetland. Ph.D. 

dissertation, University of Florida, Gainesville. 

Ann, Y., and K.R. Reddy. 1999. Influence of chemical amendments on phosphorus immobilization in soils 

from a constructed wetland. Ecological Engineering 14(1):157–167. 

Apogee Research, Inc. 1996. Lake Apopka economic analysis. Final report for Contract 96G307. Submitted 

to St. Johns River Water Management District, Palatka, Fla. Bethesda, Md. 

Applied Technology and Management, Inc. 1988. A. Duda & Sons, Inc. water budget. Gainesville, Fla. 

———. 1993. Zellwood Drainage and Water Control District water budget, February 1992–January 1993. 

Final report. Gainesville, Fla. 

Arcand-Hoy, L.D., and W.H. Benson. 1998. Fish reproduction: An ecologically relevant indicator of 

endocrine disruption. Environ. Toxicol. Chem. 17(1):49–57. 

Arnold, S.F., M.K. Robinson, A.C. Notides, L.J. Guillette Jr., and J.A. McLachlan. 1996. A yeast estrogen 

screen for examining the relative exposure of cells to natural and xenoestrogens. Environ. Health 

Perspec. 104(5):544–548.
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

340 

Arnold, S.F., P.M. Vonier, B.M. Collins, D.M. Klotz, L.J. Guillette Jr., and J.A. McLachlan. 1997. In vitro

synergistic interaction of alligator and human estrogen receptors with combinations of environmental 

chemicals. Environ. Health Perspec. 105(3):615–618. 

ATRA, Inc. 1997. Environmental risk assessment of a Lake Apopka muck farm wetlands restoration. 

Prepared for St. Johns River Water Management District, Palatka, Fla. 

———. 1998. Comparison of muck farm restoration levels to concentrations in Lake Apopka North Shore 

Restoration Area. Prepared for St. Johns River Water Management District, Palatka, Fla. 

Bachmann, R.W., M.V. Hoyer, and D.E. Canfield Jr. 1997. Can watershed management restore shallow 

Florida lakes? In Proceedings of the Florida Lake Management Society 1997 Annual Meeting, May 7–9, 

1997, Palm Beach Shores, Fla. 

———. 1999. The restoration of Lake Apopka in relation to alternative stable states. Hydrobiologia

394(1-3):219–232. 

———. 2000. Internal heterotrophy following the switch from macrophytes to algae in Lake Apopka, 

Florida. Hydrobiologia 418:217–227. 

———. 2000. The potential for wave disturbance in shallow Florida lakes. Lake Reserv. Man. 16(4)281–291. 

———. 2001. Sediment removal by the Lake Apopka marsh flow-way. Hydrobiologia 448:7–10. 

———. 2001. Evaluation of recent limnological changes at Lake Apopka. Hydrobiologia 448:19–26. 

Bacon, E. 1974. Oakland—The early years. Chuluota, Fla.: Mickler House. 

Baird, R.A., and J.M. Bateman. 1987. A preliminary assessment of phosphorus precipitation-inactivation as a 

restoration technique in Lake Apopka. Spec. Pub. SJ87-SP5. Palatka, Fla.: St. Johns River Water 

Management District. 

Bartholic, J.R., and R.G. Bill. 1977. Freeze study for Lake Apopka vicinity, Phases I and II. (report to FDER and 

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Bartholic, J.R., R.G. Bill, and L.H. Allen Jr. 1978. Measurement of evaporation from lakes and ponds in Florida. 

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———. 1998. Phase I final environmental site assessment remediation plan and Phase III remediation 

plan and remedial action report, for Grower’s Precooler. Certified by HSW Engineering, Inc. Orlando, 

Fla. 

———. 1998. Phase III remediation plan and Phase IV remedial action report, for Long Farms. Certified 

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———. 1999. Remedial action report for Grinnell Farms. Certified by Streamline Environmental. Tampa, 

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———. 1999. Phase III environmental site assessment for Hensel and Rodgers property. Certified by 

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———. 1999. Phase III remediation plan for Potter and Sons, Inc. Certified by Streamline Environmental. 

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———. 1999. Phase III remediation plan for Hickerson Flowers. Certified by Streamline Environmental. 

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———. 2000. Phase III remediation report and Phase IV remedial action report, for World Foliage 

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Beaver Schaberg Associates, Inc. 1995. Algal analysis. Provided for St. Johns River Water Management 

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———. 1995. Trophic structure manipulation, phytoplankton analysis. Contract 91W197. Shaker Heights, 

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Belanger, T.V. 1979. Benthic oxygen demand in selected Florida aquatic systems. Ph.D. dissertation, 

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———. 1981. Benthic oxygen demand in Lake Apopka, Florida. Water Res. 15:267–274. 

———. 1981. Infrared absorption study of humic substances from Lake Apopka sediment, plankton and 

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BEM. 1997. Phase I environ. site assessments for Lust Farms and Lust/Long Precooler. Orlando, Fla. 

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———. 1998. Phase II environmental site assessment, Zellwood Drainage and Water Control District. 

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———. 1999. Phase I environmental site assessment and Phase II final environmental assessment for 

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———. 1999. Phase I environmental site assessment, Wallace Carrots. Orlando, Fla. 

———. 1999. Phase I environmental site assessment, Marsell property. Orlando, Fla. 

———. 1999. Final Phase I, Final Phase II, and Final Phase III environmental site assessments and tank 

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———. 2000. Phase I environmental site assessment, Davison properties. Orlando, Fla. 

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———. 2000. Parcel F waste removal report. Orlando, Fla. 

———. 2000. Phase II environmental site assessment, Marsell property. Orlando, Fla. 

———. 2000. Tank closure assessment report, Zellwin Farms. Orlando, Fla. 

———. 2000. Tank closure assessment report, Duda & Sons, Inc. Orlando, Fla. 

———. 2000. Tank closure assessment report, Lake Apopka lock and dam, Mt. Dora, Fla. Orlando, Fla. 

———. 2000. Final phase III environmental site assessment, parcel B pumphouse. Orlando, Fla. 

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———. 2001. Final phase III environmental site assessment and tank closure assessment reports for parcel 

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———. 2001. Phase I environmental site assessment update, A. Duda & Sons property, Lake Jem, Florida. 

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———. 2002. Phase I environmental site assessment, World Foliage Resources, Inc. Orlando, Fla. 

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———. 1992. Sediments of Newnans Lake: Characteristics and patterns of redistribution following a short-term 

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Guillette, L.J., Jr., J.W. Brock, A.A. Rooney, and A.R. Woodward. 1999. Serum concentrations of various 

environmental contaminants and their relationship to sex steroid concentrations and phallus size in 

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Reddy, K.R., M.M. Fischer, and D. Ivanoff. 1996. Resuspension and diffusive flux of nitrogen and 

phosphorus in a hypereutrophic lake. J. Environ. Qual. 25:363–371. 

———. 1996. Sediment studies in Lake Apopka, Phase I, interim report, October 15, 1995–January 15, 

1996. St. Johns River Water Management District Contract 96W136. Department of Fisheries and 

Aquatic Sciences, University of Florida, Gainesville. 

———. 1997. Sediment and phosphorus deposition in Lake Apopka. Final report. Spec. Pub. SJ97-SP21. Palatka, 

Fla.: St. Johns River Water Management District. 

Reddy, K.R., R.E. Jessup, and P.S.C. Rao. 1988. Nitrogen dynamics in a eutrophic lake sediment. 

Hydrobiologia 159:177–188. 

Reddy, K.R., G. Bao, O.G. Olila, and D.L. Stites. 1998 (draft). Effects of chemical amendments on marsh 

soil chemistry and nutrient flux. Final report submitted to St. Johns River Water Management 

District, Palatka, Fla. 

Reddy, K.R., K.L. Campbell, D.A. Graetz, and K.M. Portier. 1982. Use of biological filters for treating 

agricultural drainage effluents. J. Environ. Qual. 11(4):591–595. 

Reddy, K.R., O.G. Olila, E.M. D’Angelo, D.L. Stites, and M. Coveney. 1996. Nutrient storage and 

movement in the Lake Apopka Marsh, Phase III. Contract 94B271:1996. Final report submitted to St. 

Johns River Water Management District, Palatka, Fla. IFAS, University of Florida, Gainesville. 

Reddy, K.R., P.D. Sacco, D.A. Graetz, K.L. Campbell, and L.R. Sinclair. 1982. Water treatment by aquatic 

ecosystem: Nutrient removal by reservoirs and flooded fields. J. Environ. Manage. 6(3):261–271. 

Reynolds, Smith and Hills Environmental Engineering, Inc. 1968. Summary of Lake Apopka water 

quality project for Lake Apopka muck farmers—Orlando, Fla.: Committee of Muck Farmers. 

Jacksonville, Fla. 

Rhoades, P.B. 1971. First annual report of the Oklawaha comprehensive river basin study. East Central 

Florida Regional Planning Council, Winter Park, Fla. 
Appendix G 

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361 

Rice, K.G., and H.F. Percival, eds. 1996. Effects of environmental contaminants on the demographics and 

reproduction of Lake Apopka’s alligators and other taxa. Technical report 53. Fla. Coop. Fish and Wildlife 

Res. Unit, University of Florida, Gainesville. 

Richey, L.J. 2001. Effects of endocrine-disrupting contaminants on the immune system of hatchling 

American alligators. Ph.D. dissertation, University of Florida, Gainesville. 

Richmond, G.S., and R.G. Grassfield. Zellwood-Orange County Chamber of Commerce. Zellwood, Fla. 

Robinson, H. 1999. Bird report, Zellwood Drainage and Water Control District Unit 1, Unit 2, and the 

Zellwin Sand Farm property at Zellwood, Florida. August 15, 1998–August 14, 1999. Prepared for St. 

Johns River Water Management District, Palatka, Fla. 

———. 2002. Bird usage of Lake Apopka’s North Shore Restoration Area. Zellwood Drainage and Water 

Control District Unit 1, Unit 2, and the Zellwin Sand Farm property at Zellwood, Florida. August 15, 

1999–August 14, 2000. Prepared for St. Johns River Water Management District, Palatka, Fla. 

Ross, Saarinen, Bolton & Wilder Environmental Engineers. 1978. Lake Apopka restoration project: 

Preliminary engineering report. Prepared for the Office of Water Resources Restoration and 

Preservation, Department of Environmental Regulation. Clearwater, Fla. 

———. 1978. Lake Apopka restoration project progress report. Prepared for the Office of Water 

Resources Restoration and Preservation, Department of Environmental Regulation. Clearwater, Fla. 

Rotstein, D.S. 2000. Embryonic mortality in American alligators from Lake Apopka. M.S. thesis, 

University of Florida, Gainesville. 

Rotstein, D.S., T.R. Schoeb, L.M. Davis, T.C. Glenn, B.S. Arnold, and T.S. Gross. 2002. Detection by 

microsatellite analysis of early embryonic mortality in an alligator population in Florida. J. Wildl. Dis. 

38(1):160–165. 

Rouhani, S., and M.R. Wild. 2000. Statistical and geostatistical analysis of NSRA soil/sediment data. Final 

report prepared by NewFields, Inc., for St. Johns River Water Management District, Palatka, Fla., 

Contract SD148AA. Atlanta. 

Schelske, C.L. 1994. Assessing nutrient limitation in a hypereutrophic lake. Lake Reserv. Man. 9(2):116–117. 

———. 1996. Sediment studies in Lake Apopka, Phase I: Interim report: October 15, 1995–January 15, 1996.

St. Johns River Water Management District, Palatka, Fla., Contract 96W136. Department of Fisheries 

and Aquatic Sciences, University of Florida, Gainesville. 

———. 1997. Sediment and phosphorus deposition in Lake Apopka: Final report. Spec. Pub. SJ97-SP21. Palatka, 

Fla.: St. Johns River Water Management District. 

Schelske, C.L., and P. Brezonik. 1992. Can Lake Apopka be restored? Excerpt from Restoration of Aquatic 

Ecosystems: Science, Technology, and Public Policy. Washington, D.C.: National Academy Press. 

Schelske, C.L., and W.F. Kenney. 2001. Model erroneously predicts failure for restoration of Lake 

Apopka, a hypereutrophic, subtropical lake. Hydrobiologia 448:1–5. 
SWIM Plan for Lake Apopka 

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Schelske, C.L., F.J. Aldridge, and H.J. Carrick. 1992. Phytoplankton-nutrient interactions in Lake Apopka. 

Spec. Pub. SJ92-SP9. Palatka, Fla.: St. Johns River Water Management District. 

Schelske, C.L., H.J. Carrick, and F.J. Aldridge. 1995. Can wind-induced resuspension of meroplankton 

affect phytoplankton dynamics. Journal of the North American Benthological Society 14(4):616–630. 

Schelske, C.L., C.M. Donar, and E.F. Stoermer. 1999. A test of paleolimnological proxies for the 

planktonic/benthic ratio of microfossil diatoms in Lake Apopka. In 14th International Diatom 

Symposium. Mayama, Idei, and Koizumi, editors, 387–407. Tokyo, Japan: Koeltz Scientific Books. 

Koenigstein. 

Schelske, C.L., M.F. Coveney, F.J. Aldridge, W.F. Kenney, and J.E. Cable. 1999. Wind or nutrients: Historic 

development of hypereutrophy in Lake Apopka, Florida. T. Berman, ed. In Proceedings from the 

Kinneret Symposium on Limnology and Lake Management 2000+, September 6–11, 1999, Tiberias, Israel. 

———. 2000. Wind or nutrients: Historic development of hypereutrophy in Lake Apopka, Florida. 

Limnology and Lake Management 2000+. Arch. für Hydrobiologie—Spec. Issues Adv. Limnol. 55:543–564. 

Schiffer, D.M. 1994. Quality of water and bottom sediments, and nutrients and dissolved solids loads in the 

Apopka-Beauclair Canal, Lake County, Florida, 1986–90. Water-Resources Investigations Report 93-4103. 

Tallahassee, Fla.: U.S. Geological Survey. 

Schipper, L.A., and K.R. Reddy. 1994. Methane production and emissions from four reclaimed and 

pristine wetlands of southeastern United States. Soil Sci. Soc. Am. J. 584:1270–1275. 

Schneider, R.F., and J.A. Little. 1969. Characterization of bottom sediments and selected nitrogen and phosphorus 

sources in Lake Apopka, Florida. Report for the U.S. Department of the Interior, Federal Water Pollution 

Control Administration, Southeast Water Laboratory, Technical Programs. Athens, Ga. 

Schramm, H.L., Jr., and L.L. Pugh. 1997. Gizzard shad stock estimate for Lake Apopka, Florida, 1995. Miss. 

Coop. Fish and Wildlife Res. Unit. Spec. Pub. SJ97-SP10. Palatka, Fla.: St. Johns River Water 

Management District. 

———. 1997. Gizzard shad stock estimate for Lake Apopka, Florida, 1996. Miss. Coop. Fish and Wildlife Res. 

Unit. Spec. Pub. SJ97-SP11. Palatka, Fla.: St. Johns River Water Management District. 

Segal, D.S., and C.D. Pollman. 1991. Assessment of potential sediment contamination for the restoration of Lake 

Apopka. Spec. Pub. SJ91-SP8. Palatka, Fla.: St. Johns River Water Management District. 

Semenza, J.C., P.E. Tolbert, C.H. Rubin, L.J. Guillette Jr., and R.J. Jackson. 1997. Reproductive toxins and 

alligator abnormalities at Lake Apopka, Florida. Environ. Health Perspec. 105(10)1030–1032. 

Shannon, E.E. 1970. Eutrophication-trophic state relationships in north and central Florida lakes. Ph.D. 

dissertation, University of Florida, Gainesville. 

Sheffield, C.W. 1962. Report of the water quality of Lake Apopka, Winter Garden, Florida. November 

1957–June 1959, May and June, 1962. Orange County Health Department. Orlando, Fla. 
Appendix G 

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363 

———. 1968. Summary report of governor’s Lake Apopka technical committee. 

———. 1969. Agricultural nutrient removal. Presented at Purdue University, May 7, 1969. 

———. 1970. Effects of agricultural drainage waters. Presented at Irrigation and Drainage Specialty 

Conference, November 5, 1970. Miami Beach, Fla. 

Sheffield, C.W., and W.M. Bishop. 1973. Effects of farming-urban drainage on fresh water. Presented at 

Irrigation and Drainage Specialty Conference, April 22–24, 1973, Fort Collins, Colo. 

Sheffield, C.W., and R.T. Kaleel. 1970. Lake Apopka and aquatic weeds. Hyacinth Control Journal 8:45–47. 

Sheffield, C.W., and W.H. Kuhrt. 1970. Lake Apopka—Its decline and proposed restoration. In Proceedings 

from Florida’s Environmental Engineering Conference on Water Pollution Control 24(3), Bul. Series 135. 

University of Florida, Gainesville. 

Sheng, P., and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake Apopka. Vol. II, 

Bathymetric surveys of the northwest section of Lake Apopka, and Vol. III, Lake Apopka 1992 field 

data report. Final reports prepared for St. Johns River Water Management District, Palatka, Fla. 

University of Florida, Gainesville. 

Sheng, P., X. Meng, and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake Apopka. Vol. 

I. Analysis of wind data from Lake Apopka and Orlando Airport. Final report for St. Johns River 

Water Management District, Palatka, Fla. University of Florida, Gainesville. 

Sheng, P., S. Schofield, X. Meng, and K. Ellins. 1994. Assessment of hydrodynamic conditions in Lake 

Apopka. Vol. IV, Dispersion of discharge water from the Apopka-Beauclair Canal into Lake Apopka, 

and Vol. V, A three-dimensional hydrodynamic numerical model of wind-driven circulation in Lake 

Apopka (LAHM3D): Theory, model documentation, user’s manual and model simulation. Final 

reports prepared for St. Johns River Water Management District, Palatka, Fla. University of Florida, 

Gainesville. 

Shireman, J.V., and K.K. Opuszynski. 1992. Ichthyofaunal reconstruction for the management of phytoplankton. 

Spec. Pub. SJ92-SP4. Palatka, Fla.: St. Johns River Water Management District. 

Shofner, J.H. 1982. History of Apopka and northwest Orange County, Florida. Apopka Historical Society. 

Tallahassee, Fla.: Rose Printing Company, Inc. 

Shotts, E.B., L. Martin, A.K. Prestwood, and J.L. Gaines. 1972. Aeromonas-induced deaths among fish and 

reptiles in an eutrophic inland lake. J. Am. Vet. Med. Assoc. 161(6):603–607. 

Shumate, B.C., C.L. Schelske, T.L. Crisman, and W.F. Kenney. 2002. Response of the cladoceran 

community to trophic state change in Lake Apopka, Florida. Journal of Paleolimnology 27:71–77. 

Sinclair, L.R., and R.B. Forbes. 1980. Nutrient removal from drainage waters with systems containing 

aquatic macrophytes. Transactions of the ASAE 23(5):1189–1194. 

[SJRWMD] St. Johns River Water Management District. 1987. Lake Apopka restoration project 

diagnostic/feasibility study. Palatka, Fla. 
SWIM Plan for Lake Apopka 

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———. 1988. Quality assurance project plan for external nutrient loading study. Palatka, Fla. 

———. 1988. Restoration of Lake Apopka: Let’s meet the challenge. Palatka, Fla. 

———. 1989. Lake Apopka: Restoration of a lake, protection of a river. Revised report. Palatka, Fla. 

———. 1993. Lake Apopka S.W.I.M. restoration gizzard shad removal pilot project (video). Palatka, Fla. 

———. 1994. Public hearing, Chapters 40C-1 and 40C-61, F.A.C., Pollutant Load Reduction Goals for Lake 

Apopka. F.O.R. 94-1496. Palatka, Fla. 

———. 1994. Economic impact statement for the proposed amendments to Chapter 40C-61, F.A.C. Works 

of the District Basins. (Lake Apopka Works of the District). SJEIS 94-02. Palatka, Fla. 

———. 1995. The Lake Apopka Marsh Flow-Way Demonstration Project: Interim progress report: March 

1995. Palatka, Fla. 

———. 1998. Lake Apopka restoration agricultural lands acquisition program. Remedial plan scope of 

work. Palatka, Fla. 

———. 1998. Wetland reserve program: Wetland restoration at Lake Apopka, Florida. Palatka, Fla. 

———. 1999. Wetland hydraulic investigation project, Lake Apopka test channel status report. Technical 

memorandum 38. Palatka, Fla. 

———. 2000. District water management plan. Palatka, Fla. 

———. 2000, with 2001 addendum. Land acquisition and management 2000 five-year plan. Palatka, Fla. 

———. 1999. Lake Apopka restoration project: Wildlife impacts and progress toward remediation. A 

report to the Honorable Governor Jeb Bush and the Legislature of the state of Florida. Palatka, Fla. 

———. 2001 (draft). Lake Apopka marsh flow-way plan for initial operation and pesticide monitoring 

and exposure management. Palatka, Fla. 

———. 2001. Landfill closure assessment report for Duda Farms. Palatka, Fla. 

———. 2001. Florida Forever work plan. Palatka, Fla. 

———. 2001. Recreation guide to District lands. Palatka, Fla.: St. Johns River Water Management District. 

———. 2003. Water resource atlas. St. Johns River Water Management District, Palatka, Fla. 

Speer, S.W., and C.H. Cunningham. 2000. Subsurface soil exploration, Lake Apopka restoration, pilot 

dredging program, Orange County, Florida. Ardamann & Associates, Inc., Orlando, Fla. 
Appendix G 

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365 

State of Florida Division of Administrative Hearings. 1995. Final Order. Case 94-6578RP. Zellwood 

Drainage and Water Control District, Petitioner, vs. St. Johns River Water Management District, 

Respondent, and Friends of Lake Apopka, Inc., Intervenor. 

Stenberg, J., and M. Clark. 1998. Monitoring of natural and planted vegetation in the Lake Apopka marsh flowway project, August 1993–March 1995. Spec. Pub. SJ98-SP17. Palatka, Fla.: St. Johns River Water 

Management District. 

Stenberg, J., M. Clark, and R. Conrow. 1998. Development of natural and planted vegetation and wildlife use in 

the Lake Apopka Marsh Flow-Way Demonstration Project: 1990–1994. Spec. Pub. SJ98-SP4. Palatka, Fla.: 

St. Johns River Water Management District. 

Stenberg, J.R., D.L. Day, and G.R. Best. 1991. Development of natural vegetation in the Lake Apopka Marsh 

Flow-Way Demonstration Project: Phase I—Baseline conditions, fall 1990. Spec. Pub. SJ91-SP11. Palatka, 

Fla.: St. Johns River Water Management District. 

Stenberg, J.R., R. Pond, and G.R. Best. 1993. Below-ground biomass and spatial distribution from a 

freshwater marsh in central Florida. In Wetlands: Proceedings of the 13th Annual Conference of the Society 

of Wetland Scientists, New Orleans, La., M.C. Landin, ed., 899–903. 

Stites, D.L. 2000. Benefits of crisis-generated stakeholder involvement: Lake Apopka, Florida. In 

Proceedings of AWRA Annual Conference, 147–148. 

Stites, D.L., M.F. Coveney, L.E. Battoe, and E.F. Lowe. 1994. External nutrient budget and pollution load 

reduction goals for Lake Apopka. Lake Reserv. Manage. 9(2):116–117. 

Stites, D.L., M. Coveney, L. Battoe, E. Lowe, and V. Hoge. 2001 (draft). An external phosphorus budget 

for Lake Apopka. Technical memorandum. St. Johns River Water Management District, Palatka, Fla. 

Stout, I.J., and R. Clerico. 2000. Rodent population study in the North Shore Restoration Area, Part 1 (survey of 

rodents near Lake Apopka). Spec. Pub. SJ2000-SP2. Palatka, Fla.: St. Johns River Water Management 

District. 

Stout, I.J., R.T. Clerico, and K.B. Clanten. 2001. Rodent population study in the North Shore Restoration Area, 

Part II. Technical Publication SJ2001-1. Palatka, Fla.: St. Johns River Water Management District. 

TASK Environmental. 1997. Phase III remedial plan for Zellwin Farms, Lake Apopka, Florida. Tampa, 

Fla. 

———. 1997. Phase IV remedial action report for Duda Farms, Vol. 1, Lake Apopka, Florida. Tampa, Fla. 

———. 1998. Phase IV remedial action report and Interim soil and groundwater assessment report, with 

addendum, for Zellwin Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1998. Phase IV final remedial action report for Duda Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1998. Phase I environmental site assessment of Long Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1998. Phase I environmental site assessment of Clonts Farms, Lake Apopka, Florida. Tampa, Fla. 
SWIM Plan for Lake Apopka 

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———. 1998. Phase I environmental site assessment of Crakes & Sons, Inc., Lake Apopka, Florida. 

Tampa, Fla. 

———. 1999. Phase IV update letters for Duda Farms, Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Hensel and Rodgers property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Hickerson property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments; Phase III remediation plan; and Remedial 

action report, for Progressive Growers, Lake Apopka, Florida. Tampa, Fla. 

———. 1999. Phase I environmental site assessment of Freeman, Baumgardt, and Bledsole property, Lake 

Apopka, Florida. Tampa, Fla. 

———. 1999. Phases I and II environmental site assessments of Teddy Smith property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 1999. Phase I environmental site assessment of World Foliage Resources, Inc. Lake Apopka, 

Florida. Tampa, Fla. 

———. 2000. Phase II environmental site assessment of World Foliage Resources, Inc. Lake Apopka, 

Florida. Tampa, Fla. 

———. 2000. Limited contamination assessment report (LCAR) for Zellwood Drainage and Water 

Control District. Tampa, Fla. 

———. 2000. Phases I and II environmental site assessment of NAPA property, Lake Apopka, Florida. 

Tampa, Fla. 

———. 2000. Phases I and II environmental site assessment of the Strickland property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2000. Phases I and II environmental site assessments of the Bates property, Lake Apopka, Florida. 

Tampa, Fla. 

———. 2000. Soil removal activities at areas D & E, Lake Apopka, Florida. Tampa, Fla. 

———. 2001. Phase I environmental site assessment update of the Strickland property, Lake Apopka, 

Florida. Tampa, Fla. 

———. 2001. Phase I environmental site assessment of the Holt property, Lake Apopka, Florida. Tampa, 

Fla. 

———. 2001. Phase I environmental site assessment of the Shaffer property, Lake Apopka, Florida. 

Tampa, Fla. 
Appendix G 

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———. 2001. Phase I environmental site assessment of the Shortz property, Lake Apopka, Florida. 

Tampa, Fla. 

———. 2001. Phase IV remediation action report for Progressive Growers, Lake Apopka, Florida. Tampa, 

Fla. 

———. 2001. Tank closure assessment report for pump house 3 and pump house 4, Lake Level Canal, 

Lake Apopka, Florida. Tampa, Fla. 

Temsiripong, Y. 1999. Growth and survival rates of wild and repatriated hatchling American alligators 

(Alligator mississippiensis) in central Florida lakes. M.S. thesis, University of Florida, Gainesville. 

Thoman, J.R. 1969. Lake Apopka: A case study of eutrophication. Presented at Biology seminar, Florida 

Technical University, March 6, 1969, Orlando, Fla. 

Thomas, C.C. 1991. Rough fish market survey final report. Spec. Pub. SJ91-SP2. Palatka, Fla.: St. Johns River 

Water Management District. 

Thomas, S., and G. Jackson. 2001. Screening level ecological risk assessment: Tower Chemical site, Clermont, 

Florida. Region 4, Atlanta: U.S. Environmental Protection Agency. 

Tolman, A.J. 1979. Florida’s water resources restoration program. Florida Department of Environmental 

Regulation, Tallahassee, Fla. 

Tuschall, J.R., T.L. Crisman, P.L. Brezonik, and J.N. Allinson. 1979. Limnological studies on Lake Apopka 

and the Oklawaha Chain of Lakes—2: Water quality in 1978. Report ENV-07-79-02. Department of 

Environmental Engineering, University of Florida, Gainesville. 

[USACE Jacksonville] U.S. Army Corps of Engineers. 1993. Master water control manual: Four River Basins 

Project: Ocklawaha River Basin. Jacksonville, Fla. 

[USDA] U.S. Department of Agriculture. 1990. USDA water quality hydrologic unit area proposal for the 

Lake Apopka drainage basin, Orange and Lake County, Florida. Soil Conservation Service. 

Gainesville, Fla. 

———. 2001. Lake Apopka North Shore Restoration Area biological assessment and interim restoration 

plan for Duda property. Natural Resources Conservation Service. Gainesville, Fla. 

[USFWS] U.S. Fish and Wildlife Service. 2002. Biological opinion for the interim restoration plan for the 

Duda sub-east property located at the North Shore Restoration Area of Lake Apopka, Orange 

County, Florida. Jacksonville, Fla. 

van Belle, G., and D.A. Meeter. December 1979. Statistical analysis of aspects of the trophic state of 

selected Florida lakes. Tech. Series Vol. 1, No. 7. Florida Department of Environmental Regulation, 

Tallahassee, Fla. 
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Vonier, P.M., D.A. Crain, J.A. McLachlan, L.J. Guillette Jr., and S.F. Arnold. 1996. Interaction of 

environmental chemicals with the estrogen and progesterone receptors from the oviduct of the 

American alligator. Environ. Health Perspec.. 104(12):1318–1322. 

Vonier, P.M., L.J. Guillette Jr., J.A. McLachlan, and S.F. Arnold. 1997. Identification and characterization 

of estrogen and progesterone receptors from the oviduct of the American alligator (Alligator 

mississippiensis). Biochemical and Biophysical Research Communications 232:308–312. 

Warren, C.S., D.E. Bruderly, M. Angelieri, L.J. Bilello, S. Bucalo, G.W. Finger, R. Hart, S.W. Hinton, J.R. 

Newman, and J.W. Vinzant. 1984. The methane from biomass and waste program. Task 1: Evaluation of 

the Lake Apopka Natural Gas District. Task report prepared by Reynolds, Smith & Hills for Gas 

Research Institute. Contract No. 5080-323-0423(E). Jacksonville, Fla. 

Waters, M.N. 2000. The use of sedimentary algal pigments to infer historical algal communities in Lake 

Apopka, Florida. M.S. thesis, University of Florida, Gainesville. 

Williams, T. 1999. Lessons from Lake Apopka. Audubon 101(4):64–72. 

Willingham, E., and D. Crews. 1999. Sex reversal effects of environmentally relevant xenobiotic 

concentrations on the red-eared slider turtle, a species with temperature-dependent sex 

determination. Gen. Comp. Endocrinol. 113(3):429–435. 

Woods, C. 1973. Agriculture’s pollution solution for Lake Apopka. Sunshine State Agric. Res. Rep.

18(4/5):8–11. 

Woodard, A.R. 1995. DDE, DDD, DDT concentrations in alligator eggs from Lakes Apopka, Griffin, and 

Orange in 1982. Prepared for Lake Apopka Planning Workshop, Jan. 18–19, 1995, Monte Verde, Fla. 

Woodward, A.R., H.F. Percival, M.L. Jennings, and C.T. Moore. 1993. Low clutch viability of American 

alligators on Lake Apopka. Fla. Scientist 56(1):52–62. 
Appendix H 

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APPENDIX H—REPORT SUMMARIES

EXPLANATORY NOTE

This appendix contains, when available, executive summaries or abstracts of reports 

and publications that have been produced by SJRWMD staff or contractors as a result of 

the projects listed in this SWIM Plan. Where no executive summary or abstract was 

included in a report, report conclusions or introductions, if presented, have been 

substituted. For easy cross-reference, the project from which a report was generated is 

listed following the citation. 

PROJECT SUMMARIES

Ann, Y. 1996. Phosphorus immobilization by chemical amendments in a constructed 

wetland. Ph.D. dissertation, University of Florida, Gainesville. 

PROJECTS: North Shore Restoration (LA-3-303-M) and Marsh Flow-Way Restoration 

(LA-3-301-M) 

ABSTRACT

Agricultural lands adjacent to Lake Apopka, Florida, have been converted to a wetland 

with a goal of treating eutrophic lake water. Flooding of the wetland soil has resulted in 

a substantial increase in soluble P flux from soil to the overlying water column. A series 

of laboratory studies were conducted to determine (i) the effectiveness of different 

chemicals in immobilizing soluble P in recently flooded organic soil, (ii) the effect of 

chemical amendment application methods on soluble P release to water column, (iii) 

inorganic P sorption capacity of chemically amended soils and (iv) the P solubility 

change of chemically amended soils as influenced by soil redox potential. 

All amendments (CaCO3, Ca(OH)2, CaMg (CO3)2, Al2(SO4)3nH20, FeCl3, and mixtures of 

CaCO3 with Al2(SO4)3nH20 and FeCl3) enhanced retention of soluble P, and reduction of 

the P flux to the overlying water column was dependent on the amount of chemical 

added. Applications of CaCO3 and Ca(OH)2 at rates of 7 to 15 g kg-1 were effective in 

immobilizing up to 62 and 79% of dissolved reactive P (DRP), respectively. Higher 

CaCO3

 treatments (>15 g kg-1) did not immobilize P any greater than 69%, while 

Ca(OH)2 treatment at 75 g kg-1 decreased up to 100% of DRP. Reduction of DRP was 

proportional to the amount of alum and FeCl3, with up to 80% of DRP immobilized at 

rates of 2 and 12 g kg-1 of FeCl3 and alum, respectively. Relatively higher amounts of 
SWIM Plan for Lake Apopka 

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370 

alum were required to minimize DRP concentration in the floodwater as compared with 

FeCl3 treatments. 

In a comparison of chemical application methods, the results obtained from Column study 

1 (chemicals were incorporated with whole column soil) and Column study 2 (chemical 

amendments were applied to the top 3 cm of the soil column) were similar. Phosphorus 

flux from soil to the overlying water column decreased with the application of 

amendments as follows: FeCl3

 (1-2 g kg-1) > alum (14.5 g kg-1) >Ca(OH)2 (11.3 g kg-1) 

>CaCO3

 (15.3 g kg-1) >Dolomite (126 g kg-1). 

Lake Apopka marsh soil had a high equilibrium phosphorus concentration (EPC0 = 766 

μM P), indicating very high water soluble P. The EPC0

 is defined as the P concentration at 

which the rates of adsorption and desorption are equal. Phosphorus sorption capacities 

(Smax) of chemically amended soils obtained from an incubation study ranged from 13 to 44 

mmol P kg-1 and decreased in the order: alum > Ca(OH)2 > CaCO3 > dolomite > FeCl3 > 

controls, while the capacities of retaining adsorbed P decreased in the order: Ca(OH)2

 > 

CaCO3 > alum > dolomite > FeCl3 controls. The Smax of the alum/FeCl3 amended soils was 

highly correlated with CDB-Al/Fe (• < 0.01), Oxalate-Al/Fe (• < 0.05), and HCl-Al/Fe (• 

< 0.005). The Smax of the soils amended with Ca-based materials was also highly correlated 

with water soluble Ca and 1 M HCl-Ca/Mg (• < 0.005). 

Redox potential (Eh) had significant influence on DRP and water soluble Fe of 

unamended and FeCl3

 amended Lake Apopka marsh soils. Concentrations of the DRP and 

dissolved Fe at –100 mV in porewater were 8 and 10 times higher than those at 350 mV, 

respectively. The concentrations began to change significantly at Eh of about 200 mV, 

indicating that Fe oxidation-reduction processes were occurring. The soils treated with 

alum and CaCO3 were shown to be less sensitive to redox potential changes than control 

and FeCl3

 amended soils. 

Apogee Research, Inc. 1996. Lake Apopka economic analysis. Final report for Contract 

96G307. Submitted to St. Johns River Water Management District, Palatka, Fla. 

Bethesda, Md. 

PROJECT: Socioeconomic Assessment and Methodology (LA-4-209-F) 

EXECUTIVE SUMMARY

This report analyzes the economic effects of converting 14,000 acres of muck farms in 

the Lake Apopka Agricultural Area (LAAA) to recreational uses and thereby reducing 
Appendix H 

St. Johns River Water Management District

371 

phosphorus loadings to the lake. Three separate analyses were conducted on behalf of 

the St. Johns River Water Management District: 

• Potential economic losses and other effects associated with a proposed purchase and 

retirement of 14,000 acres of muck farms in Lake and Orange counties 

• Measures to mitigate employment losses associated with land acquisition 

• Preliminary estimates of recreation benefits associated with restoration of Lake 

Apopka 

Important findings included (all dollar figures are in 1994 dollars): 

• Direct loss of $62 million a year in vegetable sales is likely. 

• Reduction in agricultural output could result in 1,160 fewer jobs if mitigation 

measures are not taken. 

• Direct impacts could result in $49 million a year less regional output in the absence 

of restoration measures. 

• Property tax impacts likely to be modest. 

• LAAA job losses could be largely offset in agriculture and other sectors within the 

Orlando 

Metropolitan Statistical Area: 

• New fishing, hunting, and nature observation associated with lake and marsh 

restoration could reach $30 million a year in direct and indirect sales by 2021. 

• Lake and marsh restoration could generate 588 jobs directly associated with restoration 

and another 125 jobs in retail, lodging, and other services by 2021. 

• Other effects of restoration not estimated in this study, such as increased land values 

and increased recreation in downstream lakes, could be substantial. 

ATRA, Inc. 1997. Environmental risk assessment of a Lake Apopka muck farm wetlands 

restoration. Prepared for St. Johns River Water Management District, Palatka, Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 

EXECUTIVE SUMMARY

This environmental risk assessment of the Duda Farms property was completed to 

evaluate potential ecological risks and describe how potential risks can be addressed 

through site management strategies. Characterization of the potential risks relating to 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

372 

past land uses at muck farms on Lake Apopka is of importance because one component 

of the current effort to restore the lake ecology involves acquisition of surrounding land 

to re-establish wetlands. Removal of land from agricultural production and the 

reclamation of wetlands around the edge of the lake has two major beneficial effects. 

First, these actions can serve to reduce the loading of nutrients and other agriculturallyrelated chemicals into the lake ecosystem. Second is the return of the lake ecosystem to 

one that is functionally more similar to the original ecology. In converting these 

properties back to wetlands, however, it is necessary to evaluate the potential risks 

relating to the existing chemicals that could be realized by the organisms (ecological 

receptors) that recolonize the site. While the general approach of assessing potential 

risks and describing available management strategies can be used as part of an areawide strategy, the levels of risk and the chemicals of importance are specific to the 

particular properties being converted. This report focuses on the specific chemical 

concentrations and conditions at the Duda property in an effort to characterize the 

associated risks and describe how these risks can be affected by management strategies. 

The risk assessment was carried out using a standard paradigm promoted by the 

USEPA and other regulatory agencies. The basic approach is to use conservative 

assumptions (i.e., over-estimations) of the extent of chemical exposure that could result 

for relevant ecological receptors and to compare this to conservative representations of 

the toxicity of the pertinent chemicals. Where this model determines that exposures are 

insufficient to result in doses considered toxic under the intentionally conservative 

assumptions, it can be concluded with substantial certainty that the potential risks are 

not significant for the chemicals, receptors, and effects considered. Where the model 

suggests that exposures could produce unacceptable theoretical risks, a critical 

evaluation of the assumptions used (weight-of-evidence analysis) and a consideration 

of the available management strategies for precluding unacceptable exposure is used to 

characterize the potential for realizing the predicted risks. 

There was only one receptor/chemical combination where the risk model predicted that 

exposures sufficient to produce significant risks could occur (exposure of piscivorous 

birds to total DDTs). This prediction was based upon conservative assumptions about 

the size and type of fish consumed by a great blue heron receptor and about the body 

burden of DDTs that could have accumulated within these fish. It is unlikely that birds 

would find such large fish available as their primary diet. There are available and 

feasible methods to control hydrologic conditions, promoting lush vegetative growth 

and encouraging high sedimentation rates. Thus exposure in the field can be controlled 

such that significant risks levels will not be reached. To verify the attenuation, methods 

to monitor sedimentation and bioaccumulation can be used. While monitoring is 

prudent to ensure that unacceptable or unexpected impacts do not occur, the reduction 
Appendix H 

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373 

in risks anticipated through removing the site from agricultural production and 

preventing additional releases of the chemicals of concern is clear. 

The overall conclusion of the evaluation of the Duda property is that there are no 

potential risks identified that could not be effectively controlled by the available 

management strategies, using natural attenuation as the contaminant remediationmethod for the farm fields. More intensive remediation methods (e.g., soil removal) 

have already been applied at specific places on the property where handling or 

management of chemicals was a regular occurrence. A complete evaluation of 

remediation alternatives is always necessary prior to recommending a comprehensive 

solution, and this site is no exception. However, the benefits to the larger ecosystem 

projected to accrue from the restoration of this property to wetlands is high, particularly 

in conjunction with the risk reduction associated with the cessation of farming. 

ATRA, Inc. 1998. Comparison of muck farm restoration levels to concentrations in Lake 

Apopka North Shore Restoration Area. Prepared for St. Johns River Water 

Management District, Palatka, Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 

INTRODUCTION

1.1 Area Background—Current and Past Uses 

The muck farms currently being considered for restoration were originally part of the 

lakebed of Lake Apopka. Beginning in the 1940s, the land surrounding the north and 

northeast corner of Lake Apopka was drained and diked and canals were created for 

water management. The properties are currently used for agricultural purposes. 

Due to the introduction of nutrients and other chemicals from sources such as effluent 

from citrus-processing plants and a wastewater plant, as well as large quantities of 

agriculture runoff, Lake Apopka is the most seriously impacted aquatic environment in 

the southern basin of the Oklawaha River catchment (Hand et al. 1996). Lake Apopka 

and the approximately 12,000 acres of agricultural land under consideration for 

restoration are shown in Figure 1. The parcels owned by individual farmers may not be 

adjacent; however, considered together, the parcels represent a contiguous area along 

the shore of Lake Apopka 

The properties, owned by various farmers, have been developed over the years for the 

purpose of agriculture and in some instances horticulture. The following information 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

374 

briefly describes the historical development and production of the agricultural lands 

proposed for restoration. 

The 312-acre property owned by Clarence Beall Jr. was developed for use as a muck 

farm in the 1940s and has been used for cultivating various vegetable crops including 

spinach, collards, and celery. Carrots and corn are currently rotated on the Beall 

property (ABB 1998a). 

Clonts farms property was converted to farming in 1949. The parcel includes 643 acres 

of muck soil and 36 acres of wetlands. The property is currently used for farming and 

management of surface water. Carrots, celery, sweet corn and parsley are the primary 

crops (TASK 1998b). 

Crakes & Sons property consists of three parcels totaling 509 acres on the north shore of 

Lake Apopka. Carrots, corn, and radishes are currently grown. Previously grown crops 

include collard greens, mustard greens, and several types of beans (TASK 1998c). 

Duda Farms, Lake Jem farm property consists of two parcels of land developed since 

the 1940s. Currently, the land and associated structures are used for food processing, 

vegetable cultivation and water management. The property consists of 2,900 acres 

including farmland, 200 acres of uplands, 400 acres of wetlands, and 300 acres of 

sovereign land associated with Lake Apopka (Earth Systems Engineering 1997). 

Long Farms property was developed for agricultural farming between 1942 and 1995. 

The 1,000 acre property is characterized by flat, organic muck soil, with irrigation 

canals, ditches, and dirt roads. The current crops are carrots, radishes, and sweet corn 

(TASK 1998a). 

Lust Farms consists of 1,458 acres of muck farmland, 33 acres of sand and 1 acre of 

potential wetland. The property has been utilized for farming since 1942 and the 

principal crops have been sweet corn, carrots, and radishes (BEM 1997). 

Stroup Farms consists of 414 acres on four parcels. The land is currently used for 

rotating carrot and sweet corn crops throughout the year (ABB 1998b). 

Zellwin Farms began in 1947 on 600 acres of property and has expanded to 5,188 acres 

on two parcels of land. Approximately 1,400 acres are sandy upland and the remainder 

of the site is characterized by flat, organic muck soil, with irrigation canals and dirt 

roads. Crops grown on the site include: corn, carrots, mixed lettuce, radishes, cabbages, 

broccoli, beets, and miscellaneous crops (citrus, watercress, cantaloupe, and various 

herbs) (Golder Associates 1997). 
Appendix H 

St. Johns River Water Management District

375 

Restoration Plans—Future Uses 

The St. Johns River Water Management District (the District), under the authority of the 

Lake Apopka Restoration Land Acquisition Project, intends to purchase agricultural 

lands surrounding the northern corner of Lake Apopka to eliminate a significant source 

of nutrients (e.g., phosphorus) to the lake. This will be accomplished by the conversion 

of agricultural land into wetlands. The conversion will not only reduce phosphorus 

inputs, but also eliminate a source of other agriculture-associated chemicals (e.g., 

pesticides) which have historically entered the Lake Apopka ecosystem. A secondary 

effect of this reclamation will be the expansion of ecologically desirable habitat and a 

recruitment of aquatic species onto the property (ATRA 1997). 

The proposed land to be flooded has been delineated at the 69 feet above mean sea level 

(MSL) contour. Flooding will be controlled by the dike and canal water management 

system already in place on the farms. The flooded farmland will initially remain 

separated from Lake Apopka and properties will be monitored following the initial 

phase of restoration. Long-term monitoring plans will be developed by the District, 

coordinating with the Florida Department of Environmental Protection (FDEP). 

Purpose 

The purpose of this assessment is to evaluate the current surface area-weighted average 

sediment concentrations of chemicals of concern (COC) on the agricultural lands of the 

northern shore of Lake Apopka, and to predict those same levels following remediation. 

During earlier evaluations for the Duda farms property, the District developed bulk 

sediment/soil concentrations to serve as threshold values. The values were referred to 

as site remedial action levels (SRAL). At the time, the SRALs were not risk-based, but 

rather selected to reflect ambient levels found throughout the agricultural areas. Any 

soil sample found to have constituent concentrations above the SRAL was remediated. 

These same SRALs were used for interim remedial decisions at the additional Apopka 

agricultural areas. 

Following removal of soil in areas exceeding the SRALs on Duda Farms, the overall 

surface area-weighted average concentrations of toxaphene and DDX (the sum of the 

concentrations of DDT and its metabolites DDE and DDD) were calculated as part of an 

environmental risk assessment (ERA) (ATRA 1997). Upon review of this analysis and a 

regulatory determination by FDEP that the conditions at Duda Farms were suitable for 

risk management and monitoring strategies as proposed by the District, the surface 

area-weighted residual concentrations for Duda Farms were designated as muck farm 

restoration levels (MFRLs). The goal of this assessment is to compare the surface area-
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

376 

weighted average soil concentrations expected at the proposed Lake Apopka 

restoration area, after similar remediation, to the MFRLs. If the calculated postremediation concentrations are similar or lower than the MFRLs based upon the Duda 

farms ERA, then strategies and monitoring plans being developed to manage risks for 

Duda farms will be anticipated to be applicable and effective for all of the proposed 

restoration lands. 

Approach 

Sites with soil chemical concentrations of DDX and toxaphene exceeding the SRALs will 

be treated as areas to remediate. These were determined to be the chemicals of concern 

for the proposed muck farm restoration (see section 2.2). Kriging, a geostatistical 

weighting process, will be used to calculate surface area-weighted average 

concentrations of constituents remaining in the soil following remediation, to determine 

whether MFRLs have been met. 

Baird, R.A., and J.M. Bateman. 1987. A preliminary assessment of phosphorus precipitationinactivation as a restoration technique in Lake Apopka. Special Publication SJ87-SP5. 

Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Phosphorus Inactivation/Precipitation (LA-4-202-F) 

CONCLUSION

Lake Apopka, by virtue of its high pH and high alkalinity, would make an ideal 

candidate for alum precipitation, from a chemical perspective. But given its size, depth, 

and extent of muck, the prospects for long term success of alum treatment are suspect. 

Proceeding to Phase II may answer the question of whether phosphorus cycling from 

the sediments could be retarded in a lake with an extensive sediment component. It 

would also allow the accurate calculation of costs for a large-scale project. However, it 

would remain uncertain how well the floc layer could withstand extensive mixing in 

the whole 12,150 ha of Lake Apopka. 

Battoe, L.E., M.F. Coveney, E.F. Lowe, and D.L. Stites. 1999. The role of phosphorus 

reduction and export in the restoration of Lake Apopka, Florida. In Phosphorus 

biogeochemistry in subtropical ecosystems. K.R. Reddy, G.A. O’Connor, and C.L. 

Schelske, eds., 511–526. Boca Raton, Fla.: Lewis Publishers. 
Appendix H 

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377 

PROJECT: Implementation of Restoration and Management Techniques (LA-6-802-S) 

ABSTRACT

Lake Apopka is a large (125 km2

), shallow (Z = 1.6 m) lake in central Florida made 

hypereutrophic by 50 years of agricultural stormwater discharges from farms on 80 km2

 of 

drained littoral marshes. The lake is characterized by high nutrient levels, high turbidity 

caused by algae and resuspended sediments, and almost no remaining submersed or 

emergent macrophytic vegetation. Phosphorus loading to Lake Apopka is being reduced 

through the purchase of the riparian farms and restoration to aquatic habitat. Additional 

management activities to accelerate recovery of the lake are creation of a treatment 

wetland to remove nutrients and suspended solids from lake water, removal of gizzard 

shad (Dorosoma cepedianum), and replanting of littoral vegetation. Because of concerns that 

reduction in phosphorus (P) loading will be ineffective in restoration of Lake Apopka, we 

have reexamined the empirical and theoretical basis for P load reduction as a lake 

restoration technique. 

Case studies of control of P loading show that a proportional improvement in lake trophic 

condition often is obtained when a significant reduction in P loading is effected. 

Restoration of hypereutrophic, shallow, turbid lakes requires reduction in P loading to 

lower the stability of phytoplankton dominance and increase the stability of macrophyte 

dominance. Several characteristics of Lake Apopka increase the probability that the lake 

will respond to reduction in P loading form adjacent farms. First, P loading (approx. 0.55 g 

P m-2

 yr-1) to the lake during the last 30 years has been elevated about seven-fold compared 

to prefarming levels, and P loading is dominated by farm discharges. Second, 

biogeochemical processes will dampen internal loading from P-rich sediments after 

external loading is reduced. The majority of P enters the lake as soluble reactive P. 

However, as a result of chemical and biological processes, almost 80% of the P in surficial 

sediments is in Ca-Mg-bound (33%) or organic (46%) forms resistant to rapid biological 

uptake. 

Since summer 1995, trophic indicators (TP, TSS, Chl, Secchi depth) in Lake Apopka have 

improved significantly based on an 11-year data set. These changes are consistent with 

modest reductions in P loading achieved since 1993 through regulatory actions. Recently, 

patches of submersed vegetation (e.g., Vallisneria, Chara) have established naturally at 

more than 20 sites around the lake. 

Battoe, L.E., E.F. Lowe, M.F. Coveney, and D.L. Stites. 1994. Determining restoration 

goals for Lake Apopka. Lake Reserv. Manage. 9(2):54. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

378 

PROJECT: Implementation of Restoration and Management Techniques (LA-6-802-S) 

ABSTRACT

The primary restoration goal for Lake Apopka was set by the Florida Legislature in the 

Lake Apopka Restoration Act of 1985, “to return the lake to class III standard.” To 

achieve this at Lake Apopka, water quality standards must be interpreted in light of the 

primary problem, eutrophication. Nutrient and transparency standards both require 

estimation of the pre-impacted condition of the lake. To obtain the best estimate of the 

pre-impacted water quality, we used several independent methods and found that their 

results consistently predicted total phosphorus (TP) values in narrow range (0.008–0.070 

mg/L) that significantly lower than the current concentration (0.220 mg/L). Mass 

balance modeling, with controllable sources eliminated, resulted in a new equilibrium 

TP concentration in the same range. This range is an appropriate restoration goal for the 

lake. Application of Class III standards to estimated pre-impact TP concentrations can 

be achieved by use of empirical relationships relating depth of macrophytes growth, 

Secchi depth, compensation depth, TP, and total nitrogen. Sensitivity analysis using 

these relationships indicates that the standards cannot be met without reduction in the 

lake concentration of TP to 0.050 mg/L or less. 

Belanger, T.V. 1981. Benthic oxygen demand in Lake Apopka, Florida. Water Research

15:267–274. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

ABSTRACT

The benthic oxygen demand of Lake Apopka, Florida was determined using laboratory 

core uptake and flow through system techniques. The core-uptake for five stations in 

Lake Apopka averaged 67 mg O2 m-2 –h and partitioning experiments indicated that the 

oxygen uptake was primarily biological, with bacterial respiration dominating. No 

significant statistical correlations were found between core oxygen uptake rates and 

TKN levels (r = 0.33), percent volatile solids ( r= 0.49), or macroinvertebrate densities 

(r = 0.59). Sediment oxygen uptake rates (Ds

) were logarithmically related to flow rate in 

the following form Ds

 = -A + B in flow. Flow-through system sediment oxygen uptake 

at each station approached similar maximum uptake rates of 130 mg O2 m-2 at high 

(>200 l h-1) flow rates. Lake Apopka is an extremely shallow, wind mixed system and 

sediment uptake rates are expected to approximate this value during periods of intense 
Appendix H 

St. Johns River Water Management District

379 

wind mixing. The relatively low sediment uptake rates obtained for Lake Apopka, a 

hypereutrophic lake, supports the view that during eutrophication sediment respiration 

is progressively replaced by respiration in the water column. 

Benton, J., D. Douglas, and L. Prevatt. 1991. Oklawaha basin fisheries investigations: 

Study XII. Lake Apopka fisheries studies. Florida Game and Fresh Water Fish 

Commission completion report. Wallop-Breaux project F-30-18. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

Since 1957, the limnetic fish population of Lake Apopka has been found to be 

dominated by gizzard and threadfin shad. The littoral zone was dominated by 

centrarchids, which constituted 46% by number and 43% by weight in blocknet 

samples; however, this habitat covers less than 1% of the lake area. Bluegill was the 

dominant centrarchid in littoral samples, but proportionally few attained harvestable 

size. Black crappie were abundant in both littoral and limnetic samples, and an average 

of 22% were of harvestable size. Black crappie were the preferred species in the creel 

survey, as anglers spent over 46,000 hours of effort (88% of the total) to harvest 44,000 

fish in January through March of 1990. Largemouth bass showed an increase in 

production since 1973–1976 (Holcomb 1977), but the numbers of young remained very 

low when compared to other lakes of the Oklawaha chain. The average electrofishing 

catch rate was poor (0.1 bass/min), and no angler success was documented for 

largemouth bass. The spring 1990 largemouth bass stocking was unsuccessful. Small 

size at stocking, low water levels, and predation by black crappie probably contributed 

to poor survival. 

There have been significant improvements for fish species since the 1973–1976 study, as 

largemouth bass, bluegill, and black crappie in littoral areas increased in number and 

biomass above the estimates of 1973–1976. In the limnetic portions of the lake, there 

were significant increases in the number of harvestable black crappie and in brown 

bullhead biomass. 

Substantial improvements in the aquatic habitat must take place before any appreciable 

reduction in the dominance of shad or improvements in largemouth bass recruitment 

will occur. Increased lake level fluctuation and expansion and/or revegetation of littoral 

habitat would contribute to improvements in the sportfish community. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

380 

Benton, J., D. Douglas, and D. Watson. 1994. Ichthyofaunal studies as part of the trophic 

structure manipulation studies. Final report for Segments I–III. Florida Game and 

Fresh Water Fish Commission, Fisheries Research Laboratory. Special Publication 

SJ94-SP5. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Trophic Structure Manipulation (LA-4-207-F) 

EXECUTIVE SUMMARY

Lakes Denham (257 acres), Apopka (30,319 acres), and Beauclair (1,112 acres) were 

sampled from January 1989 through June 1992 to assess the fish community of each lake 

and evaluate the response of Lake Denham’s fish community to the removal of a large 

percentage of gizzard shad. In January of 1990, the SJRWMD installed a plastic mesh 

barrier to isolate Lake Denham from the other lakes of the Ocklawaha chain. A 

contractor employed by the SJRWMD removed 87,356 pounds of gizzard shad (340 

lbs/acre) in 35 haul seine pulls. This was estimated to be an 82% reduction in the stock 

of gizzard shad that were vulnerable to capture by the haul seine. In May 1991, the 

contractor removed 20,040 lbs of gizzard shad (78 lbs/acre) in 13 haul seine pulls, which 

represented an 88% reduction in the catchable gizzard shad stock. In June 1992, eight 

haul seine pulls removed only 6,887 lbs of gizzard shad (27 lbs/acre), and the effort was 

discontinued. 

In the shallow water zone of Lake Denham, subharvestable fish of three sportfish 

species—largemouth bass (less than 9.5 inches) and bluegill or redear sunfish (less than 

5.5 inches)—showed significantly (P <0.1) increased abundance during 1991–92 (June 

through May) from measurements taken during 1989–90 and 1990–91. Lake Beauclair (a 

control lake) also showed a significant increase during 1991–92 in subharvestable 

bluegill and an increase (though not statistically significant) in subharvestable redear. 

No gizzard shad removal was conducted in Lake Beauclair. The influence of other 

factors that may have caused more juvenile game fish to be produced during this year 

(temperature, rainfall, or changes in nutrient inputs to the lake) was not explored within 

the scope of this report. None of the fish communities of the three lakes showed 

significant increases for harvestable-sized largemouth bass, bluegill, or redear. 

Gizzard shad abundance in Lake Denham was effectively reduced by the use of a haul 

seine. Direct methods for measuring gizzard shad abundance (experimental gill nets 

and 1-acre blocknets) were inconclusive in documenting the decline, but indirect 

evidence (such as the shift in length frequency from larger to smaller fish) confirmed 

data derived from the haul seine catch. The gizzard shad population of Lakes Apopka 

and Beauclair showed no significant changes or trends. 
Appendix H 

St. Johns River Water Management District

381 

It is not possible to attribute the increase in juvenile sportfish in Lake Denham to 

gizzard shad removal at this time. Increased sportfish abundance was observed for 

bluegill and redear sunfish in Lake Beauclair, where gizzard shad were not removed. 

There has also not been any increase observed in harvestable-sized (adult) sportfish in 

Lake Denham. Other factors (habitat type and extent) that may influence the abundance 

of juvenile fish and their subsequent recruitment to harvestable sizes were not 

considered within the scope of this report. This study should be continued for another 

season to determine if the increased abundance of juvenile sportfish produce increased 

numbers of adult fish. 

Benton, J., K. Taylor, C. Adams, and R. Hudson. 1995. Methodology and analysis of the 

gizzard shad population of Lake Apopka in central Florida using sagittal otoliths. 

Fisheries Research Laboratory, Florida Game and Fresh Water Fish Commission. St. 

Johns River Water Management District, Palatka, Fla. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

A procedure to assign ages to gizzard shad through the use of a bony structure (sagittal 

otolith) was developed as a segment of Rough Fish Removal Project requirements 

(SJRWMD Contract 94W1 19). This procedure will allow the gizzard shad population of 

Lake Apopka to be analyzed by age groups (cohorts). That information can be used to 

generate vital data concerning the stock size, growth rates, and biomass of gizzard shad 

available to the commercially fished gill nets in the Lake Apopka Rough Fish Removal 

project. 

We evaluated an age sample of 290 fish collected in spring of 1994 using a team of four 

readers. All readers agreed on age assignments for almost 83% of the fish, and three of 

four readers agreed on ages for 92% of the fish, which indicated that age assignments 

could be made with consistency. These data showed that commercial gill nets caught 

fish of two years of age or more, and that females grew faster than males. Males were 

also shorter-lived than females, few survived beyond two years of age. It is important 

that gizzard shad be vulnerable to gill net capture in two years, before natural mortality 

removes a large proportion of the population. There were relatively few fish older than 

three years of age in the gill net samples (which tended to catch larger fish). We 

estimated total annual mortality to range from 57% to 85% during the first three years 

of life through the use of blocknet data collected in 1990 through 1992, and 1994 gill net 

samples produced an estimate of 58% and 54% for ages two through six. Data to 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

382 

validate the presumed annular markings on the otoliths are needed for reliable 

estimation of population parameters, as well as a determination of age- or size-atmaturity which would have bearing on the sustainability of the gizzard shad removal 

project. 

Best, G.R., and M.T. Brown. 1991. Research manual for phase II: The Lake Apopka 

Marsh Flow-Way Demonstration Project. Prepared for St. Johns River Water 

Management District, Palatka, Fla. Center for Wetlands, University of Florida, 

Gainesville. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

SUMMARY

Objectives of this manual were to provide a description of project objectives and 

detailed methods for meeting those objectives. The manual was dynamic with changes 

implemented after interactive deliberations between the District and the Center for 

Wetlands. 

The program objectives included the development of natural and planted vegetation 

and mechanisms for enhancing marsh establishment and studying seed recruitment, 

dispersal, and storage. Specifically, the scope of work included the following: 

• Assess the development of plant communities within the project area. 

• Document the natural plant community structure, phenology, and biomass. 

• In experimental planting sites, evaluate trends in plant community development as a 

function of time since planting. 

• Compare trends in natural and experimental plant community development. 

• Determine phenology of seed production. 

• Assess seed viability of several planted and naturally occurring marsh plants. 

• Assess role of water in transporting marsh seeds. 

• Determine the role that the seed bank plays in plant community dynamics. 

• Assess the effect of hydroperiod on seed germination. 

Bryant, C.T., and S.F. Shih. 1990. A groundwater flow analysis of Lake Apopka, Florida. 

Final report to St. Johns River Water Management District, Palatka, Fla. IFAS, 

University of Florida, Gainesville. 
Appendix H 

St. Johns River Water Management District

383 

PROJECT: External Nutrient Budget Study (LA-1-101-D) 

ABSTRACT

Determination of the subsurface flow of Lake Apopka, Florida is needed for the 1989 

water budget calculations. Thirteen test sites have been set up along the shore of Lake 

Apopka by the St. Johns River Water Management District. The sites measure the 

various parameters required for subsurface flow and water budget calculations. 

Potentiometric head is measured by a battery of piezometers installed in a line 

perpendicular to the lake shore, with four to seven piezometers at varying depths and 

spacings at each site. The central piezometer at each site is read continuously by a 

telemetry system, as is the lake stage recorder. The remaining piezometers are read 

monthly. Hydraulic conductivity is measured by the auger-hoe method every three 

months at the levee sites, in order to account for compaction and alteration of soil there, 

and once a year at the non-levee sites. The depth to the confining layer for the Lake 

Apopka area was estimated by soil logs taken at each site. 

Piezometric data from three sites were eliminated from consideration in this study due 

to their unsatisfactory locations. The shoreline segment lengths of these sites were split 

up among the sites closest to them to maintain consistent seepage results. 

Subsurface flow calculations were performed in four different ways based on Darcy’s 

law. The Darcy’s law basis was chosen because it was the most applicable technique for 

the situation at Lake Apopka. First, seepage was calculated by site using monthly 

potentiometric head readings from the piezometers at minimum and maximum 

distance from the lake at each site. The seepage was calculated for that day and 

multiplied by the number of days in the month. This was done for every month in 1989. 

Second, the lake was divided into two regions, inflow and outflow. Seepage was then 

calculated monthly, by region, using the average regional measured data. Third, 

regression analysis was used to predict daily values for the monthly-read piezometers 

from the continuously-read central piezometers and lake stage. The predicted values 

were averaged monthly for each piezometer. Seepage was then calculated by site for 

each month. Fourth, seepage was calculated monthly, by region, using the average 

regional values obtained from the regression analysis. 

The main advantage with using regression analysis is that it can provide a model that 

predicts seepage from the continuously-read lake stage and central piezometer 

readings. Calculating seepage by site, using the values obtained from regression 

analysis, yielded a total of 1,532.69 ac-ft of outflow seepage and only 996.30 ac-ft of 

inflow seepage. This led to a net result of 536.39 ac-ft of outflow seepage from Lake 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

384 

Apopka in 1989. Inflow seepage reached a maximum of 170.42 ac-ft in December and 

fell to a minimum of 50.89 ac-ft in October. Outflow seepage reached a maximum of 

179.91 ac-ft in January and fell to a minimum of 59.17 ac-ft in December. 

Bryant, C.T., and S.F. Shih. 1990. Hydraulic conductivity analysis of inflow and outflow 

regions adjacent to Lake Apopka, Florida. In Proceedings of the Soil and Crop Science 

Society of Florida 49:32–36. 

PROJECT: External Nutrient Budget Study (LA-1-101-D) 

ABSTRACT

Determination of the hydraulic conductivity of the regions adjacent to Lake Apopka, 

Florida is needed for calculating the subsurface flow. The hydraulic conductivity 

around the lake was separated by two regions, that is, outflow and inflow regions, 

respectively. A sample-size analysis was also performed to test the accuracy of the 

hydraulic conductivity measurements. Results showed that the hydraulic conductivities 

for outflow and inflow regions were 6.755 ft d-1 and 7.851 ft d-1, respectively. Based on 

the current number of measurements, the accuracy of these hydraulic conductivities can 

only reach a 70% level of statistical confidence for both outflow and inflow regions. In 

general, the accuracy of measurements is expected to reach at least an 80% level of 

confidence in which about 25 and 40 measurements are needed for outflow and inflow 

regions, respectively. In other words, an additional 15 measurements for the outflow 

region and 29 for the inflow region are needed to obtain an 80% level of confidence. 

Carrick, H.J., F.J. Aldridge, and C.L. Schelske. 1993. Wind influences phytoplankton 

biomass and composition in a shallow, productive lake. Limnol. Oceanog. 

38(6):1179–1192. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

ABSTRACT

Factors that regulate phytoplankton dynamics in shallow, productive lakes are poorly 

understood. Water-column phytoplankton chlorophyll (avg 105 μg liter–1) determined on 

39 occasions over a 22-month period in shallow (mean depth, 1.7 m) Lake Apopka, 

Florida, correlated best with average daily windspeed compared with other 

environmental variables. High phytoplankton biomass reflects wind-induced 
Appendix H 

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385 

resuspension of a meroplanktonic algal maximum (MAM) that exists on the aphotic lake 

bottom in a layer ~5 cm thick; this assemblage is dominated by microplankton-sized 

diatoms (>60% of total biomass) that can occur in cellular resting stages. Experiments 

demonstrate that the MAM can grow and photosynthesize at rates similar to surface 

populations when exposed to moderate irradiances. Direct inoculation of this 

meroplanktonic assemblage into surface waters during periods of high wind can account 

for a doubling in surface phytoplankton and diatom biomass as well as an increase in algal 

community size. A conceptual model outlines the influence that resuspension of the MAM 

has on ecosystem structure and function in the lake. 

Carrick, H.J., C.L. Schelske, F.J. Aldridge, and M.F. Coveney. 1993. Assessment of 

phytoplankton waters: Application of dilution bioassays. Can. J. Fish. Aquat. Sci.

50(10):2208–2221. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

INTRODUCTION

There is some question as to which primary factors mediate phytoplankton dynamics in 

tropical and subtropical lakes (Kratzer and Brezonik 1981; Osgood 1982; Canfield et al. 

1989), as little research has been conducted on these systems compared with temperate 

systems (Lewis 1987). The evidence for nutrient limitation in subtropical lakes appears 

circumstantial because few controlled experiments have actually been conducted to test 

this hypothesis (cf. Schelske 1989). Relationships between ambient nutrient concentration 

(i.e., TP and TN) and phytoplankton biomass across a suite of Florida lakes support the 

idea that the phytoplankton biomass in these lakes is nutrient limited (Canfield 1983). 

However, additional work has spawned a debate as to whether phytoplankton abundance 

is under strict nutrient control, given the potential for self-shading at the high levels of 

biomass supported in some of these lakes (e.g., Agusti et al. 1990). 

In this study, we evaluated nitrogen (N) and phosphorus (P) limitation of phytoplankton 

in productive waters utilizing an approach whereby nutrient enrichment bioassays are 

coupled with serial dilution of lake water (Paerl and Bowles 1987). Because dilution 

experiments may be prone to experimental artifacts (e.g., Li 1990; Stockner et al. 1990), the 

critical assumptions of the technique were also evaluated. This approach is potentially 

useful because it can serve as experimental evaluation of current management schemes to 

improve water quality in lakes, such as reduction of nutrient loads (Loehr et al. 1980) or 

removal of particulate material (phytoplankton and associated nutrients) from the water 

column of lakes via artificial wetlands (Lowe et al. 1992). The specific objectives of the 
SWIM Plan for Lake Apopka 

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386 

study were to (1) determine if dilution alters phytoplankton N and P limitation, (2) 

evaluate the effect of particle reduction on phytoplankton growth yields, and (3) compare 

our results with the original technique formulated by Paerl and Bowles (1987). 

Conrow, R., E. Marzolf, M.F. Coveney, E. Lowe. 2001. Proposal for interim management 

of the Lake Apopka North Shore Restoration Area. St. Johns River Water 

Management District, Palatka, Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 

SCOPE OF DOCUMENT

We provide here a proposal for interim management of the North Shore Restoration 

Area. As background we include a brief summary of the environmental conditions in 

Lake Apopka, describe the major components of the restoration program, and 

summarize the progress achieved to date. We describe the recent history of land 

acquisition and the bird mortality event that occurred on the recently purchased 

properties. We summarize the toxicological data for the new properties, and propose 

interim flooding and comprehensive monitoring of a portion of the site. We propose 

additional studies to more precisely quantify site-specific bioaccumulation of 

organochlorines in wildlife. 

Conrow, R., and J. Peterson. 2000. A panel atlas of the major aquatic plants of Lake 

Apopka, Florida, using global positioning and geographic information systems. 

Technical memorandum 37. St. Johns River Water Management District, Palatka, 

Fla. 

PROJECT: Littoral Zone Restoration (LA-2-304-M) 

INTRODUCTION

Lake Apopka is a 12,465 ha (30,800 ac) lake located in Orange and Lake counties, about 

25 km (15 mi) northwest of metropolitan Orlando, Florida. Historically, Lake Apopka 

was the second largest lake in the state. However, in the 1940s the northern third—

mostly sawgrass marsh—was isolated by levees from the remainder of the water body. 

The marsh was drained, and by the end of the decade, farming of row crops had begun 

in the rich peat soil. Agricultural production in the “muck farms” reached 7,290 ha 

(18,000 ac) by 1963 (Huffstutler et al. 1965). Along with the increased nutrient load from 
Appendix H 

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farming runoff, discharges from citrus processing plants and from a sewage treatment 

system likely all combined by March 1947 to help fuel the start of persistent major algal 

blooms. By 1950, much of the rooted aquatic vegetation in the lake had disappeared. 

In the ensuing decades, Lake Apopka changed from a clear water, premier bass-fishing 

lake to a hypereutrophic water body with a trophic state index averaging 82–91. Beginning 

in the late 1980s, the St. Johns River Water Management District (SJRWMD) began 

implementing projects to restore Lake Apopka to meet Class III water quality standards 

(Conrow et al. 1993). As the restoration progresses, one measure of success will be the 

return of aquatic vegetation throughout the lake. Additionally, introduction of aquatic 

vegetation along Lake Apopka’s shoreline has been promoted by SJRWMD through 

contractual, volunteer and staff efforts. 

Clugston (1963) reported the common aquatic and marsh plants growing in Lake Apopka 

during a survey conducted in 1959. Chesnut and Barman (1974) performed a comparative 

survey in 1971 and 1972. Both of those studies provided rough estimates of the abundance 

of aquatic and shoreline vegetation, and their general locations. In order to compare 

current conditions with previous surveys and to establish a baseline for quantifying 

changes in future vegetative coverage, we surveyed the entire lake and delineated existing 

plant cover using a global positioning system (GPS). 

METHODS AND RESULTS

The survey was performed between April and November 1997 using a differential Trimble 

GPS unit. Accuracy for the GPS unit is rated at 1 to 3 meters; however, duplicate field 

measurements of fixed points were within 1 meter or less of each other. All GPS data 

points were collected at 1 second intervals. 

Possible submersed vegetation often was identified first, and photographed, from aerial 

overflights performed several times during the mapping project. These areas were then 

located by boat and the areas mapped. The general mapping technique was to boat, canoe, 

or wade along the edges of the vegetation while recording GPS points using a custommade data dictionary. Data recorded in the data dictionary for each vegetated polygon 

included dominant species and density, secondary species and density, water depth at the 

center of the site, and comments (often used to describe the site location or additional 

species). The number of data points used to map each vegetation feature varied 

depending upon the polygon size, shape, and accessibility which usually was determined 

by water depth or tree line. When the land-facing side of the nearshore vegetation could 

not be physically mapped with the GPS due to poor accessibility, all other sides were 

mapped and the software connected the first and last GPS points logged. 
SWIM Plan for Lake Apopka 

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388 

The collected GPS data were converted to a GIS data layer, or coverage, using Trimble 

Pathfinder OfficeTM Software. In some cases where the GPS software had connected the 

first and final points of a polygon to generate the land-facing side, ESRI ARC/INFO®

and ARCVIEW®

 GIS software were used to redraw the land-facing side to more closely 

follow the shoreline contours. Digital Orthophoto Quadrangle (1995) imagery of the 

lake was displayed in the background of the vegetated polygons to assist in the editing 

process. 

PRODUCT DISPLAY

In order to display the GIS vegetation coverage, a panel atlas was compiled. The first 

cover panel map depicts Lake Apopka overlaid with a numbered grid pattern. The 

vegetation coverage contained in each numbered grid square is shown (at a larger scale) 

in the corresponding numbered panel map. Common names of vegetation are provided 

in each panel and Table 1 provides the corresponding scientific names. Only panels of 

grid squares for which vegetation was found are contained in this compilation. Future 

iterations of this atlas will document the effects of planting efforts and natural 

revegetation as the restoration of Lake Apopka progresses. 
Appendix H 

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389 

Common Name Scientific Name

Bulrush Scirpus spp.

Cattail Typha spp.

Chara (muskgrass) Chara spp.

Duck potato Sagittaria lancifolia 

Eel grass Vallisneria Americana 

Hydrilla Hydrilla verticillata 

Moonvine flower Ipomea alba 

Red maple Acer rubrum 

Spatterdock Nuphar luteum 

Egyptian paspalidium Paspalidium geminatum 

Pickerel weed Pontederia cordata 

Sawgrass Cladium jamaicense 

Torpedograss Panicum repens 

Willow Salix spp.

Yellow water lily Nymphaea mexicana 

Conrow, R., and J. Stenberg. 1994. Survival and competitive abilities of wetland species 

in the Lake Apopka demonstration marsh project. Lake Reserv. Manage. 9(2):65–66. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

ABSTRACT

The Lake Apopka Marsh Demonstration Project, a 525-acre constructed wetland site on 

the NW shore of Lake Apopka, Florida, is a test for a full-scale, 5,000-acre project 

designed to annually filter twice the volume of Lake Apopka through a shallow marsh. 

A program to sample the colonization of vegetation was established to determine the 

ability of small planted “islands” to thrive and withstand encroachment by invasive 

species such as cattail (Typha spp.). To assess development of the naturally occurring 
SWIM Plan for Lake Apopka 

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390 

vegetation, nine transects were monitored semi-annually. Monitoring began shortly 

after initial flooding in October 1990. In 1991, each of three 5-acre blocks were planted in 

monotypic or mixed plots with 11 native wetland species. A series of plots were either 

seeded or mulched with soil from a donor wetland, and other control plots were left 

untreated. The plots were regularly sampled to assess plant community development. 

The total number of species in the transects fell from 64 in the 1990 survey to 38 in 1993. 

Cattail has increased coverage in the marsh. The three 5-acre planted blocks differed 

from each other in the number of species found and the amount of cattail 

encroachment. Changes in water depths, distance from then inflow, and prior land use 

may be some of the influencing factors. Planting success or failure for each particular 

species was similar among the blocks. In the 3 years to date, most planted species 

maintained their community integrity against the invasion of cattail or any other 

species. At each site, planted species have migrated past their original borders. Plots 

containing sawgrass (Cladium jamaicensis) did not survive and were replanted with 

Juncus effuses. Maidencane (Panicum hemitomon) plots had poor survival. Spikerush 

(Eleocharis interstincta), and giant bulrush (Scirpus californicus) were most able to invade 

neighboring sites. 

Continental Shelf Associates, Inc. 1988. Literature review and feasibility analysis report on 

ichthyofaunal reconstruction as a technique for restoring Lake Apopka. Special 

Publication SJ88-SP6. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Ichthyofaunal Reconstruction (LA-4-206-F) 

EXECUTIVE SUMMARY

Lake Apopka is highly eutrophic and in need of sound restoration and management. 

Several restoration options are being considered by the St. Johns River Water 

Management District, including a relatively new approach called biomanipulation. 

Biomanipulation or ichthyofaunal reconstruction involves the removal or introduction 

of fish in order to alter the lake trophic structure and ultimately improve water quality. 

The goals of this project are to review the available literature on biomanipulation, 

compile an annotated bibliography on candidate species and biomanipulation, propose 

candidate fish species for introduction, and design pilot studies to determine the 

applicability of the proposed introduction/manipulation to the Lake Apopka 

environment. 

The literature review revealed that biomanipulation approaches to lake management 

are still largely experimental. The results of most studies have been inconclusive. Most 
Appendix H 

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391 

of the reviewed studies were conducted in temperate lakes where fish and plankton 

communities differ from those in subtropical lakes. Variable conditions, settings, and 

research designs which characterized most studies made projections to the Lake 

Apopka environment difficult at best. These problems highlight the need for 

preliminary studies prior to any attempt at biomanipulation in Lake Apopka. 

To date, fish populations have been manipulated in two basic ways in attempts to 

improve water quality. The first, and most prevalent in the literature, involves removal 

of visual feeding zooplanktivorous fishes, resulting in enhanced populations of 

herbivorous zooplankters, which in turn feed upon unwanted algae and consequently 

improve water quality. The second involves the introduction of a filter-feeding fish to 

graze directly upon unwanted algae. Removal has been achieved by introduction of 

predators or by poisoning and restocking with a higher ratio of predators to 

planktivores. 

Despite limited support in the literature, it appears that control of unwanted algae by 

manipulating filter-feeding fishes may have some merit in subtropical lakes. Filterfeeding fish may suppress algal growth directly by grazing or enhance phytoplankton 

biomass indirectly by suppressing herbivorous zooplankton and by increasing nutrient 

availability. If direct effects of algal grazing are not offset by indirect enhancement 

effects, filter-feeding fish can suppress total phytoplankton biomass. 

In Florida, most eutrophic lakes are numerically dominated by filter-feeding gizzard 

shad. This fact indicates their ineffectiveness at reducing algal biomass through feeding 

activities. In fact, it has been suggested that gizzard shad populations may enhance 

phytoplankton growth, and therefore removal of gizzard shad may result in improved 

water quality. An alternative to gizzard shad removal would be the introduction of 

another filter-feeding fish to consume suspended matter (phytoplankton, zooplankton, 

and detritus). 

We recommended two filter-feeders, silver and bighead carp, as best suited for pilot 

studies. Both species have been used in water quality control programs in culture 

ponds, wastewater treatment, and reservoirs (see Appendix A). This recommendation is 

tempered by the fact that both species are exotic, and the careless release of such 

animals could have unpredictable impacts on the entire Oklawaha system. This is why 

the pilot studies are such an important part of evaluating a proposed introduction. The 

studies were designed to provide direct information on the utility of silver and bighead 

carps as algal control agents, but will contribute salient information on ecological effects 

of the carps on the Lake Apopka environment. 
SWIM Plan for Lake Apopka 

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392 

Pilot studies design includes two sequential phases. Phase I involves in situ studies at 

the mesocosm level. Littoral enclosures are proposed as experimental units within 

which to evaluate the effects of various fish combinations on plankton populations and 

water chemistry. Preliminary studies will be needed to estimate appropriate stocking 

densities and number of replicate treatments needed to statistically resolve pertinent 

water chemistry and plankton questions. In the actual experiment, effects of various 

combinations of fish (bighead and silver carp, and gizzard shad) on water chemistry 

and plankton variables will be evaluated by comparison with fishless control 

enclosures. Weekly monitoring of plankton and chemical variables for the period of one 

year is recommended. If Phase I results prove positive, Phase II, a small lake level 

experiment, should follow. The proposed site for Phase II is Lake Carlton, a small lake 

in the Ocklawaha chain with environmental characteristics similar to Lake Apopka. 

Lake Carlton would be stocked with the appropriate combination of fish, followed by 

weekly monitoring of water chemistry and plankton for one year. 

In summary, as a lake restoration technique, biomanipulation is still experimental. 

Other, more proven restoration options should be considered before biomanipulation is 

attempted. If biomanipulation is chosen as a management strategy, then pilot studies 

should be conducted first to evaluate the likelihood of success. We identified filterfeeding silver and bighead carp as the best candidate species for experimentation. 

However, alternatives should be evaluated prior to the introduction of exotic fishes. 

Coveney, M.F. 1995. The Lake Apopka Marsh Flow-Way Demonstration Project: 

Interim progress report. St. Johns River Water Management District, Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

EXECUTIVE SUMMARY

The Marsh Flow-Way Demonstration Project is a pilot project of the St. Johns River 

Water Management District to examine the capacity of a wetland filter to remove 

suspended sediments and particulate nutrients from Lake Apopka. The project is a 520-

acre field experiment to gain operational experience and test concepts relating to 

nutrient removal, hydraulic behavior, and development of vegetation in a wetland 

system. The demonstration project has answered important questions and clarified 

major design and operational issues for the projected full-scale flow-way. Results from 

the demonstration project have provided the necessary scientific and technical basis to 

proceed with design of the full-scale Marsh Flow-Way Project. 
Appendix H 

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393 

Lake Apopka is a large, shallow, hypertrophic lake in central Florida. Phosphorus 

loading from farms located on drained floodplain marshes has been the primary cause 

of eutrophication. High algal densities and surficial sediments mixed by wind action 

limit the transparency of the lake water and prevent growth of submersed, rooted 

plants. The District has developed a comprehensive restoration plan which will reduce 

external phosphorus loading rates, remove phosphorus from lake water by filtration in 

a marsh flow-way and by harvest of rough fish, improve food-web structure through 

harvest of rough fish, and promote revegetation through increased lake level 

fluctuation, planting, and restoration of wetlands. Removal of phosphorus from Lake 

Apopka in algae and suspended sediments will be accomplished through the full marsh 

flow-way to be constructed in phases on approximately 3,500 acres of floodplain 

farmland. Other benefits of the full-scale flow-way include a reduction in nutrient 

loading to Lake Apopka, a reduction in downstream nutrient loading to the Harris 

Chain, and restoration of wetland habitat. 

The Marsh Flow-Way Demonstration Project has shown that hydraulic functioning of 

the wetland is key to effective nutrient removal. Multiple parallel cells are preferable to 

a single, large treatment area. Large-scale channelization must be avoided to maximize 

the hydraulic residence time distribution. Design of the full-scale project will focus on 

solutions to minimize channelization which may include distributed inlet and outlet 

structures, internal berms, and deep areas to intercept channelized flow. 

Removal rates for phosphorus and suspended matter in the demonstration project 

achieved target levels under realistic areal hydraulic loading conditions when 

channelization was absent. Leaching of soluble phosphorus occurred when the soils 

first were inundated and when soils were dried for consolidation. Flooded fallow 

conditions before construction on the full site should reduce but will not eliminate 

leaching. Methods to deal with leaching include soil amendments and recycling of flood 

waters. Drawdown was a necessary and effective technique to consolidate newly 

deposited sediment in the demonstration project. The increased bulk density of the 

sediment after drawdown confirmed earlier projections that the full-scale marsh flowway site contains sufficient volume for sediment storage. 

Coveney, Michael F. 2000 (draft). Sedimentary phosphorus stores and accumulation 

rates and sedimentation coefficient for phosphorus in Lake Apopka. Prediction of 

steady-state phosphorus concentrations at various phosphorus loading rates. 

Technical memorandum. St. Johns River Water Management District, Palatka, Fla. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

394 

PROJECT: Mathematical Modeling (LA-4-103-D) 

INTRODUCTION

The St. Johns River Water Management District (SJRWMD) set by rule (Section 11.6, 

Applicant’s Handbook. Management and Storage of Surface Waters) a phosphorus 

criterion (target phosphorus concentration in the lake water) for Lake Apopka of 0.055 

mg l-1 total phosphorus (TP). This rule followed an examination of historic conditions in 

Lake Apopka to define goals for restoration of the lake and to derive a target range for 

TP in the lake water (Lowe et al. 1995; Lowe et al. 1999). The next step to define a 

loading limit for phosphorus (P) is to establish the maximum P loading to the lake that 

would achieve the target concentration for TP. This allowable loading was calculated 

with the steady-state formulation of Vollenweider’s 1969 input-output model (Reckhow 

and Chapra 1983) which predicts mean lakewater concentration of TP as a function of P 

loading and other variables. 

The Vollenweider 1969 model requires a value for the net sedimentation coefficient for 

P, which we estimated with two approaches: (1) from the net deposition of P in 

sediments between two sampling occasions in 1968 and 198, and (2) from annual 

phosphorus budgets measured from 1989 through 1996. Monthly P budgets for 1989 

through 1994 also provided data to calculate net sedimentation coefficients for P for 

short periods of time. We used these values, which represented transient conditions, to 

examine variables such as P loading that might affect the net sedimentation coefficient 

in the short-term. 

The specific goals of this memorandum are the following: 

• Derive the long-term net sedimentation coefficient for P in Lake Apopka by 

evaluation of net P deposition from sediment data between 1968 and 1987 and from 

annual phosphorus budgets from 1989 through 1996. 

• Evaluate short-term changes in the phosphorus sedimentation coefficient, especially 

changes resulting from low levels of P loading, from monthly P budgets compiled for 

1989–1994. 

• Predict the loading of P to Lake Apopka from external sources that would result in a 

steady-state concentration of TP in the lake water of 0.055 mg l-1. 
Appendix H 

St. Johns River Water Management District

395 

Coveney, M.F., E.F. Lowe, and L.E. Battoe. 2000. Performance of a recirculating wetland 

filter designed to remove particulate phosphorus for restoration of Lake Apopka 

(Florida, USA). Pages 231–237. In Proceedings of the Seventh International Conference 

on Wetland Systems for Water Pollution Control, November 11–16, 2000, Orlando, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

ABSTRACT

Operation of a 14-km2

 wetland filter for removal of total phosphorus (TP) from lake 

water is part of the restoration program for hypereutrophic Lake Apopka, Florida. This 

system differs from most treatment wetlands because (1) water is recirculated back to 

the lake and (2) the goal is removal of particulate phosphorus (P), the dominant form of 

P in Lake Apopka. The operational plan for the wetland is maximization of the rate 

rather than the efficiency of P removal. The St. Johns River Water Management District 

operated a 2-km2

 pilot-scale wetland to examine the capacity of a wetland system to 

remove suspended sediments and particulate nutrients from Lake Apopka. TP in the 

inflow from Lake Apopka ranged from about 0.12 to 0.23 mg l-1, and hydraulic loading 

rate (HLR) varied from 6.5 to 42 m yr-1. The performance of the pilot-scale wetland 

supported earlier predictions. Mass removal efficiencies for TP varied between about 

30% and 67%. A first-order, area-based model indicated a rate constant for TP removal 

of 55 m yr-1. We compared actual removal of P with model predictions and used 

modeled performance to examine optimal operational conditions. Correspondence 

between observed and modeled outflow TP was not good with constant variable values. 

Monte Carlo techniques used to introduce realistic stochastic variability improved the 

fit. The model was used to project a maximal rate of P removal of about 4 g P m-2

 yr-1 at 

P loading 10–15 g P m-2 yr-1 (HLR 60–90 m yr-1). Data from the pilot wetland indicated 

that actual rates of P removal may prove to be higher. Further operation of the wetland 

at high hydraulic and P loading rates is necessary to verify or modify the application of 

the model. 

Coveney, M.F., E.F. Lowe, and L.E. Battoe. 2001. Nutrient removal from eutrophic lake 

water by wetland filtration. Ecological Engineering. Submitted. 
SWIM Plan for Lake Apopka 

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396 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

ABSTRACT

A 14-km2

 wetland filter is part of the restoration of Lake Apopka, Florida, USA. Lake 

water will be recirculated through the wetland, and the goal is removal of suspended 

solids and particle-bound nutrients, especially total phosphorus (TP). The St. Johns River 

Water Management District operated a 2-km2 pilot-scale wetland for 29 months. Hydraulic 

loading rate (HLR) varied from 6.5–65 m yr-1, total suspended solids (TSS) in the inflow 

varied from 40–180 mg l-1, and TP varied from 0.08–0.38 mg l-1. Mass removal efficiencies 

were 89–99% for TSS, 30–67% for TP, and 30–52% for total nitrogen unless flows were 

channelized. A first-order model indicated rate constants for removal of TSS and TP of 107 

m yr-1 and 63 m yr-1, respectively. TP (3 g m-2) leached from the native organic soils and 

vegetation upon initial flooding. With soil treatment to prevent release of TP and inlet 

pumping to maintain 37 m yr-1 HLR, net TP removal would have exceeded 3 g P m-2 yr-1. 

Design of the full-scale wetland benefited from the pilot project in areas related to nutrient 

retention, hydraulic function, soil treatment to bind TP, and drawdown to consolidate 

new deposits. 

Coveney, M.F., D.L. Stites, L.E. Battoe, and E.F. Lowe. 1993. Nutrient retention in a 

restored wetland used for lakewater filtration. ASLO and SWS annual meeting, 

May 30–June 3, 1993, Edmonton, Alberta, Canada. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

ABSTRACT

A demonstration project at Lake Apopka, Florida, filters hypertrophic lake water 

through a 2.4-km2

 wetland to remove particle-bound nutrients. Water was pumped 

through two wetland cells in series and returned to the lake. Water flow varied from 0.4 

to 1.0 m3

/s, and mean depths ranged from 0.35 to 0.75 m. Hydraulic residence time in 

each cell varied between 3 and 12 d. Net retention of particulate matter was >90% in the 

first cell. Between 30% and 50% of total N was removed in the first cell, with little 

additional change in the second. Because of P leached from organic soils, each cell 

initially had negative P removal. As soil leaching declined, P removal efficiencies 

improved to between 30% and 50%. Leaching declined more rapidly in soils which had 

been fallow and hydrated. Data on forms of N and P and not areal N and P retention in 

the wetlands are presented. 
Appendix H 

St. Johns River Water Management District

397 

Crisman, T.L., and J. Beaver. 1988. Lake Apopka trophic structure. Phase I, final report. 

St. Johns River Water Management District, Palatka, Fla. 

PROJECT: Trophic Structure Manipulation (LA-4-207-F) 

CONCLUSION AND RECOMMENDATIONS

In view of the evidence presented in this report, it seems possible that biomanipulation 

of fish populations in Florida lakes can lead to a significant improvement in water 

quality. This statement, however, must be qualified in that our study was limited to one 

season, was conducted over a short temporal span and a complete analysis of the 

phytoplankton data relative to the zooplankton and chemistry has not been undertaken. 

A similar enclosure experiment performed during another season, preferably with 

replicate productivity data, would provide substantial evidence elucidating the nature 

of the filter-feeder zooplankton-phytoplankton relationship for Florida systems. 

Our experiment does provide evidence that the effects of shad and tilapia on plankton 

community metabolism differed greatly. Although both filter-feeders possess similar 

grazing and digestive mechanisms, tilapia did not suppress the native cladoceran 

assemblage, and in fact enhanced their populations. The presence of shad caused wider 

fluctuations in daily dissolved oxygen concentrations, especially when compared to 

tilapia, which may stress or kill desirable game fish. There are also indications that the 

grazing activities of shad promote mineralization and accelerate phosphorous recycling 

as has been observed in other mesocosms (Crisman and Kennedy 1982; Drenner et al. 

1986a). 

The dramatically elevated primary productivity and community respiration of the shad 

bag, combined with the higher assimilable nutrient levels, suggests that in Florida 

systems which are not as nutrient enriched as Lake Apopka, biomanipulation can be a 

mitigating factor for cultural eutrophication if blue tilapia is allowed to replace gizzard 

shad. 

Since the zooplankton communities of the tilapia treatment contained 2–4 times the 

biomass of herbivorous zooplankton than would be expected in a Florida lake of 

comparable trophy, it is difficult to consider modification of fish populations as a 

restoration technique in subtropical and tropical systems dominated by small-bodied 

cladoceran assemblages if it is assumed that the increased abundance of these 

herbivores will directly reduce phytoplankton standing crops through grazing pressure. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

398 

Crumpton, J.E., and W.F. Godwin. 1997. Rough-fish harvesting in Lake Apopka: Summary 

report 1993–96. Special Publication SJ97-SP23. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

Lake Apopka is a shallow, hypertrophic 12,400-hectare (ha) lake located in Lake and 

Orange counties, and is approximately 24 kilometers (km) northwest of Orlando, 

Florida. Degradation of the lake began with construction of canals to lower the level of 

the lake, alteration of the lake marshes to create “muck farms,” and the loading of 

nutrients to the lake from point and nonpoint sources. The first algal bloom reportedly 

occurred in the lake in 1947. Completion of a water control structure in 1956 on the 

Apopka-Beauclair Canal dampened long-term water-level fluctuations in the lake. Sport 

fishing has declined in the lake since the 1950s and lake water quality has deteriorated 

from nutrient loading to the point that the lake experiences continuous algal blooms. 

The decreased water clarity has eliminated most submerged vegetation and the 

continuous sedimentation of algal cells has resulted in accretion of a flocculent sediment 

layer over one foot thick in most areas of the lake. The lake is currently used primarily 

for the harvest of catfish, and gizzard shad and recreational fishing remains poor. 

The St. Johns River Water Management District (SJRWMD) requested that the Florida 

Game and Fresh Water Fish Commission (GFC) allow the large-scale harvest of rough 

fish from the lake. The fish removal would export nitrogen and phosphorus from the 

lake as well as potentially change the lake food chain. Target fish species were gizzard 

shad, gar, and tilapia. The suggested method of harvest was by commercial gill nets. 

Because largemouth bass and sunshine bass had been stocked in the lake and recent 

creel censuses suggested a potential resurgence of the black crappie stocks, by-catch 

from the rough-fish harvest would be evaluated to determine any potential detrimental 

effects of the harvesting activity to the gamefish stocks in the lake. 

Permits to harvest target fish species by gill net were issued by the GFC. Ten permits 

were issued in 1993, 20 in 1994, 30 in 1995 and 1996, and 21 in 1997. The winter-spring 

fishery usually operated from January through May. The summer-fall fishery was 

established in 1995 for the warm-weather period of the year. For this fishery, a total of 

30 permits to harvest rough fish by commercial gill net was provided to the Organized 

Fishermen of Florida (OFF) for distribution among its members. In addition, other 
Appendix H 

St. Johns River Water Management District

399 

potential harvesting gear (a modified purse/gill net and a modified “pair trawl”) were 

tested in the lake in 1995 and 1996. 

The total catch of gizzard shad from both fisheries ranged from a high of almost 1.7 

million pounds in 1994 to a low of about 636,000 pounds in 1995. The average daily 

catch of gizzard shad ranged from a high of 3,425 pounds/boat/day in 1995 to a low of 

2,201 pounds/boat/day in 1997. The highest annual catch of gar was 12,799 pounds in 

1995. Catches of tilapia were never of significance. 

From January 1993 through June 1997, commercial fishermen harvested a total of about 

5,467,484 gizzard shad weighing about 4,888,813 pounds from Lake Apopka. 

Harvesting removed about 178 fish/acre and exported about 34,322 pounds of 

phosphorus and 102,665 pounds of nitrogen from the lake. A stock assessment 

completed in 1995 indicated the most probable population of harvestable gizzard shad 

prior to the 1995 harvest to be about 3,877,582 fish or about 127 fish/acre. The highest of 

three estimates for the harvestable gizzard-shad stock in 1996 was about 2,073,744 fish 

or about 68 fish/acre. The lowest stock estimate for 1996 was about 726,288 harvestable 

gizzard shad or about 24 fish/acre. The estimated harvest for 1996 was about 1,186,364 

shad or about 39 fish/acre. Even allowing for production and growth of young shad, 

commercial fishermen have apparently harvested a significant portion of the standing 

stock of adult gizzard shad in the lake. A decline in the lake gizzard-shad stock is 

further supported by a decrease in mean weight of harvested shad from 1.3 pounds to 

0.7 pounds per fish between 1993 and 1996. 

A number of unsuccessful attempts were made to market gizzard shad for human 

consumption which included test marketing of gizzards and roe. Most gizzard shad 

harvested from Lake Apopka were marketed as bait for the crayfish industry in 

Louisiana and for the blue-crab fishery in Florida and Louisiana. The economic returns 

to both the commercial fishermen and fish processor were low or non-existent because 

of high harvest costs experienced by the fishermen and high processing, shipping, and 

handling costs experienced by the fish processor. Even when the cost of harvesting and 

marketing was shared by SJRWMD, the economic incentive to remove gizzard shad 

from Lake Apopka was very limited and both commercial fishermen and processors 

will participate in the program only when other fishing opportunities are limited. The 

catch of non-target fish species from observed commercial gill nets was low with 

gizzard shad comprising an average of 98% of the total catch. Black crappie was the 

species taken most often as by-catch with catfish, sunshine bass, redear sunfish, bluegill 

sunfish, largemouth bass, bowfin, and Atlantic needlefish being taken infrequently. The 

total gamefish by-catch from all commercially fished gill nets over the 1993–97 period 

was calculated to be 30,636 fish, or less than one game fish per acre of lake. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

400 

Initial mortality of game fish caught in commercial gill nets during the 5-year period 

was 1,684 fish. The majority of this mortality was black crappie. A total of 443 game fish 

taken in commercial gill nets were placed in “holding pens” and observed for 48 hours 

to determine secondary mortality. High survival of game fish was observed during the 

winter-spring fishery period (84%). Survival of gill-net caught fish in the summer-fall 

fishery period was lower (40%); control fish taken by electrofishing experienced similar 

mortality (50%). Total gamefish mortality from harvesting about 5.5 million gizzard 

shad was estimated to be about 7,218 fish over the 5-year period of the project. 

Modified purse gill nets and trawls were not successful for harvesting gizzard shad in 

Lake Apopka; however, standard gill nets were found to be an appropriate method for 

harvesting target fish species from the lake. Catches were adequate for large-scale fish 

removal and the incidental catch of non-target species was low. The survival of gill-net 

caught-and-released game fish was very high during the winter-spring fishery period. 

Warm weather survival was lower, but results were inconclusive because of similar low 

survival of game fish taken by electrofishing and used as controls. Overall, the impact 

to game fish from harvesting gizzard shad from the lake was insignificant. Harvesting 

appeared to have a substantial impact on the gizzard-shad stock and was responsible 

for significant nutrient removal from the lake. Current market demands for gizzard 

shad from Lake Apopka is low, and attempts to develop new markets for products form 

the fish have not been successful. Because of the weak market position, the harvesting 

of gizzard shad from the lake is not yet self-sustaining. 

Crumpton, J.E. 2000. Experimental gill nets in Lake Apopka. Contract 99W308. Florida 

Fish and Wildlife Conservation Commission. Prepared for St. Johns River Water 

Management District, Palatka, Fla. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

Historically, Lake Apopka covered an area of about 50,000 acres. The lake was 

characterized by extensive marshes in the northern portion, clear water with profuse 

submersed aquatic vegetation, and nationally renowned for its sport fishery. The 

construction of the Apopka-Beauclair Canal in the 1880s marked a beginning of change 

in the lake’s hydrology. With the 1920s came external nutrient loading beginning with 

discharges from sewage treatment plants and citrus processing plants. Marshes on the 

north end of the lake were altered to create muck farms in the 1940s. Increased 

development of the farms resulted in additional nutrient loading to the lake. A 
Appendix H 

St. Johns River Water Management District

401 

hurricane in 1947 uprooted most of the submerged vegetation, and the first algal bloom 

followed shortly thereafter. With the exploitation of the marshes, Lake Apopka is now 

Florida’s fourth largest lake, and since the addition of a dam and lock structure on the 

Apopka-Beauclair Canal in 1952, has functioned as a reservoir. 

The environmental degradation of Lake Apopka has been well documented since the 

early 1960s. The resulting decline in the sport fishery of the lake has also been well 

documented. With that degradation came large increases of gizzard shad (Dorosoma 

cepedianum) biomass in the lake. 

The St. Johns River Water Management District, under the SWIM program, has 

conducted experimental management efforts to correct the problems in Lake Apopka, 

primarily by removing phosphorus and nitrogen from the water by harvesting mass 

quantities of gizzard shad. Under funding provided through contracts with the District, 

the Florida Fish and Wildlife Conservation Commission has conducted assessments of 

the gizzard shad population periodically since 1989. Studies from 1989 through 1992 

provided baseline data prior to the commencement of commercial gizzard shad 

removal activities in 1993. Data collected from 1993 through 2000 have been used to 

assess changes in the gizzard shad population that have resulted from shad removal 

activities. 

Experimental gill nets (randomly set lakewide) were used to assess shifts in catch-perunit-of-effort, size, and weight of gizzard shad. A total of 10 net sets were made during 

each sampling regimen. Samples were collected in January and May. 

Danek, L.J., and M.S. Tomlinson. 1989. Bathymetric analysis of Lake Apopka. Special 

Publication SJ89-SP6. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Bathymetry (LA-4-106-D) 

ABSTRACT

A bathymetric survey consisting of a 347-point, 2,000-ft spaced sampling grid was 

conducted on Lake Apopka in June 1989. The survey was conducted using a Raytheon 

Model DE-719 fathometer and LORAN-C for navigation. The depth readings were 

calibrated, adjusted for lake surface slope, hand contoured, and entered into a GIS 

computer system for subsequent analysis and plotting. The measured lake surface area 

is 1.342 x 109

 ft2 and the volume is 6.453 x 109 ft3 with lake level at 66 ft (MSL) (excluding 

interstitial water in the sediments and flocculent layer). The mean lake depth is 4.81 ft. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

402 

The lake is generally flat with two major erosional trough features: one running 

approximately east-to-west across the center of the lake and the other along the south 

and west shoreline. The maximum depth measured (other than the depth at Apopka 

Springs) was 16.0 ft in the trough along the south shore. 

Error analysis of the results indicated the field survey depth data were adjusted to fit 

the calibration data points with an accuracy of ± 0.25 ft at the 95% confidence level. This 

corresponds to an error of ± 0.335 x 109

 ft3 for the lake volume estimate or about 5%. The 

surface area and the lake volume calculations made from the metric bathymetry chart 

and the English-unit chart agreed within 2.0%. 

Dean, H., and E. Lowe. 1998. The restoration program for Lake Apopka, Florida. Vol. 5, 

313–316. In Proceedings of Water Environment Federation 71st Annual Conference and 

Exposition, October 1998, Orlando, Fla. 

PROJECT: Implementation of Restoration and Management Techniques (LA-6-802-S) 

ABSTRACT

Lake Apopka, a large, shallow, hypertrophic lake in central Florida, is the subject of an 

ambitious restoration program directed by the St. Johns River Water Management District. 

Well over $100 million of local, state, and federal funds have been provided to implement 

the restoration program. Initiation of the program is under way. The program has four 

major components: (1) P load reduction,( 2) removal of P stored in the lake and removal of 

suspended solids by wetland filtration,( 3) removal of P, restructuring of the lake’s food 

web, and reduction of internal P recycling by harvesting of shad, and (4)stabilization of 

sediments and creation of habitat by planting shallow areas. P load reduction is the most 

crucial aspect of the program. Without substantial reduction in the P load all other 

restoration actions would fail. This essential first step was initiated by efforts to reduce P 

loading from adjacent farmlands and will be completed by restoration of the majority of 

farmland to wetland and aquatic habitat. Acquisition efforts are expected to be complete 

by the fall of 1998. The components of the restoration program will work synergistically. 

As P load reduction reduces the P concentration, algal abundance will decline and water 

clarity will increase. Removal of P stored in the lake, through wetland filtration and shad 

harvesting, will further reduce the P concentration. Removal of suspended sediments by 

the wetland filter will future increase water clarity. Plantings will improve water clarity 

locally by reducing sediment resuspension. As water clarity increases, submersed plants 

can colonize and stabilize lake sediments with positive feedbacks to water clarity and 

negative feedbacks to the P concentration and algal abundance. A progressive cycle of 
Appendix H 

St. Johns River Water Management District

403 

plant colonization to greater depths and improving water clarity will return the lake to a 

macrophytes-dominated, clear-water condition. Since 1995, there have been significant 

improvements in the condition of Lake Apopka. It is likely that these improvements stem 

primarily from P load reductions associated with regulatory efforts. Shad harvesting, 

however, could have played a significant secondary role. 

Environmental Research & Design, Inc. 2001. Evaluation of water quality stormwater 

regulations for the Lake Apopka Basin. Draft final report submitted to St. Johns 

River Water Management District, Palatka, Fla. 

PROJECT: Nutrient Loading Limits Adoption (LA-3-403-M) 

INTRODUCTION

This report provides a summary of work efforts performed by Environmental Research 

& Design, Inc. (ERD) for the St. Johns River Water Management District (District) under 

Contract SD490AA to evaluate alternative water quality-based stormwater regulations 

for the Lake Apopka Basin. Previous research performed by the District has indicated 

that Lake Apopka is a phosphorus-limited ecosystem and, therefore, phosphorus inputs 

into the lake must be controlled to improve the existing hypereutrophic water quality 

characteristics. 

The primary objective of this study is to develop alternative stormwater regulations for 

the Lake Apopka Basin which maximize removal of phosphorus from runoff inputs. 

Based on research performed in Lake Apopka and an evaluation of phosphorus load 

reductions necessary to improve water quality in the lake, the District has established a 

general goal of no net increase in phosphorus loadings from nonpoint source inputs 

entering the lake. To achieve this goal, stormwater regulations must be developed 

which limit phosphorus loadings discharging from new developments to levels which 

are equal to or less than loadings discharging from the site under pre-development 

conditions. 

Evaluations performed by ERD for this project are based upon a combination of data 

sources, including (1) the draft District report by M.F. Coveney titled “Sedimentary 

Phosphorus Stores, Accumulation Rates, and Sedimentation Coefficients in Lake 

Apopka: Prediction of the Allowable Phosphorus Loading Rate,” dated May 10, 2000, 

which forms the basis for limiting post-development phosphorus loads to less than or 

equal to pre-development rates; (2) the draft District report titled “An External 

Phosphorus Budget for Lake Apopka 1989–1994” by Stites, Coveney, Battoe, and Lowe 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

404 

which provides estimated concentrations of total phosphorus in stormwater runoff 

entering Lake Apopka from typical land use categories; (3) existing District design and 

performance criteria for stormwater management systems outlined in Chapter 40C-42 

F.A.C.; and (4) previous research performed by ERD regarding performance efficiency 

of typical stormwater management systems. 

This report is divided into three separate sections for presentation and discussion of 

project results. The first section provides an introduction to the report and summarizes 

work efforts performed by ERD. Section 2 contains a discussion of the methods of 

analysis used for establishment of hydrologic characteristics, runoff characteristics, and 

evaluation of treatment system performance. The results of the analyses described in 

Section 2 are presented in Section 3, including an evaluation of the performance 

efficiency of existing regulations and an evaluation of required alternative treatment 

options. 

Exponent, Inc. 2000 (draft). Analysis of avian mortality at the North Shore Restoration 

Area of Lake Apopka in 1998–1999. Prepared for St. Johns River Water 

Management District, Palatka, Fla. Bellevue, Wash. 

PROJECT: North Shore Restoration (LA-3-303-M) 

INTRODUCTION

Between mid-December 1998 and early March 1999, an outbreak of avian mortality 

occurred at the North Shore Restoration Area (NSRA) of Lake Apopka in central 

Florida. Dead birds of numerous species were recorded, although in terms of total 

numbers, the American white pelican (Pelecanus erythrorhynchos) was the most affected 

species. More than 400 mortalities were recorded for this species at the NSRA, and 

similarly high mortality was seen at offsite locations. 

The NSRA lies on former agricultural land that was used for the production of 

vegetables and market crops. Due to past agricultural pest control practices, soils of the 

NSRA contain elevated residues of organochlorine pesticides, including toxaphene, 

DDT and its metabolites, and dieldrin. When the agricultural lands were acquired by 

the St. Johns River Water Management District (SJRWMD) in 1998, they remained 

flooded, a practice used by farmers after harvesting to control nematodes. The shallowwater habitat thus created was attractive to resident and migratory birds, and resulted 

in a huge influx of many species of birds to the NSRA. When the mortality outbreak 
Appendix H 

St. Johns River Water Management District

405 

began, it was believed by wildlife agencies that the elevated organochlorine pesticide 

levels in flooded soils, particularly toxaphene levels, likely caused the mortality. 

Exponent was retained by SJRWMD to investigate the mortality event, specifically to: 

• Analyze the underlying causes of the bird mortality at the NSRA 

• Determine the levels of pesticides in muck soils that are protective of birds, if pesticides 

are the cause of mortality 

• Determine the most effective management options for preventing such mortality 

events from occurring in the future. 

This technical report addresses the first objective and summarizes our review of key 

components of the mortality event to analyze the evidence that supports or refutes 

organochlorine pesticides, specifically toxaphene, as the causal agent of the mortality. 

As single approach or measurement endpoint is definitive for assigning causality, this 

report uses a weight-of-evidence that relies on several different components to evaluate 

causality. The components that are evaluated include: 

• Avian population census and mortality data 

• Food-web modeling to evaluate exposure of avian species to organochlorine pesticides 

• Body residues of organochlorine pesticides in dead birds 

• Etiology and pathology of the mortality event. 

Each of these components is addressed separately in the following sections, and results 

are summarized in the Conclusions section where an epidemiological approach is used 

to evaluate causality. A summary of issues pertaining to analytical methods for 

toxaphene analysis, which arose from the review of bird tissue data, are included as an 

appendix to this report. 

Fulton, R.S. 1998. Evaluation of drawdown as a restoration technique for Lake Apopka. 

Technical memorandum 27. St. Johns River Water Management District, Palatka, 

Fla. 

PROJECT: Drawdown and Lake Level Fluctuation (LA-2-208-F) 

EXECUTIVE SUMMARY

If excessive external nutrient loading can be controlled, drawdown is one potential 

mechanism to shift shallow eutrophic lakes from an algal-dominated to a macrophyte-
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

406 

dominated stable state. The principal objective of drawdown of Lake Apopka is 

considered to be re-establishment of diverse and healthy populations of native aquatic 

vegetation, fish, and wildlife. Extensive beds of submersed and emergent aquatic 

vegetation are necessary to realize the desired improvements in fish and wildlife. 

Potential costs, economic impacts, and environmental effects were considered for three 

drawdown options for Lake Apopka: 

• Gravity drawdown to 63.5 ft NGVD 

• Pumpdown to 61 ft NGVD 

• Pumpdown to 58 ft NGVD 

All drawdown options evaluated included a three-month holddown period, with 

passive refill of the lake from rainfall, runoff, and spring discharges. The timing of 

drawdown was planned so that the holddown period would occur during the spring 

germination period for wetland vegetation and refill would begin during the summerfall rainy season. Simulation modeling of the alternative drawdown options was 

conducted using an existing hydrological model of Lake Apopka. Predicted time to 

reach the target holddown elevation ranged from five to eleven months. For the gravity 

drawdown, predicted time from beginning of drawdown to completion of refill was 

about two years under high rainfall and three years under low rainfall. For the 

pumpdown options, predicted time to completion of refill was about three years under 

high rainfall and four years under low rainfall. 

Proposed design components of a drawdown included construction of a water retention 

structure around Apopka Spring to prevent the spring from discharging to the lake 

during the drawdown period (optional for gravity drawdown), dredging of a channel 

from the discharge structure to deep trenches in the lake to convey water and allow 

access for gill-net fish harvesting, the use of the Lake Apopka marsh flow-way to filter 

discharged water, and construction of a barrier across the Apopka-Beauclair Canal at 

the existing constriction to prevent backflow into Lake Apopka. 

Gravity drawdown would not consolidate a significant area of sediments, but would 

result in erosive removal of flocculent sediments from shallow littoral areas, reducing 

sediment depth and increasing bulk density of remaining sediments, which should 

improve conditions for plant establishment (6–18% of lake area). The pumpdown 

options would consolidate a significant portion of Lake Apopka sediments (4–24% of 

lake area), but would also result in a large area of partially consolidated sediments (20–

66% of lake area), which are prone to uprooting and forming floating vegetation islands 

after lake refill. 
Appendix H 

St. Johns River Water Management District

407 

Vegetative responses to drawdown of Lake Apopka are likely to be primarily invasive 

exotic (hydrilla) and native (cattail) plant species. Costs for management of the invasive 

vegetation could be as much as $17 million. Control of invasive vegetation would 

conflict with a major objective of drawdown, to stimulate sufficient growth of native 

aquatic and wetland vegetation to utilized excess nutrients, dampen wind resuspension 

of sediments, and provide aquatic habitat. Planting of desirable vegetation in 

conjunction with drawdown would be more compatible with restoration objectives, but 

planting 10,000 acres of desirable vegetation would cost an estimated $90 million and 

would not eliminate the need for control of invasive vegetation. Experience from 

drawdown of other lakes and analysis of available data indicates that much of the 

vegetation recruited during the drawdown would not persist long after refill unless 

other measures are taken to improve water quality in the lake. 

Reduction of nutrient loading is estimated to provide water clarity suitable for plant 

establishment over a large part of the area of Lake Apopka, regardless of whether or not 

a drawdown is conducted. Improvements in water clarity in Lake Apopka, resulting 

from nutrient loading reductions are also expected to increase management costs for 

invasive vegetation. However, it is expected that water clarity improvements will occur 

gradually, and the resulting responses by invasive plant species can be managed by a 

low-level maintenance program. 

Drawdown is not likely to improve water quality in Lake Apopka. There will probably 

be a substantial increase in phosphorus concentrations in Lake Apopka following refill, 

due primarily to a large increase in diffusive flux from lake sediments. Sediment 

dredging to prevent the diffusive flux would be prohibitively expensive. Over time, 

diffusive fluxes and water column nutrient concentration will probably decrease, but 

would not be expected to fall below pre-drawdown levels unless there is a significant 

decrease in external nutrient loading. 

The Lake Apopka marsh flow-way could be used to filter water discharged during 

pumpdown, and perhaps during gravity drawdown, to reduce water quality impacts 

on downstream lakes. However, estimated sediment discharges from pumpdown of 

Lake Apopka are sufficiently to completely fill both the Lake Apopka marsh flow-way 

and Lake Beauclair. Sediment accumulations would be likely to significantly affect 

benthic fauna and existing vegetation in both the marsh flow-way and in downstream 

lakes. 

Pumpdown of Lake Apopka would greatly increase nutrient loads to downstream 

water bodies and substantially increase nutrient concentrations, particularly in Lakes 

Beauclair and Dora, even if the discharge was filtered through the Lake Apopka marsh 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

408 

flow-way. Gravity drawdown would likely have a measurable detrimental effect on 

water quality only in Lakes Beauclair and Dora. 

Heavy fish mortality is likely to result from the pumpdown options. Following refill, 

conditions for fish recruitment are likely to be improved in Lake Apopka under all 

drawdown options, although it is not possible to project the magnitude of fishery 

response from the limited available data. However, improvements in fish recruitment 

will probably be temporary, unless other actions are taken to improve water and habitat 

quality in the lake. Existing efforts to reduce external nutrient loading and improve 

aquatic habitat in Lake Apopka should support greater vegetative growth in the lake, 

which would be expected to prolong post-drawdown increases in fish populations. 

Preliminary cost estimates for the drawdown options are: 

Item Gravity drawdown Pumpdown to 61 feet Pumpdown to 58 feet 

Construction $0–$1,150,0001 $2,990,000 $4,025,000 

Other potential costs 

Boating access 

loss damages2

$78,100–$124,300 $112,100–$ 190,900 $129,400–$ 198,100 

Vegetation 

management3

$274,500–$1,712,200 $1,647,000–$10,273,500 $2,745,000–$17,122,500 

Gill-net fishery 

harvest 

$1,037,000 $1,037,000 $1,037,000 

1

Range dependent on whether or not a water retention structure is built to prevent discharge from 

Apopka Spring. 

2

Ranges are predicted damages for high and low rainfall simulations. 3

Ranges are estimated maximum vegetation management costs for cattail and hydrilla, respectively. 

As invasive vegetation developing after drawdown is likely to be a mixture of these two 

species, expected vegetation management costs would likely be intermediate. 

In summary, under current levels of external nutrient loading to the lake, drawdown is 

not expected to provide sustained benefits to the Lake Apopka ecosystem. It is expected 

that drawdown would not improve water quality in Lake Apopka, but would cause 

water quality deterioration and substantial sediment accumulation in downstream 

water bodies, and result in only temporary increases in aquatic vegetation (primarily of 

invasive species) and fish populations in Lake Apopka. It is recommended that a 

drawdown of Lake Apopka not be considered until external loading is reduced to 

approach the level specified in the draft Lake Apopka rule, which is five metric tons of 

phosphorus annually from controllable sources. Reductions in external phosphorus 

loading and other ongoing restoration actions may be sufficient to shift Lake Apopka 
Appendix H 

St. Johns River Water Management District

409 

from an algal-dominated to a macrophyte-dominated stable state, but the time period 

required for recovery is unknown. Drawdown, or other restoration measures, should be 

considered if it becomes clear that the targeted reduction in phosphorus loading will 

not yield the expected decrease in phosphorus concentrations, if decreases in 

phosphorus concentrations do not yield the expected increases in water clarity, or if a 

significant increase in vegetated aquatic habitat in the lake does not occur within one to 

two years after achievement of a substantial increase in water clarity. If a decision is 

made to conduct a drawdown, it is recommended that a gravity drawdown be 

implemented first, and the positive and negative effects be carefully evaluated for two 

years after completion of refill before considering a more extreme pumpdown of the 

lake. 

Gale, P.M., and K.R. Reddy. 1994. Carbon flux between sediment and water column of a 

shallow, subtropical, hypereutrophic lake. J. Environ. Qual. 23:965–972. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

ABSTRACT

Field and laboratory experiments were conducted to measure forms, storages, and flux 

of C in the water-sediment column of a shallow, subtropical, hypereutrophic lake. High 

gross primary productivity in the lake (1.4 ± 0.3 kg C m-2 yr-1) was not significantly 

correlated with any water chemistry parameters measured. This suggested that the 

phytoplankton community was functioning at maximum levels and under nutrient 

nonlimiting conditions. Major C input to the lake is through gross primary 

productivity, of which 90% is lost through heterotrophic and microbial respiration 

processes within the water column. Resuspension of the bottom sediments was a major 

of C into the water column, contributing 720 g C m-2

 yr-1. In comparison, diffusive flux of 

dissolved organic C from the sediment was minimal (1.2 g C m-2

 yr-1), as were external 

inputs into the water column (20 g C m-2

 yr-1). High productivity of this system has 

resulted in a net accumulation of C (as sediments) of 118 g C m-2

 yr-1. 

Gallagher, E.P., T.S. Gross, and K.M. Sheehy. 2001. Decreased glutathione S-transferase 

expression and activity and altered sex steroids in Lake Apopka brown bullheads 

(Ameiurus nebulosus). Aquat. Toxicol. 55:223–237. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

410 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

A number of freshwater lakes and reclaimed agricultural sites in central Florida have 

been the receiving waters for agrochemical and municipal runoff. One of these sites, 

Lake Apopka, is also a eutrophic system that has been the focus of several case studies 

reporting altered reproductive activity liked to bioaccumulation of persistent 

organochlorine chemicals in aquatic species. The present study was initiated to 

determine if brown bullheads (Ameiurus nebulosus) from the north marsh of Lake 

Apopka (Lake Apopka Marsh) exhibit an altered capacity to detoxify environmental 

chemicals through hepatic glutathione S-traserase (GST)-mediated conjugation as 

compared with bullheads from a nearby reference site (Lake Woodruff). We also 

compared plasma sex hormone concentrations (testosterone, 17-beta estradiol, and 11 

keto-testosterone) in bullheads from the two sites. Female bullheads from Lake Apopka 

had 40% lower initial rate GST conjugative activity toward 1-chloro-2,4-dinitrobenzene 

(CDNB), 50% lower activity towards p-nitrobutyl chloride (NBC), 33% lower activity 

toward ethacrynic acid (ECA), and 43% lower activity toward Delta5-androstene-3, 17-

dione (Delta(5)-ADI), as compared with female bullheads from Lake Woodruff. Enzyme 

kinetic analyses demonstrated that female bullheads from Lake Apopka had lower 

GST-catalyzed CDNB clearance than did female Lake Woodruff bullheads. Western 

blotting studies of bullhead liver cytosolic proteins demonstrated that the reduced GST 

catalytic in female Lake Apopka bullheads were accompanied by lower expression of 

hepatic GST protein. No site differences were observed with respect to GST activities or 

GST protein expression in male bullheads. Female Lake Apopka bullheads also had 

elevated concentrations of plasma androgens (testosterone and 11-ketotestosterone) as 

compared with elevated levels of plasma estrogen but similar levels of androgens as 

compared with male bullheads from Lake Woodruff. Collectively, our studies indicate 

the presence of reduced GST protein expression, reduced GST conjugative capacity and 

altered sex steroid homeostasis in female bullheads from a contaminated field site in 

Central Florida. The implications of these physiological alterations in terms of pollutant 

biotransformation and reproduction are discussed. 

Geonex. 1998. Lake Apopka demonstration marsh vegetation analysis. Submitted to St. 

Johns River Water Management District, Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 
Appendix H 

St. Johns River Water Management District

411 

INTRODUCTION

This report serves as a summary of the photointerpretive vegetation change analysis of 

the St. Johns River Water Management District’s Lake Apopka Marsh site from 1990 to 

1997. The analysis involved the photointerpretation and digitization of color infrared 

aerial photography taken of the project site for the following dates: November 1990, 

October 1991, November 1992, September 1993, September 1994, May 1995, October 

1995, May 1996, and April 1997. Vegetative species were identified and coded according 

to the Wetland Diagnostic Characteristics Classification System that was provided by 

the District. Digital coverages were analyzed to calculate acreage changes between 

vegetative species in the Demonstration Marsh and Full Marsh. 

Photointerpretation was completed for the North Marsh, South Marsh, and Full Marsh 

for the October 1995 and April 1997 dates. There was not full aerial coverage of the Full 

Marsh for the May 1996 time frame and only the North Marsh and South Marsh were 

photointerpreted for that date. Quality control was performed on all of the maps, which 

include the three that were photointerpreted by Geonex and six others that were 

compiled by other sources and supplied to us by the District for quality control. 

Godwin, W.F. 1989. Trophic structure manipulation project, Phase II, quality assurance 

project plan. St. Johns River Water Management District, Palatka, Fla. 

PROJECT: Trophic Structure Manipulation (LA-4-207-F) 

PROJECT DESCRIPTION

The historical degradation of the Oklawaha Chain of Lakes (Figure 3.1) and of Lake 

Apopka in particular has been well documented (Brezonik et al. 1978; EPA 1979a; Lowe 

et al. 1986; Tuschall et al. 1978). This progressive cultural eutrophication of the lake has 

resulted in the reduction or elimination of many former uses of the water body. Since 

Lake Apopka is the largest of the Oklawaha chain and the headwater source, any 

attempt to improve water quality in the remainder of the lakes should logically begin 

with Lake Apopka. 

The Surface Water Improvement and Management Act (SWIM) was enacted in July 

1987. This legislation asserted that many of the surface waters of Florida have become 

or are in danger of becoming degraded and the state was obligated through its various 

agencies to enhance the environmental and scenic characteristics of these surface 

waters. Water management districts, in conjunction with the Florida Department of 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

412 

Environmental Regulation (FDER) and other state and local agencies were charged with 

preparation of a plan to achieve the goal of enhancement of environmental and scenic 

values of water bodies designated as having regional or statewide significance. Lake 

Apopka was specifically identified as a high priority water body in need of restoration. 

Previous legislation (85-148, Laws of Florida) created the Lake Apopka Restoration Act 

and established the Lake Apopka Restoration Council (LARC). The District, in 

conjunction with FDER, other state and local agencies, and the LARC, was mandated 

the responsibility of determining environmentally sound and economically feasible 

restoration methods for Lake Apopka. 

A District plan for the restoration of the lake was subsequently completed (Battoe et al. 

1988). This plan called for the implementation of diagnostic studies on nutrient 

dynamics and budgets for the lake and for a series of feasibility studies to determine 

methods which might be applicable to restoration of Lake Apopka to Class III water 

quality standards. One of the feasibility study areas selected for funding was 

biomanipulation. 

The purpose of this pilot study is to determine if manipulation of the dominant 

planktivore population in a small hypereutrophic lake will result in measurable 

changes in the trophic structure of that lake. Data acquired during the project will be 

used to formulate a plan for nutrient and algal biomass reduction through manipulation 

of the rough fish population in Lake Apopka. Lake Beauclair will be used as the control 

for this experiment and an additional background data base will be established for Lake 

Apopka. The project will be conducted in three segments of approximately one year 

each following a preliminary screening and lake selection process. Segment I will 

consist of the establishment of a pre-manipulation database in the experimental and 

control lakes. During Segment II, the population of gizzard shad (Dorosoma cepedianum) 

will be removed from the experimental lake and database collection will continue in all 

lakes. In Segment III, database collection will continue and an evaluation will be made 

of any changes in the experimental lake following rough fish harvesting. The project 

will commence upon approval of the Quality Assurance Project Plan and continue for a 

36-month period. 

Sample types, parameters, and sample numbers for surface water quality, biological, 

and sediment analysis are shown in Tables 3.1, 3.2, 3.3, and 3.4. All field sampling 

(except fisheries) will be conducted by SJRWMD staff. 

Determination of fish community dynamics will be contracted to the Florida Game and 

Fresh Water Fish Commission and specific measurement parameters are detailed in the 
Appendix H 

St. Johns River Water Management District

413 

Scope of Work for Ichthyofaunal studies (Attachment 1) and in the Ichthyofaunal 

Studies Quality Assurance Addition (Attachment 2). 

Analysis of macro-zooplankton, bacterioplankton, and ciliated protozoa will be 

conducted under contract to the University of Florida. Specific parameters to be 

measured for the zooplankton contract are detailed in the Zooplankton Analysis 

Quality Scope of Work (Attachment 3), Table 3.4, and in the Zooplankton Analysis 

Quality Assurance Addition (Attachment 4). 

Sediment analysis will be contracted to Hunter/ESE, Inc. Parameters to be analyzed for 

this portion of the study are shown in Table 3.3. Total nitrogen and total phosphorus 

will also be analyzed. 

Laboratory analysis of surface water samples will be contracted to PPB Environmental 

Laboratories, Inc. Parameters to be measured are shown in Table 3.2. This contractor 

will also conduct the analysis of chlorophyll. 

Algal productivity sampling and analysis will be conducted by SJRWMD staff. 

Godwin, W., S.G. Coyne, and E.A. Gisondi. 1993. An evaluation of methods for removal 

of rough fish as a restoration technique for Lake Apopka. Technical memorandum 

3. St. Johns River Water Management District, Palatka, Fla. 

PROJECT: Trophic Structure Manipulation (LA-4-207-F) 

EXECUTIVE SUMMARY

The declining environmental quality of surface water in the Ocklawaha basin, and 

particularly in Lake Apopka, has been a subject of concern for various agencies and 

private citizens for over 40 years. 

In recognition of the persistent water quality and associated environmental problems in 

this basin, the 1985 Florida legislature directed the St. Johns River Water Management 

District, in conjunction with the Florida Department of Environmental Regulation, other 

state and local agencies, and the Lake Apopka Restoration Council, to initiate a pilot 

restoration program for Lake Apopka. This mandate was reiterated through the Surface 

Water Improvement and Management Act of 1987. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

414 

One potential restoration method selected for further research was manipulation of lake 

trophic structure (food chain composition) and export in-lake nutrients by depleting 

planktivorous fish stocks, primarily gizzard shad. Establishment of an efficient and 

cost-effective method for removing target-fish species was essential in implementing 

this restoration technique, and an accurate assessment of existing rough fish stocks was 

necessary in determining the efficacy of various fish removal methods tested. 

This project had three major goals. First, to determine the biomass of harvestable 

gizzard shad stocks in Lakes Denham and Apopka. Second, to test the effectiveness of 

fishing techniques in Lake Apopka which are most often used for harvesting openwater fish stocks such as gizzard shad. Third, to estimate the cost and extent of nutrient 

export from fish removal and compare the results with other potential methods. 

The District, in cooperation with the Florida Game and Fresh Water Fish Commission, 

initiated an effort to test methods for determining gizzard-shad biomass, and to 

evaluate techniques for shad removal. Three fish removal techniques were selected for 

testing: haul seine, gill net, and pound net. Two basic principles were established to 

guide this effort: (1) An acceptable rough-fish removal method must be practical and 

specifically applicable to Lake Apopka and (2) use of fish toxicant is not a viable option 

for rough-fish depletion because of the negative impact of leaving large masses of dead 

fish to decompose in the lake with attendant nutrient release. 

Use of a small lake for the pilot fish removal effort resulted in much lower cost for the 

work and allowed better control of the fish removal process. The selected lake, Lake 

Denham (256 acres), is near Lake Apopka and was similar in trophic state and food-web 

structure. 

Standard fish sampling techniques using blocknets with rotenone and experimental gill 

nets of mixed mesh sizes were found to be inadequate to provide accurate information 

on the abundance of gizzard shad in either Lake Denham or Lake Apopka; therefore, 

information on the composition of the total fish stock was not available for either lake 

and only limited information was available on gizzard shad biomass. In Lake Denham, 

blocknets showed a total gizzard shad biomass of 7 to 21 lb/acre during the same time 

period when 417 lb/acre of adult gizzard shad were removed from the lake by haul 

seine. Blocknet data from Lake Apopka were also highly variable and showed similar 

low biomass levels. Experimental gill net catches showed high variability with the 

season of the year. Gill net catch results from both Lake Denham and Lake Apopka 

showed an 84% to 89% decline between the months of January and June each year 

before and after the fish removal. Results from Lake Apopka samples also showed high 

seasonal variability. 
Appendix H 

St. Johns River Water Management District

415 

Because direct census of gizzard shad populations was not feasible using blocknets or 

gill nets, we used Lake Denham haul seine catch and effort data to estimate the 

abundance of harvestable gizzard shad in that lake at the beginning and end of the haul 

seine work by using a standard mathematical equation (Leslie Regression). This could 

not be done in Lake Apopka because the haul seine was ineffective there. In lieu of 

numeric data, we used anecdotal information and an assumed relationship between 

experimental gill net and haul seine catches to project a harvestable gizzard shad stock 

for Lake Apopka of about 10 million pounds. 

In Lake Denham, 35 seine hauls completed between January and April 1990 produced a 

total fish catch of 112,437 lb. Of this total, 87,057 lb (77%) were gizzard shad. Game fish 

species comprised 19% of the catch and other rough fish made up the remainder. A 

Leslie Regression analysis of 1990 haul seine catch and effort data showed an initial 

harvestable gizzard shad stock of 100,794 lb, or 394 lb/acre of lake surface. The 

harvestable stock remaining after completion of the haul seine effort was estimated at 

13,737 lb, or 54 lb/acre. In 1991, 13 seine hauls completed in May produced a total fish 

catch of 20,895 lb. Gizzard shad made up 96% (20,040 lb) of the total. The remainder of 

the catch was game fish species and other rough fish species. A Leslie Regression 

analysis of 1991 haul seine catch and effort data showed an initial harvestable gizzard 

shad stock of 22,679 lb, or 88 lb/acre of lake surface. The harvestable stock remaining 

after completion of the 1991 haul seine effort was estimated at 2,639, or 10 lb/acre. 

An analysis of 1990 Lake Denham haul-seine catch data indicated that the initial adult 

gizzard-shad stock was depleted by 86%. In 1991, the existing adult shad stock was 

depleted by 88%. The average cost of contracted fish removal by haul seine in Lake 

Denham was $0.26 per pound in 1990. A total of 609 lb of phosphorus and 1,915 lb of 

nitrogen were exported from Lake Denham by this fish removal. The contract cost of 

nutrient removal was $36.43 per lb for phosphorus and $13.62 per lb for nitrogen. 

Contract cost for the 1991 fish removal was inflated ($0.36 per pound) because only one 

contractor submitted a bid for the work; therefore, nutrient removal cost was not 

calculated for the 1991 haul seine work. 

In Lake Apopka, 12 seine hauls were conducted during a 3-week period in April and 

May 1990. The harvest of gizzard shad from this effort was only 3,475 pounds, even 

though some hauls covered an area of 160 acres. Because of the small haul seine catches 

in Lake Apopka, the data were not suitable for any meaningful analysis. Reasons for the 

low catch efficiency of the haul seine in Lake Apopka included high fish escapement 

due to the slow seine-closure rate in the flocculent sediments, and the haul-seine 

contractor’s lack of detailed knowledge of fish and sediment distribution in Lake 

Apopka. The contractor was unable to compensate for these problems within the time 

and budget constraints of this contract. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

416 

Two commercial gill nets totaling 400 yards in length were used for fish removal trials 

in Lake Apopka during a 9-day period in January and February 1991 and a 13-day 

period in May 1991. In 184 hours of fishing effort, 40,521 pounds of fish were harvested. 

The catch by weight was composed of about 96% gizzard shad, 3% other rough fish, 

and almost 1% game fish. All game fish taken in the gill nets were of harvestable size. 

Initial mortality of game fish released from the gill net averaged less than 10% and 

occurred only during the warm-weather period (May). No estimate of longer term 

mortality of released fish was made. The cost of rough-fish removal by this method was 

$0.25 per pound. This figure is probably inflated due to the lack of highly competitive 

bidding for this fish removal contract. Many gizzard shad fishing operations routinely 

harvest fish by gill net at a market price of $0.08 to $0.15 per pound. 

We used comparative data from experimental gill nets in Lakes Denham and Apopka, 

the 1990 Lake Denham haul seine catch data, and reported catch efficiencies for gill net 

fisheries on migratory species to predict a potential annual shad removal of about 3 

million pounds for Lake Apopka. Use of gill nets appears to offer the best potential to 

achieve the target fish removal. However, this activity must be approved and permitted 

by the Florida Game and Fresh Water Fish Commission. Their evaluation of the impact 

of the game fish by-catch from gill nets will likely determine the future use of this fish 

removal method in Lake Apopka. 

Cost for removal of nutrients by gizzard shad harvesting appears to be lower than other 

methods and fish removal appears to be less problematic than other lake restoration 

alternatives associated with nutrient reduction such as sediment removal, pumped 

drawdown, alum treatment, or biochemical and chemical oxidation technology. We 

project that rough fish harvesting could remove about 11 tons of phosphorus and 33 

tons of nitrogen annually from Lake Apopka. Although this level of nutrient depletion 

alone will have only small effects on overall nutrient dynamics for the lake, it could 

augment significantly the projected annual phosphorus removal of 33 tons resulting 

from operation of a large water filtration wetland located adjacent to the lake. The largescale removal of gizzard shad could also produce beneficial food web effects in the lake. 

Gottgens, J.F., and T.L. Crisman. 1992. Newnans Lake, Florida: Removal of particulate 

organic matter and nutrients using a short-term drawdown (Phase I). Special Publication 

SJ92-SP23. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Drawdown and Lake Level Fluctuation (LA-4-208-F) 
Appendix H 

St. Johns River Water Management District

417 

EXECUTIVE SUMMARY

Water-level stabilization is commonly employed in Florida to insure year-round access 

to lakes. However, stabilized water levels may cause accelerated accumulation of 

nutrient-rich detritus on the lake bottom. This, in turn, can affect aquatic plant 

communities, reduce water clarity, and eliminate hard-bottom nesting areas for many 

sportfish. 

A 90-day gravity drawdown of shallow, algal-dominated Newnans Lake (Alachua 

County, Florida) was initiated by the Florida Game and Fresh Water Fish Commission 

in April 1989 by removing the flashboards on the outflow dam. The study reported here 

was designed to measure discharge rates of organic matter and nutrients through 

flushing and to examine the oxidation and consolidation of exposed littoral substrate in 

the field and in the laboratory. Sediment characteristics and patterns of sediment 

deposition and redistribution were also studied and are documented in the Phase II 

report (Gottgens and Crisman 1992). 

Temporary removal of the flashboards on the dam flushed moderate amounts of 

suspended solids, particulate organic matter (POM), nitrogen (TKN), and phosphorus 

(TP) from the lake. Elevated concentrations of POM, TKN, and TP in the discharge were 

only noted during the first month of dewatering, when adequate head differential was 

present. Storms associated with high winds appeared to promote flushing of organic 

matter and nutrients, probably due to enhanced resuspension of bottom lake sediment. 

Field and laboratory tests did not demonstrate a net oxidative removal of organic 

matter from exposed areas of the lake bottom. Consolidated sediments remained firm 

after reflooding, providing improved habitat for rooted macrophytes and fish 

spawning. Gravity drawdowns are inexpensive and can be effective in removing 

organic matter and nutrients when they are initiated at high lake stage and coincide 

with frequent wind events. Routine application of this management technique may 

produce a periodic rejuvenation of the lake ecosystem in situations where water-level 

stabilization is required. 

Gottgens, J.F., and T.L. Crisman. 1992. Sediments of Newnans Lake: Characteristics and 

patterns of redistribution following a short-term drawdown (Phase II). Special Publication 

SJ92-SP24. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Drawdown and Lake Level Fluctuation (LA-4-208-F) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

418 

EXECUTIVE SUMMARY

The impact of lowering water level (by short-term drawdown) on deposition and 

redistribution of organic sediments was studied in eutrophic Newnans Lake, Florida. 

Sediment transfer was determined by matching marker horizons in pre-drawdown 

cores with those in cores taken at the same sites after water level returned to normal. 

These horizons were located by radio-isotope analysis or by direct field evidence of 

distinct stratigraphy. An average of 6.1 g m-2day-1 (N=3) of organic material eroded from 

the littoral zone by lowering the water depth from 62 to 30 cm for 8 weeks. Littoral 

sediments with low bulk density eroded fastest and bulk density of remaining substrate 

increased by an average of 250%. Short-term drawdowns can greatly enhance 

resuspension of fine littoral substrate. A record of redistribution of this material to the 

deeper portions of the lake was unclear. Of six profundal sites analyzed for this study, 

two showed evidence of sediment deposition due to drawdown. Since resuspension of 

fine sediments influences the ecology of a lake through habitat alteration, release of 

nutrients, high turbidity and enhanced oxygen demand, erosion processes must be 

considered when drawdowns are attempted. Finally, data from Phase I and Phase II of 

this work are summarized, and recommendations for the management of Newnans 

Lake are provided. 

Greening, H., and S. Doyon. 1990. Environmental and ecological effects of drawdown and 

enhanced fluctuation for Lake Apopka, Florida. Special Publication SJ92-SP24. Palatka, 

Fla.: St. Johns River Water Management District . 

PROJECT: Drawdown and Lake Level Fluctuation (LA-4-208-F) 

EXECUTIVE SUMMARY

The potential ecological and environmental effects of a drawdown or enhanced lake 

level fluctuation program for Lake Apopka were assessed by Dames & Moore for the St. 

Johns River Water Management District as a part of the Lake Apopka SWIM Plan 

initiative. An extensive literature review and personal interviews were used to 

formulate a synopsis of the ecological effects of water level drawdown as a 

management and restoration technique. The application of drawdown or enhanced 

water level fluctuation to the restoration of Lake Apopka was addressed by evaluating 

the drawdown and enhanced fluctuation literature and existing studies on Lake 

Apopka. 
Appendix H 

St. Johns River Water Management District

419 

The literature review indicates that lake drawdown or enhanced water level fluctuation 

generally results in increased sportfish production, increased macrophyte-associated 

macroinvertebrate populations, and littoral zone habitat enhancement. Short-term 

control of nuisance vegetation frequently occurs in cold climates. Drawdown or 

enhanced fluctuation generally does not result in long-term improvements in water 

quality, or the control of nuisance macrophytes in warm climates. Significant sediment 

consolidation typically occurs only following long (>7 month) periods of sediment 

exposure, and usually only down to within 2 feet of the holddown lake elevation. 

The information gained from the literature review was applied to four drawdown/ 

enhanced fluctuation scenarios developed for Lake Apopka. These are: 

Scenario 1: Enhanced fluctuation by gravity flow and pumping from 66 ft NGVD (normal 

pool) to 63 ft NGVD. At 63 ft NGVD, only 8.6% (2,640 acres) of the total lake area will be 

exposed, although the lake volume will have been reduced by almost 60%. A minimal 

drainage canal system within the lake will be necessary. 

Scenario 2: Drawdown by gravity flow and pumping 62 ft NGVD. At this lake level 

elevation, 6,980 acres (22.7% of the total lake area) will be exposed and lake volume will 

have been reduced by almost 77%. A slightly more extensive in-lake drainage system will 

be needed. 

Scenario 3: Drawdown by gravity flow and pumping to 61 ft NGVD. At 61 ft NGVD, 

56.3% (17,357 acres) of Lake Apopka sediments will be exposed, while almost 90% of the 

original lake volume will have been discharged from the lake. Due to the relative isolation 

of some pockets of remaining water, an extensive in-lake system of drainage pipes or 

canals will be required to remove enough water to reach a water level of 61 ft NGVD in 

the lake basin. 

Scenario 4: Drawdown by gravity flow and pumping to 60 ft NGVD. At 60 ft NGVD, 85% 

(26,174 acres) of the total lake area will be exposed, with 95% of the original lake volume 

having been discharged. An elaborate system of miles of drainage canals or pipes will be 

required. 

The following in-lake effects of a Lake Apopka drawdown are likely to occur: 

• Extensive germination of littoral zone vegetation and increased littoral zone habitat. 

Under Scenario 1, increased germination may be minimal due to the small percentage 

of total lake sediments exposed. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

420 

• More extensive germination would be anticipated under other scenarios. Longevity of 

littoral zone habitat enhancement will likely depend upon the degree of sediment 

consolidation during exposure. 

• Increased sportfish populations as a result of increased littoral zone habitat, if sufficient 

stocks remain in Lake Apopka. 

• Extensive cattail germination and growth, likely requiring some degree of 

management (herbicide or mechanical harvesting), especially for Scenarios 2, 3 and 4. 

• Increased macrophyte-associated macroinvertebrate densities following refill but a 

decrease or elimination of some existing benthic species due to desiccation during 

dewatering. 

• Little or no improvement in water quality (TP, TN, and chlorophyll a concentrations) 

under all drawdown scenarios, based on results from other Florida lake drawdowns. 

• Development of a “cap” of consolidated sediments and germinated vegetation if the 

dewatering period is between three and seven months in duration, which can become 

dislodged from underlying unconsolidated sediments upon refill and cause “floating 

islands.” 

• Sediment exposure for longer than seven months will likely result in significant 

sediment consolidation down to within two feet of the holddown lake elevation. 

The duration of any effects of drawdown or enhanced water level fluctuation observed 

in Lake Apopka will likely be relatively short-lived (a maximum of 2–6 years). Potential 

effects of a drawdown or enhanced fluctuation on downstream water bodies include a 

possible shift in littoral zone plant community structure from nonaquatic species to 

aquatic species if maximum pool elevations in downstream lakes are maintained during 

Lake Apopka drawdown and holddown periods; excessive velocities in downstream 

channels during drawdown, with associated dislodging of sessile organisms; and the 

probability of significantly increased nutrient and sediment loading to downstream 

lakes during discharge and storage of Lake Apopka drawdown water. 

Gremillion, P.T., and C.E. Mericas. 1988. A literature review and feasibility analysis 

assessing microbial decomposition as a technique for restoring Lake Apopka. Special 

Publication SJ92-SP24. Palatka, Fla.: St. Johns River Water Management District. 
Appendix H 

St. Johns River Water Management District

421 

PROJECT: Microbial Decomposition (LA-4-205-F) 

EXECUTIVE SUMMARY

As part of the effort to improve water quality in Lake Apopka, International Science & 

Technology, Inc. (IS&T) has conducted a literature review and preliminary feasibility 

analysis assessing in situ sediment decomposition as a technique for oxidizing organic 

lake sediments and decreasing sediment nutrient loading to the water column. This 

technique applies biochemical or chemical processes, or a combination of both, and has 

its origins in wastewater treatment technology. 

Four specific techniques for sediment decomposition were investigated: microbial 

inoculation, denitrification, hydrogen peroxide addition, and ozonation. Thorough 

investigation of research and field applications of sediment oxidation techniques 

required a review of the peer-reviewed and “grey” literature, as well as interviews with 

scientists and lake managers with experience in this field and commercial vendors of 

these technologies. 

BACKGROUND

Decreasing the organic content of sediments has the potential for improving water 

quality in eutrophic lakes by decreasing the oxygen demand of the sediments on the 

water column, inhibiting nutrient cycling from the sediments to the water column, and 

increasing the depth of the water column through sediment consolidation. 

Natural systems accumulate excess organic material when biological productivity 

exceeds the capacity to decompose this material. This can be the result of nutrient 

limitation, the presence of toxins, or other adverse environmental conditions that 

constrain decomposition. Sediment treatment research focuses on accelerating decay 

processes through combinations of chemical, mechanical, and biological intervention. 

The sediments in Lake Apopka are moderately organic and subject to “intense 

microbial activity and anaerobic conditions” (Reddy et al. 1988). Anaerobic conditions 

are reflected in extremely high ammonium concentrations. Active denitrification is 

indicated by very low nitrate concentrations. The sediment has undergone significant 

microbial degradation, but the remaining degradable organic material in the sediments 

appears to be far from depleted, as reflected by the anaerobic conditions and high 

concentrations of ammonia. In addition, anaerobic conditions in the sediments may be 

sustained by the continual deposition of dead algal cells and allochthonous organic 

material. Sediment accretion rates average approximately 1 cm/year (Pollman, pers. 

comm.). 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

422 

BIOCHEMICAL OXIDATION TECHNIQUES

There are two technologies that attempt to induce microbial sediment oxidation. The 

first relies on the introduction of non-native microorganisms to both aerobic and 

anaerobic sediment environments. The second relies on native bacterial populations 

stimulated by introduced nitrate to oxidize sediments by denitrification under 

anaerobic conditions. 

Introduced Microorganisms. Non-native microorganisms are introduced into eutrophic 

lakes with the intention of removing particulate and dissolved organic material from 

the water column and sediments through enhanced aerobic and anaerobic bacterial 

activity, including denitrification. The products are composed of mixtures of bacterial 

species that are reported to be free of Salmonella and related pathogens. Most 

manufacturers of microbial treatments claim that their products work under both 

aerobic and anaerobic conditions, but that aerobic conditions are preferable and can be 

induced through mechanical aeration. 

Hanson (1981) conducted the most extensive investigation to date of in situ sediment 

digestion techniques, including aeration and microbial inoculation. The results 

indicated no detectable difference between sediments inoculated with the commercial 

product and the untreated controls. The author concluded that inoculating sediments 

with the correct mix of aerobes that have already developed the specific decay 

mechanisms required “may be very difficult, if it is possible at all.” Other researchers 

have reported similar negative results in evaluating the effectiveness of microbial 

inoculations (Jewell and McCarty 1970; Foree and McCarty 1971; Boyd et al. 1984; 

Tucker and Lloyd 1986; Muller 1987; Palmer et al. 1987; Blouin et al. 1988). 

The technology of microbial inoculation to improve water quality is based on highly 

controversial scientific theories. Controversy centers on the principal that if it is 

environmentally possible for a substrate to be used as an energy source, mechanisms 

will have developed over time to efficiently use that substrate. Given the general 

capability of native microbial populations to adapt to complex substrate types, the 

presence of excessive substrate (accumulated organic material) indicates that accretion 

rates are greater than the processing rates of the microbial population. This could be 

caused by nutrient limitation or toxicity (Jewell and McCarty 1971). Either of these 

conditions would also limit the effectiveness of introduced microorganisms (unless 

toxins to native populations were non-toxic to introduced microbes). 

The most compelling argument against the efficacy of commercial microbial products is 

the absence of published accounts of success in applying these products to eutrophic 
Appendix H 

St. Johns River Water Management District

423 

lakes. No support for the use of microbial inoculation as a lake restoration method can 

be found in the peer reviewed scientific literature. The few refereed journal articles 

documenting microbial inoculation conclude that the treatment is ineffective and 

theoretically unsound (Boyd et al. 1984; Hanson 1981). Without exception, the 

professional limnologists and aquatic scientists contacted during this investigation 

expressed the opinion that the addition of microbial products to promote sediment 

decomposition and lake restoration has little theoretical basis and no credible evidence 

to substantiate the claims made by the manufacturers. It was concluded that further 

investigation regarding the application of commercial microbial products to the 

restoration of Lake Apopka is not warranted. 

The cost of microbial inoculation can vary considerably, depending on whether 

mechanical aeration is included in the project design. Based on manufacturers’ 

recommended doses, areal costs range from $6 to $25 per hectare. These costs include 

only the purchase of the microbial product. Costs associated with application, 

environmental monitoring, or additional water conditioning, such as aeration or 

treatment with chemical precipitants, are not included. 

Nitrate Application. Lake restoration techniques involving nitrate application rely on 

the stimulation of biochemical denitrification. The principal objective is to inactivate 

sediment phosphorus through nitrate-induced reactions, but a related effect of the 

treatment is anaerobic sediment oxidation through denitrification. The mechanism of 

phosphorus inactivation is the sorption of phosphate onto insoluble ferric, Fe(III), 

oxides and hydroxides under oxidizing conditions. Cooke et al. (1986) observed that in 

shallow lakes with high pH and temperature, iron redox reactions may not control 

phosphate release. In such systems nitrate application may not inactivate phosphate, 

although sediment oxidation would still occur under reducing conditions. 

Laboratory studies by Hanson (1981) and Szewczyk (1984) examined the effectiveness 

of nitrate application in oxidizing organic sediments and found nitrate application to be 

a promising technology, concluding that readily degradable organic material was 

effectively decomposed without adverse impact to the water column. Neither 

investigator reported any reduction in sediment volume at any nitrate dose. 

Unfortunately, neither study examined the efficiency of denitrification or inhibition of 

phosphorus recycling. There are mixed, but generally positive reports of the success of 

nitrate addition treatments (Forsberg 1987; Lingren 1986; Ripl 1979; Willenbring et al. 

1984; Verner 1985; Ripl 1985; Foy 1986). 

The success of nitrate application appears to be related to site-specific conditions, 

including sediment chemical characteristics. It is evident that denitrification occurs 

intensely in the sediments in Lake Apopka. Thus, there may be substantial oxidation of 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

424 

organic material occurring routinely in the upper sediments of the lake. Conditions in 

the lake appear to be suitable for nitrate application; a shallow, subtropical system with 

a productive, aerobic, well-mixed water overlying the sediments. The capability for this 

technology to control phosphorus release in the highly productive environment of Lake 

Apopka is uncertain. Field investigations will be required to assess the efficacy of the 

technique. 

Ripl (1985) developed application technology and equipment, known as RIPLOX, to 

inactivate phosphorus and oxidize organic sediments through the addition of calcium 

nitrate in conjunction with lime and ferric chloride. This technology is marketed in the 

United States by Aqua Technique, distributor of the RIPLOX technology. Aqua 

Technique provides the mechanical apparatus for injecting calcium nitrate into lake 

sediments and the technical expertise in developing treatment designs for specific 

projects. Application costs for nitrate treatment depend on the specific dose of calcium 

nitrate needed and on whether additional chemicals, such as lime or ferric chloride are 

required. Treatment costs reported in the literature range from $0.74/m to $1.33/m. 

CHEMICAL OXIDATION TECHNOLOGY

Organic sediments can be decomposed by reactions involving chemical free radicals 

which form from compounds with highly reactive oxygen groups. The two chemical 

oxidants examined in this study, hydrogen peroxide and ozone, have been applied for 

both water treatment and lake sediment oxidation. Application of either technology 

would require isolating a several hectare area of lake and introducing either liquid or 

gas into the flocculent sediments. 

Hydrogen Peroxide. Hydrogen peroxide (H2O2) is commonly used in wastewater 

pretreatment for BOD, odor, and solids removal (Cole et al. 1974, 1976; Weber 1972). 

Research in the use of H2O2 for lake management has been conducted in field 

experiments by Barroin (1980) and laboratory experiments by Barroin and Feuillade 

(1986), Hanson (1981), Soares (1980), and Szewczyk (1984). Soares (1980) conducted 

laboratory studies on the biological effects of H2O2 application to eutrophic lake 

sediments. H2O2 treatments resulted in the complete elimination of benthic macrofauna, 

and possibly microflora as well, with subsequent recolonization by sulfur-reducing 

bacteria. Mortality resulted from oxidation by the H2O2, but also by H2O2 reaction 

products such as sulfide, ammonium, and copper. Following oxidation, the onset of 

reducing conditions was observed, presumably brought on by the renewed activity of 

reducing bacteria. The H2O2 application was effective in removing 30% of the COD. 

Hanson (1981) and Szewczyk (1984) included hydrogen peroxide treatment in their 

studies of in situ sediment consolidation techniques. Hanson reported highly efficient 
Appendix H 

St. Johns River Water Management District

425 

oxidation of organic sediments with increases in concentrations of dissolved carbon, 

phosphorus, and nitrogen and pH depression in the water column. He concluded that 

H2

O2 treatment was the most effective method tested. The author recommended a posttreatment lime application to adjust pH, and a final treatment for uptake of soluble 

nutrients and organic carbon, using either nitrate or aeration combined with microbial 

inoculation. Szewczyk (1984) concluded that while the sediment oxidation capacity of 

H2O2 was great, the high cost and adverse environmental impacts render the technology 

impractical. 

The effectiveness of chemical oxidation in lakes is offset to some extent by the profound 

impact of reaction by-products on overlying water quality. Followup treatment is 

necessary to precipitate nutrients from the water column. The choice of potentially 

applicable precipitants includes lime, alum, and ferric chloride, all of which are widely 

used in water treatment and lake management. Another secondary effect of chemical 

oxidation is a post-treatment pH decrease of 2 to 4 units. In-lake treatment operations 

(experimental or full-scale), will require a substantial secondary treatment program 

applying lime, or some other neutralizing agent to adjust the water column pH. It may 

be possible to use lime for both pH adjustment and precipitation. The extent of the 

treatment necessary will depend on iron concentrations in the sediment relative to the 

quantity of nutrients suspended. The cost of this additional treatment could easily equal 

or exceed the cost of initial oxidant application. 

The application of H2O2 on an operational scale would be logistically complex and labor 

intensive. Liquid hydrogen peroxide is available in bulk as a 35% or 70% solution. The 

35% solution has a cost of $0.107/kg, not including delivery. Cost for treatment is 

approximately $48/m. Additional costs would include product delivery, application 

equipment costs, and labor. 

Ozone. Ozone (O3

), like H2O2, is used in water treatment for its powerful oxidizing 

capability but is poorly documented as a lake management technology. Other than a 

project report (Water Management, Inc.), Hanson (1981) provides the only known 

report of ozone application to oxidize lake sediments. Oxidation of organic material was 

significantly lower than H2

O2 treatments and was comparable to removal observed in 

nitrate treatments. Sediment volume decreased significantly. The response of the water 

column to sediment ozonation is analogous to that of H2O2 treatments, and the 

secondary treatment requirements are identical. 

Ozonation would probably be highly effective in decomposing the UCF and CF 

sediment fractions in Lake Apopka. Additionally, organic material in the water column 

would be oxidized, including phytoplankton cells. Secondary treatment with a chemical 

precipitant would remove the resulting soluble nutrients from the water column and 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

426 

seal the sediments with a relatively insoluble surface layer. The result would be a 

deeper water column with a more consolidated lake bottom, and environmental 

conditions conducive to the establishment of rooted macrophytes. 

Implementing an effective ozonation program on Lake Apopka would be logistically 

complex. Ozone can be generated on-site, eliminating the problem of bulk shipping 

highly corrosive liquids (e.g., H2O2). The nature of the treatment would require that 

confined areas be treated sequentially as batch reactors. An enclosure in the lake would 

be required to hydraulically contain the area being treated. Following initial treatment 

with the chemical oxidant, the water would undergo treatment to remove dissolved 

nutrients and suspended residual organic material. After completion of the treatment, 

the enclosure would be moved to a new area and the process would be repeated. 

Traditionally, cost has been the limiting factor in applying ozonation as a treatment 

technology. Recent advances in ultraviolet (UV) light technology have resulted in the 

development of a relatively inexpensive method of generating a “highly reactive 

ionized oxygen gas plasma,” known as “activated oxygen,” and commercially 

produced under the trademark “PHOTOZONE” (Water Management, Inc.). The 

manufacturer claims that PHOTOZONE generation requires 3–5 kw hours to produce 

one pound of ozone, in comparison with 8–12 kw hours to produce one pound of ozone 

using conventional methods. PHOTOZONE has been used in lake management. 

Interestingly, the PHOTOZONE representative contacted for this study stated that 

PHOTOZONE no longer markets their product for lake management projects. 

Energy consumption will be the most expensive aspect of ozonation. Considering 

literature values of approximately 5 kw hr to generate 1 pound of ozone, Hanson’s 

(1981) ozone dose of 75 g O3/L of sediment, and energy costs of $0.041/kw hr (supplied 

by Florida Power and Light), energy costs to oxidize the UCF and CF sediments in Lake 

Apopka would be approximately $3 billion. 

PUBLIC HEALTH IMPLICATIONS

None of the biological or chemical products considered in this study appear to present a 

human health hazard. Genetically engineered organisms were specifically excluded. A 

possible public health risk indirectly related to any remediation efforts is the release 

from the sediments (and consequent activation) of the pathogenic amoeba, Neaglaria 

fowleri. This organism has been demonstrated to cause disease and death in humans in 

subtropical waters including lakes in central Florida. Generally the organism exists as a 

non-pathogenic encysted form in sediments until water temperatures exceed 

approximately 32o C, whereupon it converts to a free-living form and can enter the 

human body through mucous membranes. The existence of this organism in Lake 
Appendix H 

St. Johns River Water Management District

427 

Apopka has not been investigated for this study. However, prior to implementation of 

in-lake restoration activities, population studies are recommended to determine initial 

densities and, more important, to determine what, if any, effects may result from largescale disturbance of the organic sediments that may harbor the dormant cysts of this 

organism. 

CONCLUSIONS AND RECOMMENDATIONS

Of the technologies examined in this study, nitrate application and ozonation exhibited 

potential for immediate field testing in Lake Apopka. Chemical oxidation technologies 

would be substantially more costly than nitrate application (Table E-1). The cost of 

initial application alone to Lake Apopka would probably exceed $3 billion for ozonation 

and $7 billion for hydrogen peroxide application, and extensive secondary treatment 

would be required in addition to that cost for water quality mitigation. Nitrate 

application, was therefore selected as the most economical and technically feasible in 

situ lake restoration technique. Specific conclusions and recommendations regarding 

each technology are provided below. 

The theoretical framework that describes the mechanisms by which microbial 

inoculation should work is not supported by experimental data and is highly 

controversial. There is no evidence to indicate that application of this technology to 

Lake Apopka would bring about the desired responses of sediment decomposition or 

suppressed nutrient cycling. The technology of microbial inoculation currently provides 

a very low probability of success in field applications. Field tests of this technology are 

not recommended. 

The injection of calcium nitrate into anaerobic sediments has been demonstrated to 

oxidize organic sediments through denitrification and inactivate phosphorus through 

co-precipitation with ferric hydroxide. The chemistry and biochemistry of the processes 

involved in this technology have been established through field and laboratory 

experimentation. Thus, there is adequate theoretical and practical information available 

to develop reasonable designs for field trials of the technology. Field evaluation of this 

technology is recommended. 

Published reports of field and laboratory experiments using H2O2 and ozone show them 

to be highly effective in oxidizing organic sediments. Any application of chemical 

oxidation technology must be followed by treatment to inactivate dissolved nutrients 

and residual particulate organic material. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

428 

It is recommended that H2O2 and ozonation not be considered for field tests, because of 

excessive treatment costs and the logistic implications of large-scale treatment 

operations (e.g., bulk H2

O2 or ozone generation requirements). 

Gross, T.S., and N. Kernaghan. 2002. Endocrine disrupting effects of chlorinated 

hydrocarbons in fish and alligators in central Florida. SIS#1998. Progress report 

accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_

Projects]. Florida Caribbean Science Center, Gainesville. 

PROJECT: Fishery (LA-4-107-D) 

PROGRESS

The results from year 3 efforts continue to demonstrate endocrine disruption in wildlife 

(fish and alligators) for lakes from central Florida. These endocrine-disrupting effects 

are observed in association with and strongly correlated to increased concentrations of 

chlorinated hydrocarbon environmental contaminants. Although, our experimental 

efforts with DDE clearly indicate endocrine-disrupting effects in largemouth bass and 

alligators, they do not support our previous hypothesis of a causative relationship 

between DDE and altered egg hatchability in alligators. However, our year 3 results do 

indicate a significant relationship between DDE exposure and alligator neonatal 

mortality as well as altered neonatal immune function. Our efforts also suggest the 

utility of gonadal culture techniques as testing and screening methods for the effects of 

chlorinated hydrocarbons on gonadal steroidogenesis. Overall, these experimental 

efforts indicate contaminant induced endocrine disruption in wildlife and several 

effective biomarkers (i.e., estradiol, testosterone, 11-ketotestosterone, virellogenin, etc.) 

with which to study these effects. These methods should enable continued evaluation of 

wildlife populations, most critically evaluations of wildlife populations in contaminated 

sites currently undergoing reclamation. The ongoing examination of wildlife within 

these reclaimed muck farm sites demonstrates the utility of our biomarkers as a valid 

monitor of reclamation success and wildlife reproductive/endocrine health. 

Gross, T.S., M. Sepulveda, S.D. Ruessler, J.N. Wiebe, and C.M. Wieser. 2002. Microcosm 

and mesocosms evaluation of the bioaccumulation of chlorinated pesticides in the 

North Shore Restoration Areas. SIS#4944. Progress report accessed on 3/4/02. 
Appendix H 

St. Johns River Water Management District

429 

Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current

_Projects]. Florida Caribbean Science Center, Gainesville. 

PROJECT: Fishery (LA-4-107-D) 

PROJECT DESCRIPTION

During the fall of 1998 and winter of 1999, a significant bird mortality event occurred on 

the former agricultural property on the north shore of Lake Apopka, an area now 

known as the North Shore Restoration Area (NSRA). Although the cause of this event 

still is unclear, the USFWS has linked this mortality to organochlorine pesticide (OC) 

toxicosis. However, two risk assessments have failed to indicate a risk for acute 

mortality from OC concentrations in soil/sediments or in fish. Extensive evaluations of 

pesticides in the NSRA preceded and followed the bird mortality event. However, 

uncertainty remains concerning the causes of the mortality and concerning risks from 

OC pesticide residues in organic soils, and this uncertainty has limited the ability of the 

St. Johns River Water Management District and the NRCS to proceed with the 

restoration of the NSRA. A primary uncertainty for evaluating risk from OC pesticide 

residues is the rate of bioaccumulation of OCs from soils/sediments through the food 

chain to fish and then to birds. The OCs of potential concern in the NSRA are 

toxaphene, DDT and its metabolites DDE and DDD, and based on some bird tissue 

levels, dieldrin. In addition, the NSRA soils contain a high level of organic matter, 

which enable a high OC burden. Areas with similar high organic matter contents have 

not been studied, nor has environmental fate modeling for OCs been evaluated in these 

or similar high organic conditions. It is, therefore, unclear whether the magnitude of 

bioaccumulation reported for other extensively studied areas can be directly and validly 

applied to the NSRA. In addition, toxaphene has little or no bioaccumulation data in the 

literature. Therefore, three phases of study are necessary initial components of 

restoration efforts for the NSRA: (1) laboratory microcosms, (2) field-scale mesocosms, 

and (3) bird feeding studies. Previous ecological risk assessments have utilized the 

biota-sediment accumulation factor (BSAF) to estimate the bioaccumulation of OCs 

from sediments into the food chain, including fish and ultimately birds. Indeed, 

macroinvertebrates, amphibians, and fish serve as important and critical links in the 

transfer of sediment-associated chemicals to higher trophic levels, such as birds. The 

BSAF is a relatively simplistic environmental fate model that characterizes the 

bioaccumulation of lipophilic OCs as a function of organic carbon in sediments and/or 

as a percent of lipid in aquatic organisms. However, little data currently exist for the 

primary OCs and at the high organic levels found in the NSRA. The proposed 

microcosm studies will enable the assessment/determination of BSAFs for OCs from 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

430 

soil/sediment in the NSRA. In addition to base funds, funding is also provided by the 

St. Johns River Water Management District. 

Gross, T.S., and M. Sepulveda. 2002. Chlorinated hydrocarbons and developmental 

toxicity in wildlife. SIS#4292. Progress report accessed on 3/4/02. Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current_

Projects]. Florida Caribbean Science Center, Gainesville. 

PROJECT: Fishery (LA-4-107-D) 

PROJECT DESCRIPTION

From human activity during recent decades, the environment has been contaminated 

with a variety of xenobiotic compounds. Indeed, contaminants have been found even in 

areas remote from direct industrial and other cultural influences. Though we know that 

these xenobiotics modify genetic, biochemical and physiological processes, the 

mechanisms by which they harm wildlife and humans is poorly understood. To fully 

understand how pollution by xenobiotic agents affects organisms, we must elucidate 

their mechanisms fro genes to ecosystems. The ubiquitous distribution of these 

contaminants and their multi-generational effects on reproductive, endocrine, and 

developmental systems demand that additional studies be performed. These studies 

should identify important animal indicators (sentinels) of contaminant exposure, as 

well as elucidate possible important markers, biomarkers, of modified function that 

could be used to develop diagnostic procedures. This project focuses on providing 

biochemical data needed to elucidate specific factors (e.g. hormones and proteins) as 

bioindicators of contaminant-induced modifications of biological function in wildlife. 

The broad program project goal is to identify sensitive toxic endpoints and sensitive 

populations for chlorinated hydrocarbon toxicity. As a portion of this program, this 

project will seek to evaluate the endocrine-disrupting effects of chlorinated 

hydrocarbon contamination on wildlife species within a central Florida lake, Apopka, 

with an associated EPA SuperFund site. This particular project will examine alligators 

and fish for endocrine-disruption, alterations of sexual development and the 

identification of biomarkers for contaminant exposure. Portions of this project will also 

be integrated with other projects that examine immuno-toxic effects, stress proteins and 

an evaluation of potentials for human health effects. This project, overall, will 

contribute to our ability to assess the environmental impact of chlorinated 

hydrocarbons on wildlife. 
Appendix H 

St. Johns River Water Management District

431 

Gross, T.S., and J. Wiebe. 2002. Immuno-toxicity and endocrine disruption in Lake 

Apopka alligator neonates. SIS#2002. Progress report accessed on 3/4/02. 

Available at 

[http://www.fcsc.usgs.gov/Environmental_Contaminants/Contaminant_Current

_Projects]. Florida Caribbean Science Center, Gainesville. 

PROJECT: Fishery (LA-4-107-D) 

PROGRESS

In studies now in progress concerning effects of endocrine disrupters on reproduction 

in alligators in Florida lakes, we observed that hatchlings from some clutches collected 

from Lake Apopka were weak, in some cases to the point of being unable to extricate 

themselves from their eggshells without assistance, and that many such hatchlings 

appeared to be anemic. We recently examined bone marrow, thymus, and spleen from 

such hatchlings, and compared their tissues to those of hatchlings from clutches 

collected from Lake Woodruff. We found that the bone marrow of Lake Apopka 

hatchlings was hypoplastic compared with that of the Lake Woodruff hatchlings, 

thereby probably accounting for the observed anemia. The spleens and thymuses of the 

Apopka hatchlings also appeared to be hypocellular, although not so profoundly as the 

bone marrow. From these observations it seemed likely that Lake Apopka alligators 

might have defects in immunity. To test this hypothesis, we conducted a preliminary 

experiment in which 6-month-old alligators hatched from eggs from Lake Apopka and 

from eggs from Lake Woodruff were immunized by injection of sheep red blood. Blood 

samples were collected for determination of antibody titers to SRBC. Mean titers for 

Lake Apopka alligators were significantly lower than those for the Lake Woodruff 

alligators. We interpret these results to strongly suggest that young Lake Apopka 

alligators suffer from defective T cell dependent humoral immunity, probably as a 

result of abnormal development and contaminant exposure. 

Gross, T.S., R. Roberts, J.M. de Oca, and H.F. Percival. In preparation. Sex reversal in 

freshwater turtles as a response to estrogenic environmental contaminants. 

University of Florida, Gainesville. 

PROJECT: Fishery (LA-4-107-D) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

432 

ABSTRACT

Previous efforts have demonstrated alterations in reproductive development and 

endocrine function for neonatal alligators (Alligator mississippiensis; 7, 8, 9) and turtles 

(Chrysemys nelsoni; 7, Gross et al., in preparation) from a contaminated lake in Florida. 

These data demonstrate demasculinization of neonates and suggest estrogenic-pesticide 

contamination as a contributing factor. The current study examined effects of several 

potentially estrogenic-environmental contaminants on reproductive development in a 

species of freshwater turtle, Chrysemys nelsoni. Eggs were incubated at 26°C and divided 

into several treatment groups: control (n=30), oil/ethanol (n=30), DDE, DDT, dicofol, 

atrazine, dieldrin, toxaphene or estradiol (1, 10, and 100 μg/egg; n=25 for each 

treatment type and dose). Only 83% of the control eggs hatched, whereas treated eggs 

exhibited an overall 62% hatchability. Allantoic fluids and gonads were collected at 

hatching and analyzed respectively for estradiol and testosterone, and histological sex 

identification. Allantoic estradiol concentrations increased in response to estradiol 

(regardless of hatchling sex) and toxaphene (for male hatchlings) but with little or no 

increase for other treatments. Allantoic testosterone concentrations were reduced 

following DDE, dicofol, DDT, atrazine, and dieldrin treatments, whereas toxaphene and 

estradiol treatments did not alter testosterone regardless of hatchling sex. Most 

important, treatments significantly altered the sex of resulting offspring (percent male): 

controls=90%, estradiol=13%, DDE=46%, DDT=76%, dicofol=83%, atrazine=73%, and 

toxaphene=63%. These results indicate that treatment of turtle eggs with estradiol or 

various endocrine-disrupting contaminants results in significantly altered gonadal 

endocrine function as well as sex reversal. 

Guillette, L.J., Jr. 1995. Endocrine disrupting environmental contaminants and 

developmental abnormalities in embryos. Human and Ecological Risk Assessment

1(2):25–36. 

PROJECT: Fishery (LA-4-107-D) 

CONCLUSIONS

Finally, how should the wildlife data be viewed? As stated above, these studies do not 

show cause and effect—they cannot, as there are no control populations! However, 

excellent data are available from laboratory studies which support the interpretation 

that the abnormalities recorded in many wildlife populations can be related to 

endocrine disruption during embryonic development. Our understanding of these 

problems in free-ranging wildlife populations is thus going to be based on a weight of 
Appendix H 

St. Johns River Water Management District

433 

evidence-ecoepidemiological-approach (Fox 1991). Like the intense ‘smoking and lung 

cancer’ debate of the last two decades, some critics today tell us there is no cause and 

effect relationship between wildlife health problems and environmental pollution. True, 

we can not prove a relationship between any pesticide and specific problems in free 

living wildlife or for that matter, human populations. It took an epidemic of lung cancer 

to provide the stimulus for the scientific community to obtain the weight of evidence 

needed to show that a relationship does exist between smoking and lung disease as well 

as to begin the change in societal perceptions and public health responses to tobacco 

use. Likewise, we will never have causal data on the relationship between most 

pesticides and specific health effects in humans—except on a serendipitous or an 

accidental basis—for it would be immoral and unethical to obtain such information 

through controlled experiments on humans. 

It is clear that over the last two decades a number of reproductive abnormalities have 

increased dramatically, almost to epidemic proportions. These include rises in breast 

and gonadal cancers, infertility, and birth defects of the reproductive tract. The 

explanation for these increases is still forthcoming but recent hypotheses suggest that 

these increases can be understood if they are considered as occurring during embryonic 

development. Rodent studies are showing us that these hypotheses are clearly valid. Do 

wildlife provide us with lessons for our own public health? Yes, and we should begin 

to look and listen more attentively. As similar problems of embryonic origin are 

recorded in wildlife and human populations, it suggests we look to the environment for 

the causal agents and it is important we test, with creativity and objectivity, all plausible 

hypotheses. 

Guillette, L.J., Jr., J.W. Brock, A.A. Rooney, and A.R. Woodward. 1999. Serum 

concentrations of various environmental contaminants and their relationship to sex 

steroid concentrations and phallus size in juvenile American alligators. Arch. 

Environ. Contam. Toxicol. 36:447–455. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

Recent studies have reported a number of abnormalities in the hatchling and juvenile 

alligators of Lake Apopka, Fla. (USA). These abnormalities include modifications of 

plasma concentrations of sex steroids in males and females as well as abnormalities in 

gonadal morphology, gonadal enzyme activity, and steroidogenesis. Embryonic 

exposure to environmental contaminants in the eggs has been hypothesized to be the 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

434 

causal agent for these changes. However, posthatchling exposure can also contribute to 

changes in reproductive and endocrine functioning. We have detected serum 

concentrations of 16 to 18 organochlorine pesticides or metabolites (OCs) and 23 of 28 

congener-specific polychlorinated (PCBs) examined in juvenile alligators from Lake 

Apopka, Orange Lake, and Lake Woodruff National Wildlife Refuge. Lake Apopka 

juveniles had significantly elevated serum concentrations of p,p’-DDE, dieldrin, endrin, 

mirex, oxychlordane, ΣDDTs, and ΣPCBs compared to juveniles from the other lakes. 

Further, we observed no correlations between serum contaminant concentrations and 

sex steroid concentrations (estradiol-17beta and testosterone). However, serum 

testosterone was significantly lower in males from Lake Apopka and Orange Lake 

compared to Lake Woodruff NWR. We did not observe relationships between phallus 

size or other body parameters and serum contaminant levels. Phallus size was smaller 

in males from Lake Apopka even after adjustment for body size. We suggest that the 

observations previously reported for juvenile alligators—and observed again in this 

study—are apparently not associated with the current serum levels of the 

environmental contaminants we measure, but could be due to exposures during 

embryonic development to these or other pollutants. Future studies must determine if a 

causal relationship exists between the contaminants found in alligator eggs and 

abnormalities observed in the hatchlings and persisting in juveniles. 

Guillette, L.J., Jr., and D.A. Crain. 1996. Endocrine-disrupting contaminants and 

reproductive abnormalities in reptiles. Comments Toxicology 5(4–5):381–399. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

Recent studies show that environmental contamination of reptiles is associated with 

population declines due to lethal and reproductive effects of the contaminants in 

embryos, juveniles, or adults, developmental abnormalities of embryos, including major 

teratogenic effects in turtles and more subtle effects on the development of the 

reproductive system of alligators, and abnormalities of the endocrine system. We 

examine the data available on abnormalities of the reproductive system in reptiles 

induced by endocrine-disrupting xenobiotics. We discuss the role of these xenobiotics in 

light of experimental evidence showing that estrogenic steroids are capable of 

stimulating sex reversal—male to female—in developing reptilian embryos exhibiting 

environmental sex determination. A hypothesis is presented suggesting that any 

compound that disrupts the normal steroid milieu of the developing embryo will have 

significant, life-long consequences on sex determination and the organization and 
Appendix H 

St. Johns River Water Management District

435 

function of the reproductive system. These endocrine-disrupting compounds may 

directly influence embryonic development by altering the steroid dynamics that 

facilitate sex determination. 

Guillette, L.J., Jr., D.A. Crain, A.A. Rooney, and D.B. Pickford. 1995. Organization 

versus activation: The role of endocrine-disrupting contaminants during embryonic 

development in wildlife. Environ. Health Perspect. 103(7):157–164. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

Many environmental contaminants disrupt the vertebrate endocrine system. Although 

they may be no more sensitive to endocrine-disrupting contaminants (EDCs) than other 

vertebrates, reptiles are good sentinels of exposure to EDCs due to the lability in their 

sex determination. This is exemplified by a study of alligators at Lake Apopka, Florida, 

showing that EDCs have altered the balance of reproductive hormones resulting in 

reproductive dysfunction. Such alterations may be activationally or organizationally 

induced. Much research emphasizes the former, but a complete understanding of the 

influence of EDCs in nature can be generated only after consideration of both 

activational and organizational alterations. The organizational model suggests that a 

small quantity of an EDC, administered during a specific period of embryonic 

development, can permanently modify the organization of the reproductive, immune, 

and nervous systems. Additionally, this model helps explain evolutionary adaptations 

to naturally occurring estrogenic compounds, such as phytoestrogens. 

Guillette, L.J., Jr., T.S. Gross, D.A. Gross, A.A. Rooney, and H.F. Percival. 1995. Gonadal 

steroidogenesis in vitro from juvenile alligators obtained from contaminated or 

control lakes. Environ. Health Perspect. 103(4):31–36. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

The ubiquitous distribution of many contaminants and the nonlethal, multigenerational 

effects of such contaminants on reproductive, endocrine, and immune systems have led 

to concerns that wildlife worldwide are affected. Although the causal agents and effects 

are known for some species, the underlying physiological mechanisms associated with 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

436 

contaminant-induced reproductive modifications are still poorly understood and 

require extensive research. We describe a study examining the steroidogenic activity of 

gonads removed from juvenile alligators (Alligator mississippiensis) obtained from 

contaminated or control lakes in central Florida. Synthesis of estradiol-17β (E2) was 

significantly different when ovaries from the contaminated and control lakes were 

compared in vitro. Additionally, testes from males obtained from the contaminated lake, 

Lake Apopka, synthesized significantly higher concentrations of E2 when compared to 

testes obtained from control males. In contrast, testosterone (T) syntheses from all testes 

examined in this study displayed a normal pattern and produced concentrations greater 

than that observed from ovaries obtained from either lake. Interestingly, the pattern of 

gonadal steroidogenesis differs from previously reported plasma concentrations of 

these hormones obtained from the same individuals. We suggest that the differences 

between the in vivo and in vitro patterns are due to modifications in the hepatic 

degradation of plasma sex steroid hormones. 

Guillette, L.J., Jr., T.S. Gross, G.R. Masson, J.M. Matter, H.F. Percival, and A.R. 

Woodward. 1994. Development abnormalities of the gonad and abnormal sex 

hormone concentrations in juvenile alligators from contaminated and control lakes 

in Florida. Environ. Health Perspect. 102:680–688. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

The reproductive development of alligators from a contaminated and a control lake in 

central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed 

due to an extensive spill of dicofol and DDT or its metabolites. These compounds can 

act as estrogens. Contaminants in the lake also have been derived from extensive 

agricultural activities around the lake that continue today and a sewage treatment 

facility associated with the city of Winter Garden, Florida. We examined the hypothesis 

that an estrogenic contaminant has caused the current failure in recruitment of 

alligators on Lake Apopka. Supporting data include the following: at 6 months of age, 

female alligators from Lake Apopka had plasma estradiol-17β concentrations almost 

two times greater than normal females from the control lake, Lake Woodruff. The 

Apopka females exhibited abnormal ovarian morphology with large numbers of 

polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly 

depressed plasma testosterone concentrations comparable to levels observed in normal 

Lake Woodruff females but more than three times lower than normal Lake Woodruff 

males. Additionally, males from Lake Apopka had poorly organized testes and 
Appendix H 

St. Johns River Water Management District

437 

abnormally small phalli. The differences between lakes and sexes in plasma hormone 

concentrations of juvenile alligators remain even after stimulation with luteinizing 

hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been 

permanently modified in ovo, so that normal steroidogenesis is not possible, and thus 

normal sexual maturation is unlikely. 

Guillette, L.J., Jr., D.B. Pickford, D.A. Crain, A.A. Rooney, and H.F. Percival. 1995. 

Reduction in penis size and plasma testosterone concentrations in juvenile 

alligators living in a contaminated environment. Gen. Comp. Endocrinol. 101:32–42. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

The development of the male reproductive ducts and external genitalia in vertebrates is 

dependent on elevated androgen concentrations during embryonic development and 

the period of postnatal growth. We have observed that a population of juvenile 

alligators living on Lake Apopka exhibit significantly smaller penis size (24% average 

decrease) and lower plasma concentrations of testosterone (70% lower concentrations) 

when compared to animals of similar size on Lake Woodruff. In addition to smaller 

phalli, no relationship exists between plasma testosterone concentrations and penile 

size in males form Lake Apopka, whereas a positive relationship exists for males form 

Lake Woodruff. The alligators on Lake Apopka are known to have elevated 

concentrations of the antiandrogenic DDT breakdown product p,p’-DDE stored in their 

fat. We suggest a number of hypotheses that could explain the modification in the 

phenotype of the juvenile male living in Lake Apopka. These modifications in 

phenotype include a smaller penis size, lower plasma androgen concentrations, and 

lack of responsiveness of the penis to the plasma androgens present. 

Hackett, W.C., and O.C. Thompson. 1991. Biofermentation pilot study for water hyacinth 

and gizzard shad composting. Special Publication SJ91-SP13. Palatka, Fla.: St. Johns 

River Water Management District. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 
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EXECUTIVE SUMMARY

A pilot study using biofermentation technology developed by Agron Corporation 

(South Charleston, Ohio) for composting gizzard shad and water hyacinths was 

conducted by Agron Corporation for the St. Johns River Water Management District. 

The purpose of this study was to determine if gizzard shad and water hyacinths can be 

composted into a product that has market value. Water hyacinths and gizzard shad are 

potentially harvested in large quantities from lake restoration, aquatic macrophyte 

management, and fisheries management programs. The subsequent transformation of 

this raw biomass into a marketable product could function as a partial or full subsidy 

for these restoration and management programs. 

Biofermentation is a process which utilizes naturally occurring aerobic bacteria to 

biologically alter the characteristics of organic waste. In this pilot study, different 

mixtures of water hyacinths, gizzard shad, poultry and cattle manure, and scallop offal 

were biofermented. It was found that water hyacinths alone do not ferment well. 

Biofermentation was greatly improved when gizzard shad, poultry or cattle manure, or 

scallop offal were used in conjunction with water hyacinths. In order to reduce the high 

moisture content of water hyacinths, some dehydration and mixing of the plant biomass 

with a high carbon material such as sawdust or newspaper was necessary. 

The 1:1 ratio of water hyacinths to gizzard shad biomass used in one of the 

biofermentation trials resulted in odor, fly, and maggot problems during all three stages 

of the biofermentation process. Consequently, future biofermentation trials using 

gizzard shad will have to reduce the relative proportion of gizzard shad to help reduce 

the chances for odor, fly, and maggot problems. None of these problems were observed 

in any of the other trials in this study; gizzard shad were used in only one trial, 

however. 

Recommendations made by Agron Corporation for future studies of water hyacinth 

and gizzard shad composting are incorporated into two additional study phases. Phase 

II would examine the effectiveness of the water hyacinth and gizzard shad Fermway 

(the biofermentation end-product) as a fertilizer on test plots of vegetables at nearby 

Lake Apopka muck farms. 

Should large-scale gizzard shad and water hyacinth harvesting programs be initiated in 

the restoration of Lake Apopka, a Phase III project could incorporate a full-scale 

biofermentation center which could utilize harvested water hyacinths and gizzard shad 

from the lake restoration efforts. A biofermentation center as outlined in Phase III could 

produce about 8,700 tons of Fermway per year. 
Appendix H 

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Havens, K.E., H.J. Carrick, E.F. Lowe, and M.F. Coveney. 1999. Contrasting 

relationships between nutrients, chlorophyll a, and Secchi transparency in two 

shallow subtropical lakes: Lakes Okeechobee and Apopka (Florida, USA). Lake 

Reserv. Manage. 15(4)298–309. 

PROJECT: Restoration Monitoring (LA-6-803-S) 

ABSTRACT

Ten years of monthly water quality data were compared from two large shallow lakes 

in Florida, USA—Lakes Okeechobee and Apopka. Seasonal changes in trophic state 

index (TSI) values and log-log regression models relating total phosphorus (TP), total 

nitrogen (TN), chlorophyll a (CHLA), and Secchi transparency (SD) were considered. 

The objective was to quantify the extent to which empirical models might vary due to 

the heterogeneous nature of benthic-pelagic coupling that can occur in shallow lakes. In 

the offshore region of Lake Okeechobee, TP and SD-based TSI values increase 

dramatically during winter, while CHLA-based TSI declines. These changes coincide 

with the windy season in south Florida, when average wind velocities can exceed 20 km 

h super (-1). Resuspension of bottom sediments occurs and this reduces light 

penetration to the extent that the growth of phytoplankton is inhibited. During summer, 

winds are calm, and these conditions occur less often. Log-log regression models of 

CHLA vs. TP have a negative slope during winter and a positive slope during summer 

in offshore Lake Okeechobee. The slope of SD vs. CHLA models displays the opposite 

seasonal pattern. Seasonal changes are considerably muted in the near-shore region, 

where sediments are more consolidated and where shallower depths reduce the 

severity of light suppression of phytoplankton growth. The magnitude of seasonal 

variation in TSI values in Lake Apopka is muted, perhaps because seasonal variation in 

wind velocity is less than in the region of Lake Okeechobee. Hypereutrophic levels of 

nutrients, CHLA, and SD occur year-round. The log-log regression models of CHLA vs. 

TP and CHLA vs. TN are highly significant, and light availability does not appear to 

limit rates of algal production. Frequent resuspension events may occur, but negative 

effects on phytoplankton may be mitigated by (1) shallower depth; (2) a greater 

presence of viable algae in the surface sediments that might “seed” the water column 

with phytoplankton; (3) high concentrations of soluble nutrients in sediments that 

might stimulate algal growth; and (4) lower concentration of light-attenuating inorganic 

particles than in Lake Okeechobee. The results indicate that a high degree of variability 

in both the seasonal patterns and relationships among nutrients, CHLA, and 

transparency can occur in shallow subtropical lakes, even when they share common 

features (e.g., geographic location, large size, wind patterns). This finding has practical 

implications regarding the use of regression models in the context of shallow lake 
SWIM Plan for Lake Apopka 

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management. Models may be quite useful on a lake-by-lake basis (e.g., in Lake Apopka 

they have successfully been used in eutrophication management), but considerable care 

should be taken when generalizing models to other lake ecosystems. 

Heaney, J.P., T.D. Feather, and M. Shafer. 1989. Development of a socio-economic assessment 

methodology with applications to the Lake Apopka Basin. Special Publication SJ89-SP5. 

Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Socioeconomic Assessment and Methodology (LA-2-209-F) 

SUMMARY

The purposes of this study were to develop an evaluation procedure and associated 

software for performing a socioeconomic assessment on a water project and to apply 

this methodology to the Lake Apopka Basin in central Florida. 

The socioeconomic analysis provides decision makers with valuable information on the 

benefits and disbenefits of each of the alternatives under consideration. A wide variety 

of techniques have been developed over the years to do these evaluations ranging from 

simple benefit-cost analyses to complex multi-objective optimization models. The 

federal government has sponsored development of standardized procedures for doing 

these analyses. The most recent summary of these methods is contained in the 

Principles and Guidelines (1983). These guidelines cover the following areas of water 

resources: municipal and industrial water supply; agricultural floods, erosion, 

sedimentation, irrigation, and drainage; and urban floods, hydropower, navigation, 

recreation, and commercial fishing. Conspicuously absent from this list is 

environmental quality which is not covered in the National Economic Development 

portion of the federal guidelines. Environmental quality is treated as a separate 

objective which is not quantified in monetary terms. Thus, additional effort was 

expended in incorporating this important purpose. 

The literature review of analysis techniques covered conventional benefit-cost analysis, 

multi-objective analysis, risk analysis, social choice modeling, expert systems, decision 

support systems, and environmental impact analyses. For the application to Lake 

Apopka, emphasis was given to two general categories of benefits: (1) agricultural 

irrigation, drainage, and flood damages, and (2) environmental quality, recreation, and 

property values. 
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The performance of a system can be described by its reliability, resiliency, and 

vulnerability. In order to analyze the full suite of benefits and disbenefits, it is essential 

to do a continuous simulation of how the system performs on a day-to-day basis. Also, 

it is essential to define threshold values outside (e.g., above or below) of which the 

system has “failed” and an “event” has occurred. The spreadsheet model presented in 

Chapter 3 allows these events of interest to be extracted from the database and input to 

the benefit estimation model(s). 

Flood and drought damages to agricultural areas can be estimated using a spreadsheet 

model called ADAM (Agricultural Damage Assessment Model) that does a detailed 

continuous month to month tracking of farm operations. Flood and/or drought events 

interrupt the planned activity and the farmer adjusts as best he can to reduce his losses. 

The model application to the muck farm areas north of Lake Apopka was presented in 

Chapter 4. 

The benefits of environmental quality enhancement include improved health, 

productivity, and recreation/aesthetics. Techniques exist for measuring the direct 

recreation benefits. Recently, techniques have also been developed to estimate the socalled non-user benefits. We prefer to use the name environmental quality (EQ) 

benefits, i.e., benefits that accrue to the general public from an improvement in 

environmental quality. These EQ benefits are the sum of: 

• Option value—value placed on having the option of using an environmental resource 

• Existence value—benefit of knowing an environmental resource exists 

• Bequest value—value of preserving a resource for future generations 

These EQ benefits have been shown to represent a significant part of total benefits 

because a strong general concern exists for protecting the environment, and a 

willingness to pay for such programs in order to protect not only nearby water supply 

or recreational facilities but also to support programs far removed from their locale, 

e.g., the Amazon. One reason that these EQ benefits are significant is the large number 

of people who derive these benefits. While survey techniques have been used to 

estimate EQ benefits, a more direct measure is available in Florida thanks to recent 

environmental restoration programs that have committed large funds to support these 

activities. Such commitments represent a direct measure of voluntary willingness to pay 

to clean up and/or protect vital areas such as Lake Apopka, Lake Okeechobee, the 

Indian River, Tampa Bay, and the Everglades. 
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442 

Procedures for evaluating recreation benefits using the unit day value method, the 

travel cost method, and the contingent value method are described in the literature. The 

results of these studies were summarized for various use categories. 

The socioeconomic methodology was used to estimate the benefits and disbenefits 

associated with the past and projected activities associated with Lake Apopka. This lake 

has been impacted by man’s activities for more than a century. The initial impacts on 

the lake were the result of a navigation canal, completed in 1893. This canal also 

lowered the lake level by four feet, leaving an estimated 20,000 acres of lake bottom dry 

enough for cultivation. However, it was not until the early 1940s when the Zellwood 

Drainage and Water Control District succeeded in developing a dike, canal, and pump 

system that provided adequate water management to bring this land under cultivation. 

In its natural state and through the 1950’, Lake Apopka was world renowned for its 

sport fishing. However, the fishing declined rapidly as the water quality of the lake 

continued to degrade due to continued back pumping of nutrient rich drainage waters 

from the muck farms into the lake. At present, the lake is one of the most polluted in the 

State of Florida and is the subject of major activities attempting to significantly improve 

its quality so that it can support a variety of recreational activities including fishing, 

boating, swimming, and passive recreation. 

The area around Lake Apopka has experienced very rapid population growth during 

the past thirty years with the population of Lake and Orange counties increasing over 

five-fold from 151,000 in 1950 to 816,000. Land use trends in the area indicate that the 

Lake Apopka area will experience a transition from agricultural to urban activities. 

The socioeconomic analysis is directed to estimating the benefits and disbenefits 

associated with man’s past, present, and projected uses of Lake Apopka. Benefits accrue 

due to uses of the lake that result in an enhanced profitability of activities due to water 

management activities such as lowering the lake level and installing protective works to 

permit intense farming activity on the muck lands at the north end of the lake. 

Disbenefits accrue when man’s activities degrade the quality of the lake’s water and/or 

modify the lake levels in such a way that other beneficial uses such as recreation are 

impaired or precluded. 

CONCLUSIONS

With regard to socioeconomic analysis techniques, a wide variety of methods have been 

developed in the past thirty years. The emphasis has been on normative optimization 

models that can prescribe the optimal solution. Unfortunately, it is necessary to greatly 

simplify the description of the actual problem to satisfy the rigid strictures of the 
Appendix H 

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optimization models, e.g., linear functions, normal distributions, simple production 

functions. Thus, the results may not be a realistic appraisal of the actual situation. 

Because of this focus on modeling, databases have not been developed on benefits, 

costs, risk levels, etc., or how these impacts are distributed among the affected groups. 

Thus, our approach was to use standard benefit-cost analysis procedures with an 

emphasis on developing reliable databases for conditions that exist in the St. Johns 

River Water Management District and related areas. 

It is essential to develop quantifiable measures of system performance, than to actually 

measure these quantities and see how well they perform against prespecified criteria 

such as keeping the lake stage above a pre-set elevation. Given such a system, it is 

possible to directly evaluate performance and suggest improved operating policies. 

However, in the absence of actual and not just estimated values, it is difficult to develop 

cogent control strategies. 

A continuous simulation model is essential to evaluate the socioeconomic impacts of 

various water management strategies on farming activities and vice versa. The lake 

regulation schedules affect the rate at which water seeps into the muck farms. The 

farmers’ activities affect the lake levels and its quality through their significant 

pumping activities during and following storm events. The farmer has a relatively wide 

variety of choices available including the selection and timing of crops, the design and 

operation of the water management system, and the method of response to high or low 

water stress conditions. Ideally, the simulation model could incorporate these decision 

rules into the analysis. This would require close cooperation with the farmers since they 

best know their operation. 

For Lake Apopka, the public has committed about $40 million to help restore this lake. 

Averaging this commitment over the 800,000 people living in Orange and Lake 

counties, we obtain a current cost of $50/capita. Amortizing this expenditure over an 

infinite planning horizon at an interest rate of 10% yields an equivalent benefit or 

willingness to pay of $5.00/capita/year. Equivalently, the damages to these people 

from the present state of Lake Apopka are at least $5.00/capita/year. 

The primary gap in recreation benefit assessments is lack of site-specific data. The 

methodology is straightforward. 

The results of the application of the socioeconomic procedures to Lake Apopka were 

summarized in Figures 6-19. The diking and pumping activities have allowed high 

valued agricultural activity to thrive in the muck farm area north of Lake Apopka. 

Based on a detailed modeling of monthly agricultural activities, the estimated present 

net revenue from the muck farm activities is $6.4 million per year. This value is 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

444 

assumed to be constant (as measured in 1989 dollars) over the 60-year period from 1960 

to 2020. This gain represents a private gain in that the farmers are able to capture all of 

these net revenues. Offsetting this gain are three categories of losses: decreased direct 

recreation values, lowered environmental quality to the general public, and decline in 

property values to the riparian owners. The losses in direct recreational value range 

from a low of $1.14 million in 1960 to a high of $4.6 million by the year 2020. The 

primary recreation value affected is boating activities. The largest loss is the loss in 

environmental quality suffered by the general public. The equivalent annual per capita 

loss is $5.00 per capita per year. This loss ranges from $0.8 million in 1960 to $6.93 

million by the year 2020. The reason that this loss increases so substantially is that the 

population in the year 2020 is expected to be nearly four times greater in 2020 than it 

was in 1960, an increase from 321,000 to 1,259,000. The last loss category is the loss in 

value of waterfront property along Lake Apopka. This loss is estimated to be a constant 

$0.2 million per year based on a decrease in water front property value of $100 per front 

foot. 

The net effect of these gains and losses is that a positive net benefit accrued during the 

early years of muck farming. However, by the 1980s, the net value became negative, 

and it is projected to become increasingly negative in the future if restoration is not 

done. The projected annual loss by the year 2020 is $4.73 million per year. 

The citrus groves at the southern end of the lake have had a long-term concern 

regarding the effect of lowered lake levels on their freeze protection. While this 

technical question is not fully resolved, it is possible to estimate the economic 

consequences using crop insurance rates. The expected increase in crop insurance 

would be $7,900 per year. This issue is expected to become less critical as the citrus 

lands shift to urban uses. 

The flood and drought damages to the muck farms with the existing water control 

system were investigated. The results indicate that the current system provides a high 

level of protection to the farmers and so they have not suffered any substantial crop 

damages due to water problems. 

A preliminary analysis of the impact of restrictions on muck farm backpumping 

indicate that the farmers would suffer losses but not in direct proportion to the 

reduction in available land since they only use all of the available land during a few 

months of the year, and they could reschedule their farming activities to minimize these 

impacts. Unfortunately, due to lack of data, it was not possible to do a detailed analysis 

of this alternative. 
Appendix H 

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445 

Overall, the situation facing the Lake Apopka Basin is similar to problems throughout 

the country and around the world. In the United States, agricultural policies for many 

years have encouraged the development of wetland areas. During the period from the 

mid-1950s to the mid-1970s, 87% of the wetland losses in the United States were 

attributable to agricultural development. Florida is a leader in trying to reverse these 

trends by making major efforts to reverse this trend and to restore these systems. 

Johnson, W.E., and J.E. Crumpton. 1998. Lake Apopka fish population assessment. Final 

report for Contract #97W121 for St. Johns River Water Management District, Palatka, 

Fla. Florida Game and Fresh Water Fish Commission, Eustis, Fla. 

PROJECT: Fishery (LA-4-107-D) 

EXECUTIVE SUMMARY

The environmental degradation of Lake Apopka (12,400 ha) is well known. The impact 

of this degradation, in causing declines in the sport fishery of Lake Apopka, has also 

been documented. Principal point sources of nutrient loading to the lake were 

eliminated between 1977 and 1980, and agricultural discharges from farming operations 

have been reduced since 1992. The St. Johns River Water Management District, under 

the SWIM program, has begun experimental management efforts to correct the 

problems in Lake Apopka. The Florida Game and Fresh Water Fish Commission 

conducted assessments of the fish population between 1973 and 1984, and 1988–1993. 

These studies documented fish population trends and provided baseline data prior to 

the commencement of the fish population of Lake Apopka to provide the most current 

data. 

The St. Johns River Water Management District provided funding to the Florida Game 

and Fresh Water Fish Commission to assess the fish population of Lake Apopka in 1997. 

Littoral fish populations were evaluated by 0.1 hectare blocknet samples (N = 16), and 

data were proportioned by major habitat types (open/brush shoreline, 44%; cattails 

(Typha spp.), 38%; bulrush (Scirpus californicus), 5%; and grasses (Paspalum sp. and 

Panicum spp.), 3%). Littoral sport fish species were also evaluated by bimonthly 

electrofishing samples (N = 30 per sample month). Fall trawl samples were taken (N = 

50) to assess limnetic black crappie (Pomoxis nigromaculatus) and catfish populations, 

and experimental gill nets (N = 30) were fished January, March, and May 1977 to 

evaluate limnetic gizzard shad (Dorasoma cepedianum) populations. 
SWIM Plan for Lake Apopka 

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446 

Blocknet samples taken in the littoral zone of Lake Apopka in 1997 resulted in a mean 

fish biomass of 113.6 kg/ha (data were proportioned by habitat type). Six species (of 24 

collected) composed 78% of the fish biomass: bluegill (Lepomis macrochirus) (27.2%), 

black crappie (22.4%), redear sunfish (Lepomis microlophus) (8.9%), warmouth (Lepomis 

gulosus) (7.3%), Florida gar (Lepisosteus platyrhincus) (5.7%) and blue tilapia (Tilapia 

aurea) (5.5%). The proportioned mean biomass of the 1989–1991 sample period was 

226.7 kg/ha. A decrease in blue tilapia mean biomass from 61.3 kg/ha (27%) in 1989–

1991 to 6.2 kg/ha in 1997 contributed the largest proportion of the change. The mean 

biomass of dominant sport fish collected in 1997 was 37% less for black crappie (25.4 

kg/ha) when compared to 1989–1991 (40.2 kg/ha), while no difference was found for 

bluegill and redear sunfish. 

Small bluegill and threadfin shad dominated fish numbers in the littoral samples. 

Numbers of harvestable-size sport fish in littoral samples were dominated by black 

crappie (53/ha ≥ 24 cm total length (TL)), bluegill (52/ha ≥ 16 cm TL) and redear 

sunfish (20/ha ≥ 16 cm TL). Numbers of these harvestable-size species were at least 49% 

lower when compared to values from 1989–1991 for black crappie (121/ha), bluegill 

(104/ha) and redear sunfish (56/ha). The number of bluegill and redear sunfish less 

than 16 cm TL was greater in 1997. 

Largemouth bass (Micropterus salmoides) composed 16.5 kg/ha (7.3%) of the 

proportioned mean littoral biomass in 1989–1991 blocknet samples and 6.2 kg/ha (5.4%) 

in 1997 samples, a 62% reduction. Mean numbers of largemouth bass, proportioned by 

habitat type, in 1997 were: 12/ha for total bass, 2/ha for young-of-the-year bass, 9/ha 

for bass ≥ 26 cm TL and 1/ha for bass ≥ 36 cm TL. These values were lower compared to 

1989–1991 data of 20/ha for total largemouth bass, 6/ha for young-of-the-year bass, 

15/ha for bass ≥ 26 cm TL and 9/ha for bass ≥ 36 cm TL. The average electrofishing 

catch rate for largemouth bass ≥ 24 cm TL in 1997 (0.2/5 min) was also substantially 

lower compared to annual values from 1989–1992 (range = 0.4–0.5/5 min). 

Large differences were noted when littoral blocknet data were compared by habitat 

type. Total fish biomass in 1997 averaged 65.6 kg/ha in sites devoid of all vegetation, 

132.3 kg/ha in cattails, 327.2 kg/ha in bulrush, and 676.8 kg/ha in grass sites. Biomass 

of sport fish followed a similar trend among habitats. Black crappie ranged from an 

average biomass of 14.9 kg/ha in open areas to 202.5 kg/ha in grass sites; largemouth 

bass ranged from 1.0 kg/ha in open areas to 56.0 kg/ha in grass sites; bluegill ranged 

from 15.6 kg/ha in open areas to 224.6 kg/ha in grass sites; and redear sunfish ranged 

from 6.8 kg/ha in open areas to 27.5 kg/ha in grass sites. An increasing trend of 

average biomass for all four principle sport fish species in grass sites occurred from the 
Appendix H 

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447 

1973–1976 and 1989–1991 periods to 1997 (only grass bulrush sites were sampled by 

blocknet in 1973–1976). 

Trawl catches in the limnetic area of Lake Apopka were dominated by black crappie, 

white catfish (Ameiurus catus), bluegill, and brown bullhead catfish (Ameiurus 

nebulosus). Catch per trawl for total black crappie (14.5/trawl in 1997 was the lowest 

compared to samples taken 1992 (22.9/trawl) and 1993 (28.4 trawl), while the 1997 

average value for black crappie ≥ 24 cm TL (0.5/trawl) was intermediate among years. 

Low catch rates for total black crappie were attributed to a weak 1997 year class 

(crappie < 15 cm TL). White catfish catch increased from 1.9/trawl in 1992, to 6.4 trawl 

in 1993, to 12.0 trawl in 1997; surpassing values for brown bullhead catfish (7.7/trawl). 

Although 99% of the bluegill were less than 16 cm TL (modal TL = 10 cm), catch rates 

increased from 0.5/trawl in 1992, to 2.6/trawl in 1993, to 11.0/trawl in 1997. 

Past blocknet samples demonstrated that gizzard shad dominated the fish biomass in 

the limnetic area of Lake Apopka., Experimental gill nets samples taken in 1997 

produced catches of gizzard shad which composed 94% by number and 90% by weight 

of the total catch. The average catch rate of gizzard shad (25/hr) in 1997 was lower than 

any year sampled from 1989–1992 (modal rage = 31–38 cm TL). Low catch rates and 

reduced size of gizzard shad collected in experimental gill nets suggested a substantial 

impact has occurred on the population from commercial gizzard shad harvest in Lake 

Apopka. 

When compared to blocknet samples taken from 1989–1991, average total biomass and 

numbers of harvestable-size sport fish were lower or unchanged in 1997 samples. All 

parameters used to measure the largemouth bass population were lower in 1997. 

Although bluegill and redear sunfish populations were dominated by small size classes 

(as in the past), total numbers were increased in samples taken in both littoral blocknets 

and limnetic areas. A weak year class of black crappie was produced in 1997, which 

contributed to lower average total numbers sampled by blocknet and trawl. The 

average number of black crappie ≥ 24 cm TL collected in trawl samples was similar to 

past data. Although rooted aquatic vegetation constitutes less than 1% of the surface 

area of Lake Apopka, data collected from blocknet samples indicated that expansion of 

this type of habitat is vital to the sport fish population and to the ultimate goal of 

restoring the sport fishery of Lake Apopka. 

Kenney, W.F., C.L. Schelske, and A.D. Chapman. 2001. Changes in polyphosphate 

sedimentation: a response to excessive phosphorus enrichment in a hypereutrophic 

lake. Can. J. Fish. Aquat. Sci. 58(5):879–887. 
SWIM Plan for Lake Apopka 

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448 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

ABSTRACT

Historic changes in lake phosphorus (P) loading are often determined in 

paleolimnological investigations by assessing stratigraphic changes in sediment total P. 

Polyphosphate (poly-P) in sediments may provide additional information on historic 

lake trophic status, because phytoplankton store surplus P intracellularly as poly-P 

when supplies exceed growth requirements. We hypothesize that phytoplankton (i.e., 

cyanobacteria and diatoms) with stored poly-P can remain intact and viable for many 

decades after sedimentation and that sedimented poly-P is not geochemically reactive. 

We tested our hypotheses with sediment cores from Lake Apopka, Fla., USA, where P 

loading has increased ~7-fold since the 1920s and phytoplankton biomass is nitrogen 

limited owing to excessive P enrichment. We show that sedimented poly-P is mobilized 

by sample drying (i.e., becomes water soluble, geochemically reactive, and 

bioavailable); that anthropogenic P enrichment is expressed in the sediment record as 

increasing concentrations of poly-P; and that, consequently, sedimentary poly-P is a 

sensitive indicator of historic excessive P enrichment. Sedimentary poly-P is not 

geochemcially reactive; thus, it represents biological attenuation that may partially 

ameliorate the effects of excessive P loading. 

Locker, S.D., G.R. Brooks, and L.J. Doyle. 1988. Results of a seismic reflection investigation 

and hydrogeologic implications for Lake Apopka, Florida. Special Publication SJ88-SP5. 

Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Seismic Reflection Profiling (LA-1-108-D) 

CONCLUSIONS

Seismic reflection profiling in Lake Apopka provides insight to the nature of strata 

associated with the Floridan Aquifer, shallow solution features, and the character of 

near surface sediments. Interference from suspected gaseous sediments and intense 

reflections with multiples from a shallow horizon beneath lake sediments obscured 

much of the shallow portion of the seismic profiles. Additional field work involving 

sediment probing and coring is recommended to ground truth seismic interpretations 

and to provide a basis for more in-depth analyses of the seismic profiles. A sampling 

program, guided by the seismic reflection survey, would be fundamental to further 

assessment of stratigraphy and hydrogeology beneath Lake Apopka. 
Appendix H 

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The principal findings are: 

1. Two primary reflection horizons (A and B) were mapped and appear to correlate to the 

top of the Ocala Group limestone and top of a low porosity zone (dolomite zone) in the 

Avon Park Formation, respectively. These horizons are irregular and discontinuous, 

suggestive of paleokarst environments. 

2. Major structural discontinuities, such as large sinkholes, were not found on the lines 

surveyed. The primary sequences below the lake appear to be relatively flat lying, but 

modified by solution processes. However, there is no evidence of active subsidence. 

3. The structural contour map on horizon B indicates variations in the strata that closely 

correspond to the top of the Floridan aquifer. 

4. Shallow near-surface depressions are found in all areas of the lake (13% of tracklines) 

except in the central-northeast quadrant. These appear to be inherited from underlying 

Miocene to Eocene age limestone sequences. 

5. Lake sediments appear to contain various amounts of gas (probably biogenically 

derived) that probably causes a fuzzy wipe-out zone in areas of high concentrations. 

6. From the seismic reflection data we cannot be unequivocal about the hydrologic 

conditions related to exchange of water with the Floridan aquifer. However, muddy 

sediments and an underlying lithified or compact surface suggests that little exchange 

between lake water and the deeper strata (aquifer) occurs. 

A sediment probing and coring program is recommended to ground truth the seismic 

interpretations presented herein and to construct accurate stratigraphic sections for a 

more direct assessment of hydrogeology beneath Lake Apopka. 

Lowe, E.F., L.E. Battoe, D.L. Stites, and M.F. Coveney. 1992. Particulate phosphorus 

removal via wetland filtration: an examination of potential for hypertrophic lake 

restoration. Environmental Management 16(1):67–74. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 
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St. Johns River Water Management District

450 

ABSTRACT

Lake Apopka in Florida, USA, is a large (area = 124 km2), hypertrophic (mean total 

phosphorus = 0.220 g/m3; mean chlorophyll a = 60 mg/m3) lake, with a large 

sedimentary store of available P (1635 X 106 g P). Phosphorus loading from floodplain 

farms (132 X 106

 g P/yr) has been the primary cause of eutrophication. Assuming 

elimination of farm P loading, the Vollenweider model predicts a decline in equilibrium 

P concentration from 0.270 to 0.024 g/m3

, if the P sedimentation coefficient (s) remains 

constant. It is likely, however, that the value for s will fall with the elimination of farm 

loading due to unabated internal P loading from the sediments. Under a worst-case 

scenario (s = 0), the model predicts that exportation of P from the lake via wetland 

filtration will greatly accelerate the lake’s recovery. Recirculation of lake water through 

a 21-km2, created wetland and elimination of farm P loading is projected to result in a 

negative P balance for the lake (-23 X 106 g P/yr) leading to depletion of P stores in the 

lake in about 60 years. The estimated cost of the project, $20 million, is less than 3% of 

the estimated cost of dredging. A 3.65-km2 demonstration project is under way to test 

and refine the wetland filtration technique. We believe the technique could be costeffective for other hypertrophic lakes. 

Lowe, E.F., L.E. Battoe, M.F. Coveney, C.L. Schelske, K.E. Havens, E.R. Marzolf, and 

K.R. Reddy. 2001. The restoration of Lake Apopka in relation to alternative stable 

states: An alternative view to that of Bachmann et al. (1999). Hydrobiologia 448:11–

18. 

PROJECT: Restoration Monitoring (LA-6-803-S) 

ABSTRACT

Bachmann et al. (1999) postulated that wind energy initiated, and has maintained, high 

turbidity in hypertrophic (mean chlorophyll a = 92 μg l-1) Lake Apopka, Florida (mean 

depth =1.6 m; area = 12,500 ha). They asserted that the turbid condition was initiated by 

a hurricane in late 1947 that destroyed submersed plant beds and that high turbidity 

has since been maintained by wind-driven resuspension of fluid sediments. In their 

view, there has been sufficient light for re-establishment of submersed plants over 

about 38% of the lake bottom but plant growth has been precluded by the fluid 

character of the sediments. They concluded that the restoration program of the St. Johns 

River Water Management District, which includes reduction of the phosphorus (P) 

loading rate, will not restore water clarity or submersed vegetation. 
Appendix H 

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451 

An alternative explanation for Lake Apopka’s turbid state is that it was initiated, and 

has been maintained, by excessive P loading that led to algal blooms and elimination of 

submersed vegetation through light limitation. The transition to the turbid state was 

contemporaneous with drainage of 7,300 ha of the floodplain wetland to create polders 

for farming, beginning in the early 1940s. Lake P budgets indicate that drainage of the 

farms caused a seven-fold increase in the P loading rate (0.08 g TP m-2

 y-1 to 0.55 g TP m-2

y-1). Paleolimnological analysis of lake sediments also indicates an increase in the P 

loading rate in mid-century, concomitant with the decline in submersed vegetation and 

the increase in phytoplankton abundance. After the increase in P loading, wind 

disturbance may have accelerated the transition to the turbid state; but, before the 

increase in P loading, wind disturbance was insufficient to elicit the turbid state, as 

evidenced by the stability of the clear-water state in the face of 14 hurricanes and 41 

tropical storms from 1881–1946. 

Measurements of photosynthetically active radiation (PAR) indicate that light limitation 

has inhibited submersed plant growth except on the shallowest 5% of the lake bottom. 

Further, the correlation between the diffuse attenuation coefficient (KPAR) and 

chlorophyll a (CHLA) indicates that light limitation would be removed over about 82% 

of the lake bottom with a reduction in CHLA from 92 μg l-1 to 25 μg l-1. 

Recently, following a 40% reduction in the P loading rate, the mean total P (TP) 

concentration, mean CHLA, and total suspended solids fell by about 30% while mean 

Secchi depth increased by more than 20%. Submersed plant beds appeared in areas 

devoid of macrophytes for nearly 50 years. These improvements, during a period with 

no change in mean wind speeds measured at Lake Apopka, provide the strongest 

evidence that the turbid state has been maintained by excessive P loading and that the 

current restoration program, which combines P load reduction with planting and 

removal of planktivorous fish, will be effective. 

Lowe, E.F., D.L. Stites, and L.E. Battoe. 1989. Potential role of marsh creation in 

restoration of hypertrophic lakes. In Constructed wetlands for wastewater treatment: 

Municipal, industrial and agricultural, D.A. Hammer, ed., 710–717. Proceedings from 

the First International Conference on Constructed Wetlands for Wastewater 

Treatment. Chelsea, Mich.: Lewis Publishers. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

452 

INTRODUCTION

The use of wetlands to reduce concentrations of dissolved nitrogen (N) and phosphorus 

(P) in secondary sewage effluent is well documented. We propose a novel application: 

the use of wetlands for the restoration of hypertrophic lakes. In a typical sewage 

treatment wetland, water high in inorganic nutrients passes through the system once, 

and the management goal is to maximize the nutrient removal efficiency. In our 

application, water to be treated has high concentrations of nutrients associated with 

particles and dissolved organic molecules. Water is passed through the system many 

times rather than once. Goals of this approach are to maximize power (nutrient quantity 

removed per unit of time) and capacity (nutrient permanently stored) rather than 

efficiency (nutrient fraction removed in a single pass). 

DISCUSSION

The efficiency assumed above (30%) is conservative. At least 50% of the P in Lake 

Apopka’s water is associated with living algae; soluble reactive P accounts for another 

1–20%. The balance is probably associated with suspended sediments. Thus, 80% or 

more of the P is particulate and would be filtered by the wetland. Natural wetlands can 

remove 60–90% of suspended solids in wastewaters; 30% removal is below the 

minimum expected efficiency (60% efficiency x 80% particulate P = 48% removal). In 

addition, some soluble P would be expected to be transformed and stored in soil and in 

plant biomass. South Florida wetlands receiving agricultural wastewater high in soluble 

reactive P (SRP = 58–67% of total P) removed a minimum of 26% of the P and averaged 

55% removal. 

Although treatment efficiency must be considered, the primary concern in the proposed 

system is the amount of nutrient that could be removed annually rather than removal 

efficiency. As P loading increases, P removal efficiency decreases asymptotically, but 

the power of nutrient removal increases (Figure 3). For example, at 0.85 m3

/s, the areal 

loading rate would be 0.18 g/m2

/yr, the removal efficiency would be about 90%, and 

the power of nutrient removal would be 5 metric tons. At 14.4 m3/s, the areal loading 

rate would be 3.1 g P/m2

/yr and the removal efficiency would fall to 50%, but 50 metric 

tons would be removed (a 10-fold increase in power). 

Maximum power would be attained at a relatively low efficiency. We believe, however, 

that the complete efficiency curve is sigmoidal (Figure 3). We expect rapidly declining 

efficiency at high hydraulic loading due to low retention time and high current velocity. 

Power would also drop precipitously at these levels. 
Appendix H 

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453 

Wetland creation could be appropriate for restoration of many other hypertrophic lakes. 

In any application, water must be moved against a hydraulic gradient; thus, economic 

constraints will always apply. The realized power of nutrient removal will most likely 

be determined by the cost of moving water. In large-scale applications, funding may 

limit power to a level well below the maximum. Lake Apopka should provide a useful 

example of the efficacy of wetland creation in hypertrophic lake restoration. 

Lowe, E.F., L.E. Battoe, M. Coveney, D. Stites. 1999. Setting water quality goals for 

restoration of Lake Apopka: Inferring past conditions. Lake Reserv. Manage.

15(2):103–120. 

PROJECT: Implementation of Restoration and Management Techniques (LA-6-802-S) 

ABSTRACT

Lake Apopka is a large (12,500 ha), hypereutrophic lake in central Florida which is the 

subject of a state-sponsored restoration program. We used three quantitative methods 

in concert with an analysis of the history and general character of the lake and drainage 

basin to infer the past conditions. We specifically examined two past conditions: (1) 

pristine (before any major anthropogenic disturbance) and (2) antecedent (before a 

specific, major anthropogenic disturbance). For Lake Apopka the pristine condition 

ended in the 1890s when a canal was dug which lowered the elevation for surface water 

outflow. The antecedent condition ended in the late 1940s when most of the lake’s 8,900 

ha of floodplain marsh was drained for farming. History, general lake and basin 

characteristics, and the quantitative analysis indicate that Lake Apopka was 

mesotrophic; with clear-water and native, submersed macrophyte beds; in both the 

pristine and antecedent conditions. The three quantitative (reference lakes, empirical 

models, and a loading model) were used to infer the ranges of most probable values in 

the antecedent condition for total phosphorus, chlorophyll a and Secchi depth. These 

ranges were 32–51 mg/m3

 for total phosphorus, 8–38 mg/m3 for chlorophyll a, and 

1.39–0.76 m for Secchi depth. Lake Apopka has had a history strikingly similar to that 

described for Dutch lakes affected by cultural eutrophication with proliferation of 

macrophytes in the clearwater state preceding a rapid transition to the turbid, algaldominated state induced by a large increase in the phosphorus loading rate. 

Newman, S., and K.R. Reddy. 1993. Alkaline phosphatase activity in the sediment-water 

column of a hypereutrophic lake. J. Environ. Qual. 22(4):832–838. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

454 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

ABSTRACT

Inorganic P limitation in many aquatic systems may be overcome through the 

enzymatic hydrolysis of organic P compounds. The objective of our study was to 

determine the effect of dissolved oxygen (DO) of the water column and redox (Eh) 

status of the sediments on alkaline phosphatase activity (APA) in a shallow 

hypereutrophic lake, Lake Apopka, located in central Florida. Alkaline phosphatase 

activity was used as an index of potential organic P mineralization. Lake water 

incubated in the dark under aerobic and anaerobic conditions for 24 h. Under aerobic 

conditions, APA increased from 22 to 43 nM min-1 within 24 h. Under anaerobic 

conditions, no significant change in APA was observed. Neither total soluble P nor 

soluble-reactive P exhibited significant responses to anoxic conditions in the water 

column. The increase in APA observed under aerobic conditions was attributed to 

increased plankton metabolic P demand following depletion of internal cell P. 

Sediments were incubated under six different Eh levels for 30 d. In combination with 

APA measurements, sediment organic P was fractionated into labile and nonlabile 

pools using selected inorganic chemical extractants. Phosphatase hydrolysis activity 

was positively related to pE + pH (r = -0.81), and humic acid P (r = -0.74). The results of 

this study suggest that short-term depletion of DO will not affect the enzymatic 

breakdown of organic P within the water column. Significant reduction in the alkaline 

phosphatase-dependent hydrolysis of sedimentary organic P will occur under anaerobic 

conditions; hence, P cycling in highly organic sediments may be severely inhibited. 

Olila, O.G., and K.R. Reddy. 1995. Influence of pH on phosphorus retention in oxidized 

lake sediments. Soil Sci. Soc. Am. J. 59:946–959. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

ABSTRACT

Diel pH changes in lake waters resulting from high photosynthetic activity may 

regulate water-soluble P concentration (WSP) and P sorption by suspended sediments 

in shallow eutrophic lakes. Laboratory studies were conducted to determine the pH 

effect on P fractions and P sorption kinetics in oxidized sediment suspensions from two 

subtropical lakes (Lake Apopka and Lake Okeechobee, Florida). The P sorption rate was 

calculated for sediment suspensions adjusted to various pH levels: 6.5, 7.0, 8.5, 9.5, and 

10.5 for Lake Apopka and 6.5, 7.0, 8.5, 9.5, and 10.5 for Lake Okeechobee. A decrease in 
Appendix H 

St. Johns River Water Management District

455 

pH increased the WSP concentrations in Lake Apopka sediment suspensions but had no 

effect on WSP concentrations in Lake Okeechobee sediment suspensions. Lake Apopka 

sediment suspensions at pH 7.0 (ambient) and below did not show net P uptake. 

Phosphorus uptake for Lake Apopka occurred only when pH was increased to ±8.5 and 

when P treatments were increased to ±27 mmol P kg–1, which resulted in 

supersaturation with respect to octacalcium phosphate. Phosphate solubility diagrams 

and mineral equilibria calculations suggest that P uptake by Lake Apopka sediment 

suspensions at pH ±8.5 was due to P coprecipitation with CaCO3 and probable 

formation of nonapatitic Ca-P compounds. Phosphorus sorption on Lake Okeechobee 

sediment suspensions followed first-order kinetics for all pH levels studied, with rate 

constants (k) ranging from 0.003 to 0.75 h-1. High P uptake by Lake Okeechobee 

sediment suspensions could be attributed to two reactive components: (i) amorphous or 

poorly crystalline Fe and Al oxyhydroxides at pH <7.5, and (ii) Ca/Mg carbonates and 

other minerals at pH ±7.5. 

Olila, O.G., K.R. Reddy, and D.L. Stites. 1996. Influence of drying on phosphorus forms 

and stability in the Lake Apopka Marsh. Final report submitted to St. Johns River 

Water Management District, Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

Our earlier studies showed that floc sediments in the Lake Apopka Marsh 

Demonstration Project are highly P reactive and have relatively high P retention 

capacities (Olila and Reddy 1995). However, we have limited information on the 

stability of P assimilated by these floc materials under various physico-chemical 

conditions, i.e., changes in water level, hydroperiod, redox potential, pH, and others. 

This study was conducted to evaluate the changes in P forms and distribution and 

measure P flux from the floc layer after sediment consolidation for different lengths of 

time. Increases in P flux during reflooding of a previously drawn down marsh is a 

significant issue in management, especially in constructed wetlands designed for P 

removal. In the case of Lake Apopka marsh flow-way, drawdown and sediment 

consolidation is an important part in building up the soil. Should sediment drying be a 

necessary practice in managing this marsh, there is a need to study the influence of 

drawdown and sediment consolidation on P release and stability. This research was 

conducted with the following objectives: (i) to evaluate the effects of drying periods on 

soluble reactive P and (ii) to determine the influence of drying and reflooding on P 

forms and distribution. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

456 

Results obtained from this study will provide information on the influence of drying 

time on P flux into water column. Additional information on feasible minerals or 

compounds which may control P solubility will be evaluated. 

Olila, O.G., K.R. Reddy, and D.L. Stites. 1997. Influence of draining on soil phosphorus 

forms and distribution in a constructed wetland. Ecological Engineering 9:157–169. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

ABSTRACT

Seasonal water-table fluctuations in wetlands can result in flooded and drained 

conditions in the surface soil. In constructed wetlands, water level drawdown and soil 

drainage are used in management to consolidate detrital materials, accelerate soil 

buildup, and provide easy access for other management operations. A greenhouse 

study was conducted using intact peat soil cores to evaluate the changes in bioavailable 

P and other fractions following draining and reflooding. Measurements of floodwater 

dissolved reactive P (DRP) indicated that draining and soil exposure could result in 

large P flux to the overlying water column. Phosphorus flux in soils drained for 6 weeks 

was 10-fold higher (334 mg P m-2 day–1) than in soils drained for 3 weeks (33 mg P m-2

day–1). Soil exposure also resulted in an increase in bioavailable inorganic P (estimated 

by KCl extraction) at the expense of labile organic P pool. The KCl-P pool, which was 

initially less than 2% of total P (TP), increased to 3% and 13% of TP after 3 and 6 weeks 

draining, respectively. Results suggest that various soil P fractions, particularly those in 

newly accreted materials, were highly unstable and could be released in a more 

available form when newly accreted soils undergo drying. Water level drawdown and 

reflooding could result in significant P release, a possible stimulation of algal blooms 

and other water quality problems. Therefore, soil characteristics and chemistry and 

their impact on water quality should be a major consideration when one adopts the 

flood-drain technique in wetland management. 

Parsons Engineering Science, Inc., and GeoSyntec Consultants, Inc. 2000. Review of 

documentation for the location and remediation of possible pesticide/chemical 

sites at the North Shore Restoration Area, Lake Apopka, Florida. Winter Park, Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 
Appendix H 

St. Johns River Water Management District

457 

INTRODUCTION

Parsons Engineering Science, Inc. (Parsons ES) and GeoSyntec Consultants Inc. 

(GeoSyntec) were contacted by the St. Johns River Water Management District 

(SJRWMD or the District) to assist SJRWMD with conducting a third-party review of 

environmental site assessment (ESA) and remediation reports developed by others for 

portions of the Lake Apopka North Shore Restoration Area (NSRA). The area addressed 

in this review is shown in Figure 1. The review was undertaken in an effort to help 

identify potential contamination sources which may have contributed to the recent bird 

mortalities associated with property within the NSRA. 

Lake Apopka Restoration and the NSRA 

Farm pollution must be greatly reduced for successful, permanent restoration of Lake 

Apopka. The Florida Legislature directed that this be accomplished through acquisition 

and restoration of the floodplain farms and through development of a water reuse and 

treatment facility for any remaining agriculture. 

According to information provided by the District, purchase of the 3,000-acre Duda 

property completed in 1997 and purchase of essentially all parcels in the 6,000-acre 

Zellwood Drainage and Water Control District (ZDWCD) Unit 2 area was completed in 

1998. Both areas are enrolled in the Federal Wetlands Reserve Program (WRP) of the 

Natural Resources Conservation Service (NRCS) and make up the active part of the 

NSRA at Lake Apopka. District holdings in the former Zellwin Sand Farm and in 

ZDWCD Unit 1 are not currently undergoing restoration. Final negotiations to complete 

the buy-out of all agricultural lands on the former floodplain are under way as of the 

writing of this report. 

Environmental Audits and Environmental Risk Assessment 

Phase I environmental site assessments on all properties in the NSRA were performed 

in accordance with the District’s Phase I ESA standard (Attachment I), which 

incorporates guidance contained within ASTM Standard E1527. A total of 11 properties 

were audited, although not all of these are part of the currently active restoration 

project (9,000 acres). Based on Phase I ESA findings, further Phase II ESAs, Phase III 

remediation plans, and/or Phase IV remediation action reports were done for each 

property as required. 

The Phase I ESAs as listed by the District located seven airstrips, 17 pesticide mix/load 

sites 19 pesticide storage areas, 67 petroleum storage sites, 27 equipment maintenance 

shops, 21 solid waste sites, and one wastewater treatment plant. Of the 178 potential 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

458 

environmental concerns that were noted, 79 were verified in Phase II. Phases III and IV 

remediation included the removal of 20,343 tons of soil (about 10,000 tons containing 

pesticide contaminants) and 3,230 gallons of groundwater. Some 400 soil samples were 

analyzed for pesticide residues in the environmental assessments and in follow-up 

sampling. 

The Phase I through Phase IV ESAs were performed on a series of agricultural 

properties previously owned by various farmers. The land on which the farms were 

developed formerly was part of the lakebed of Lake Apopka. Beginning in the 1940s, 

the land was drained and a water management system consisting of a series of dikes 

and canals was installed to accommodate agriculture. Long-term intensive agricultural 

practices had adversely impacted Lake Apopka and surrounding lands. To eliminate 

the negative impacts of the farms the Legislature mandated and funded the buyout of 

the farms. A series of ESA investigations and remedial actions were undertaken to 

minimize environmentally impacted site “hot spots” within the NSRA area. Upon 

completion of these efforts, portions of the NSRA were flooded in 1998. Upon the 

discovery of a series of bird mortalities, the NSRA was subsequently drained to 

minimize additional potential ecological impacts. 

Parsons ES and GeoSyntec evaluated documents provided by SJRWMD to identify 

areas of environmental concern (AEC) that could need further evaluation to assist the 

District in determining if any of the AECs have the potential to be contributing to the 

bird mortality problem referenced above. The reviewed environmental documents 

consist of Phase I through Phase IV ESA reports generated as part of the District’s 

legislatively mandated acquisition of the farms within the historic Lake Apopka 

floodplain. A Phase I ESA typically consists of noninvasive investigations such as visual 

site inspection, public records review, and interviews with knowledgeable parties, etc. 

undertaken to determine if regulated materials or conditions capable of adversely 

impacting the site’s environment have been released. A Phase II ESA typically consists 

of invasive investigations (such as sampling), undertaken to confirm potential impacts 

based on areas of concern identified in the Phase I investigation. A Phase III ESA is 

conducted to delineate the extent of contamination in impacted site media (soil, 

sediment, surface water and groundwater) and to propose plans for remedial activity, 

and a Phase IV ESA summarizes the remedial activities and the confirmation sampling 

results. 

Specifically, the Parsons/Geosyntec document reviews were conducted to assist 

SJRWMD in locating possible chlorinated pesticide or other chemical contamination 

“hot spot” sites remaining in the area that could contribute to ecological impacts and 

may require further evaluation and/or remediation. Identified contamination contained 

within the document set provided by the District was evaluated in the course of the 
Appendix H 

St. Johns River Water Management District

459 

review, including contamination resulting from compounds which may not be 

specifically identified as acutely toxic to site wildlife. In order to maintain objectivity 

and focus, the SJRWMD limited the review to the documents they provided. A list of 

the documents provided appears in Table 1. The specific objectives of this review were 

as follows: 

• Evaluate the procedures, including ASTM-E1527-97, used to identify AECs. 

• Consider the appropriateness of the rationale used to draw conclusions and address 

the identified AECs. 

• Identify AECs not identified in previous assessment work. 

• Evaluate the analytical methods utilized and the appropriateness of the chemicals of 

potential concern. 

• Develop recommendations for each AEC, as needed. 

Percival, H.G. 1994. Lake Apopka’s alligators: The end of the ruling reptiles? Lake 

Reserv. Manage. 9(2):102. 

PROJECT: Fishery (LA-4-107-D) 

ABSTRACT

Current alligator (Alligator mississippiensis) density on Lake Apopka is about 10% of that 

observed prior to 1980; furthermore, it is about 50% of densities in other comparable 

Florida wetlands. This is due largely to reduced egg viability rates, which on Apopka 

are about 20% (as opposed to about 50% on six other study areas). As part of a multidisciplinary team, we investigated influence of microhabitat, clutch temperature, and 

nesting material on viability, and we compared the effects of these factors across six 

other Florida wetlands. These characteristics do not explain the reduction in Apopka’s 

egg viability. We tentatively hypothesize that chlorinated hydrocarbon pesticides have 

reduced the reproductive potential of Apopka’s alligators, and we speculate that the 

situation on Apopka is only the most extreme manifestation of a problem that could be 

more widespread throughout central Florida. The preface to solving water-resource 

problems is understanding them. Causal chains in potential contaminant situations can 

be particularly difficult to trace, and we found that addressing the Apopka problem 

required a diverse research/management team. We suspect that such teams may 

become increasingly important for tackling some lake management issues. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

460 

Pollman, C.D., D.A. Graetz, F.V. Ramsey, K.R. Reddy, and T.J. Sullivan. 1988. Feasibility 

of sediment removal and reuse for the restoration of Lake Apopka. Special Publication 

SJ88-SP10. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Sediment Recycling (LA-4-204-F) 

EXECUTIVE SUMMARY

Lake Apopka forms the headwaters of the Oklawaha Chain of Lakes, a eutrophic to 

hypereutrophic chain of lakes located in central Florida approximately 25 km northwest 

of Orlando. Once a popular resort area noted for its game fishing, Lake Apopka is now 

ranked as the 17th most eutrophic lake in Florida, largely because of poor sewage 

treatment practices adopted by the City of Winter Garden and direct backpumping of 

nutrient-enriched irrigation water into Lake Apopka and the Apopka-Beauclair Canal 

from low-lying muck farms on the northern shores of the lake. Sewage discharges from 

Winter Garden on the south shore of Lake Apopka began ca. 1922–1927, followed by 

muck farm discharges starting in 1942. Although in all likelihood Lake Apopka has 

always been quite productive, primary productivity historically was dominated by 

dense stands of macrophytes. Despite high rates of external nutrient inputs, 

macrophytes continued to dominate until 1947, when hurricanes destroyed large 

amounts of the bottom vegetation. Opportunistic algal blooms appeared almost 

immediately and have persisted unabated through the present. 

In 1979, the U.S. Environmental Protection Agency (EPA) published a final 

environmental impact statement (EIS) on the restoration of Lake Apopka. The final EIS 

recommended a phased restoration program consisting of short- and long-term 

objectives. Short-term objectives included continued monitoring of in-lake water quality 

and a demonstration project to examine lake drawdown as a restorative measure; longterm objectives included “continued evaluation of restoration alternatives and methods 

which would address the lake’s internal loading problem.” The efficacy of the most 

promising technique, lake drawdown, was acknowledged to be uncertain and, should 

drawdown prove infeasible, EPA suggested that “the possibility of dredging the lake 

and marketing the muck should be pursued.” 

The St. Johns River Water Management District (SJRWMD) has been charged by the 

State of Florida legislature to assess the feasibility of restoring Lake Apopka to Class III 

water quality standards (Chapter 17-3, F.A.C.). As part of this legislative mandate, this 

study revisits the feasibility of dredging Lake Apopka. The economics of sediment 

reuse, which previously had not been analyzed, are examined in conjunction with 

recent data on sediment physical and chemical characteristics to develop a cost benefit 

analysis of dredging, coupled with sediment reuse to restore Lake Apopka to a less-
Appendix H 

St. Johns River Water Management District

461 

enriched, more beneficial trophic state. Because of the uncertain economics of sediment 

reuse specific for Lake Apopka sediments, the objectives of this study were thus 

twofold: 

1. Evaluate via the existing literature the feasibility of sediment removal as a means to 

restore Lake Apopka, using documented case studies of other systems as models in 

conjunction with extant data for Lake Apopka to assess the effects on surface chemistry 

of the lake 

2. Evaluate the market potential for recovered sediment and develop a cost/benefit 

analysis for using sediment removal to restore Lake Apopka 

Dredging has been used with varying degrees of success to restore a number of lakes in 

North America and Scandinavia. To a very large degree, the success of dredging relates 

to the adequacy of pre-dredging studies to define the magnitude of the problem. 

Dredging is generally most feasible in small lakes with organically rich sediment, low 

sedimentation rates, and long hydraulic residence times. Large lakes have been 

dredged, but economics become increasingly important as lake surface area increases. 

Cost increases in larger lakes are non-linear, reflecting not just concomitant increases in 

material to be removed in larger lakes but also increased pumping costs as a result of 

increased pumping distance (reflecting head losses due to friction in the pipe 

conducting dredged material onshore) across larger lakes. The largest lake dredged to 

date is Vancouver Lake, Washington (1,052 ha). By comparison, Lake Apopka is nearly 

12 times larger (surface area = 12,400 ha). 

Problems inherent in dredging as a general technique include short-term pulses of 

nutrient release and liberation of toxic materials (e.g., trace elements and organic 

pesticides) due to sediment resuspension, oxygen depletion, and potential effects to 

fisheries, wildlife, and benthic fauna. Other issues concern the ultimate use and stability 

of dredged material, as well as the treatment and disposal of nutrient-enriched 

supernatant from dewatered sediments. Pumping costs clearly indicate the need to 

dispose of dredge spoils near the lake. Finally, the overall efficacy of dredging is still in 

question despite the number of lakes, which have been dredged; documentation of post 

dredging effects on lake restoration has been characteristically poor, largely because of 

limited resources. 

Lake Apopka sediments generally consist of a relatively uniform, organic, flocculent 

material underlain by mostly peaty deposits. In 1987, the organic floc averaged 117 cm 

depth compared to 80 cm in 1968. Interstitial nutrient concentrations in the floc exceed 

water column concentrations by over an order of magnitude, and resuspension of this 

easily disturbed material is believed to be a major contributor to sustained, high rates of 

algal productivity in the lake. One major area of uncertainty regarding the effectiveness 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

462 

of the dredging in Lake Apopka is the internal loading characteristics of the underlying 

peat once it is exposed to the water column by dredging. Interstitial concentrations in 

the peat also are quite high, and the dynamics of nutrient transport across an oxic peatwater interface are unknown. The peat is believed to be physically more stable than the 

surficial floc, and resuspension effects on nutrient release in all likelihood would be 

reduced significantly. 

Dredging costs for Lake Apopka were based on removing as much of the sediment floc 

layer as practicable. A 24-inch is the largest dredge which could operate reasonably in 

Lake Apopka; with this size dredge, only sediments under the 1.2 m contour would be 

removed. Under these operating constraints, approximately 10,400 ha would be 

dredged, giving a total volume of 121.76 x 106 m3

 of sediment to be removed. With five 

24-inch dredges operating, dredging of Lake Apopka could be accomplished in 5.9 

years. Total dredging costs, exclusive of (1) spoil area land acquisition and clearing 

costs and (2) upland acquisition costs for storage of dried sediment prior to reuse or 

sale, total $868,800,000. 

Sediment reuse offers only limited ability to recover dredging costs. Approximately 1.43 

x 106

 metric tons of dried sediment will be removed from Lake Apopka during each 

year of dredging. The total value of this material as fertilizer approximates $55,000,000; 

use as a soil amendment has an estimated yield of $25,000,000 to $50,000,000. An upper 

limit on the economic reuse value of dried Lake Apopka sediment is $97,400,000; this 

estimate is based on using Lake Apopka sediment as a growth medium for the 

ornamental horticulture industry and assumes that the dried sediment has the same 

value as peat. In all likelihood, the dried sediment will not have the same bulk texture 

characteristics as peat, and its direct usefulness to the ornamental horticulture industry 

will be limited. With a 20% mix on Lake Apopka sediment in the growth medium, the 

current market for Florida peat would yield an estimated $3,200,000 annual return on 

Lake Apopka sediment reuse. The option of using Lake Apopka sediment as a potting 

or growth medium for the ornamental horticulture industry thus defines the minimum

cost for dredging: $771,400,000, which assumes that the upper limit market value of 

$97,400,000 from use as a potting medium can be realized. Project costs almost certainly 

will be closer to between $814,000,000 and $844,000,000. 

A number of assumptions were made in the cost/benefit analysis that should be 

examined in more detail before further consideration is given to dredging of Lake 

Apopka. Uncertainties lie in three main areas: (1) engineering aspects of dredging, (2) 

sediment reuse, and (3) internal loading aspects of the remaining peat sediments after 

the unconsolidated floc (UCF) and consolidated floc (CF) sediments have been 

removed. One major uncertainty considers redistribution of UCF and CF sediments 

from undredged areas into dredged areas. Over the relatively long span of the project 
Appendix H 

St. Johns River Water Management District

463 

(5.9 years), redistribution is very likely and may negate much of the perceived benefits 

of dredging. Moreover, only 84% of Lake Apopka can be dredged with a 24 inch 

dredge, and some of the nearshore sediments will redistribute into the open lake after 

dredging has been completed. Other studies need to be conducted on the drying and 

handling characteristics of dried Lake Apopka sediment as well as determining its 

effects on plant growth before the economic value of Lake Apopka sediments can be 

firmly established. These studies are useful for developing more realistic reuse cost 

benefits; nonetheless, the upper limit market value of $97,400,000 will not increase 

whatever the outcome of these studies. 

Reddy, K.R., G. Bao, O.G. Olila, and D.L. Stites. 1998 (draft). Effects of chemical 

amendments on marsh soil chemistry and nutrient flux. Final report for Contract 

96W258, submitted to St. Johns River Water Management District, Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

INTRODUCTION

The St. Johns River Water Management District is purchasing muck farm lands for 

wetland restoration as part of District aquatic ecosystem restoration programs. The 

initial flooding for the re-conversion of these fields to wetlands often results in the 

release of large amounts of soil-bound (porewater) phosphorus. The high P flux after 

initial flooding may result in the discharge to the adjacent water bodies of water with 

high phosphorus concentration and potentially exceed the loading limits for the 

wetland areas. It may also result in conditions conducive to the development and 

maintenance of low diversity wetlands that slow succession to more desirable high 

diversity vegetation communities and animal habitats. 

One of the promising solutions of the initial nutrient flushing problem is the use of 

chemical amendments in immobilizing or inactivating P before it enters the water 

column. This approach has been reported as a sound management technique in lakes 

but has not been evaluated for wetlands. Laboratory studies showed that a number of 

chemical amendments are effective in wetlands (Ann et al. 1998). This study was 

conducted to evaluate the effectiveness of a few selected compounds under field 

conditions. The objectives of this study were to determine the influence of selected 

chemical amendments on (i) changes in physico-chemical properties of soils resulting 

from chemical amendments, (ii) dissolved nutrient concentrations of soil porewater, 

and resulting P flux, and (iii) effectiveness of reducing or minimizing nutrient 

(particularly P) flux during initial flooding of a previously farmed organic soil. The 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

464 

study results will be used in conjunction with water quality data collected and analyzed 

by the St. Johns River Water Management District to identify any soil amendments that 

could effectively reduce or minimize nutrient (particularly P) flux during initial 

flooding of a previously farmed organic soil. 

Reddy, K.R., W.F. DeBusk, and D.A. Graetz. 1991. Nutrient dynamics in recreated marshes 

adjacent to Lake Apopka. Research program manual. Submitted to St. Johns River 

Water Management District, Palatka, Fla. IFAS, University of Florida, Gainesville. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

INTRODUCTION

Several studies (Boyt et al. 1977; Fetter et al. 1978; Turner et al. 1976; Reddy et al. 1982; see 

review by Richardson and Davis 1987) have reported the use of freshwater wetlands 

(swamps and marshes) and other flooded soil systems as a possible means of reducing N 

and P levels of waste waters. This concept is also being evaluated as a mechanism to 

improve water quality in Lake Apopka. The lake water will flow through a constructed 

marsh allowing settlement of algal biomass and other detrital materials on the soil surface. 

The water will then be returned to the lake, presumably with considerable improvement 

in quality. By recycling the lake water through the wetlands, significant amounts of N and 

P should be removed form the lake basin with a resultant improvement in water quality in 

the lake. 

In order to maximize the N and P removal rate as well as the net storage capacity of the 

wetlands, it is important to understand the biogeochemical processes responsible for 

nutrient removal. Flooded organic soil chemistry is very complex because of the 

interactions between organic and inorganic forms of nutrients and associated chemical 

and biological components. The degree of reduction in flooded organic soils can have a 

significant impact on labile and non-labile pools of C, N and P, and ultimately their 

retention/release by these soils. Although these mechanisms have been documented for 

many mineral flooded soils, very little or no information is available for flooded organic 

soils. 

Nitrogen and P removal in these systems primarily occurs through physical, chemical, 

and biological processes in the floodwater and sediment. A significant portion of 

floodwater and porewater N and P can also be removed through uptake by 

macrophytes and algae. Rate of N and P removal by these processes in influenced by 

the physico-chemical conditions that exist in the floodwater and in the sediment. Some 
Appendix H 

St. Johns River Water Management District

465 

of these conditions are (1) dissolved O2 in the water; (2) pH; (3) temperature; (4) 

residence time of water; (5) water depth; (6) mixing in the water column; and (7) 

presence of aquatic macrophytes and algae. In addition, underlying sediments can 

function as a sink or source of N and P to the floodwater. This depends on the 

interstitial N and P concentration in the sediments, and N and P regeneration rates in 

the sediments. 

Many wetlands are effective in the removal of inorganic forms of N and P, but are poor 

sinks for organic forms of N and P, but are poor sinks for organic forms of N and P. 

Studies by Kadlec and Tilton (1978), Small (1978), Toth (1972), and Boyt et al. (1977) 

showed a P reduction of 95–98% when freshwater swamp and marsh systems were 

used to treat waste water effluents containing between 3 and 11 mg P L-1, while smaller 

reductions of 16–60% have been reported for wetlands or flooded fields receiving 

drainage water containing P concentrations of ± mg L-1 (Bentley 1969; Federico et al. 

1978; and Reddy et al. 1982). Depending on soil conditions and P loading, the efficiency 

of flooded organic soils can decrease from 90% of P removal to less than 30% within a 

few years (Richardson and Davis 1987). 

In a laboratory study, Reddy (1983) noted that N removal rates from floodwater were 

controlled by the initial floodwater NH4

+

 and NO3

-

 concentration rate of NH4

+

 diffusion 

from the sediments to the overlying water, ammonification in the sediments, NH3

+

volatilization and nitrification at the sediment-water interface, and denitrification in the 

sediments. Under the conditions studied, NH4

+ concentrations of the floodwater were in 

the range of 0.01–0.05 μg mL-1, while NO3

-

 concentrations were in the range of 0.27–0.78 

μg mL-1. Sediments with organic matter were found to be less effective in the removal of 

floodwater organic N, C and P than the sediments with calcareous clay loam. 

The amount of soluble P released into floodwaters of flooded soils, lake sediments, and 

swamp and marsh sediments depends on the capacity of the soil or sediment to desorb 

or adsorb from solution, mineralization rate of organic P, and diffusion rate of P from 

the sediment to the overlying waters. These processes play a role in determining 

whether the P concentration in the interstitial and overlying water is adequate for the 

nutritional requirements of plants and aquatic organisms, and whether these systems 

can be used for removing P from the overlying waters. Inorganic P exchange rates were 

found to be dependent on the capacity of the sediment to adsorb or desorb P (Reddy 

1983). Total P exchange rates were in the range of –1.04 to 0.34 mg P m-2 day-1

. 

For organic soils obtained from Lake Apopka drainage basin (Reddy and Rao 1983), 

ammonification occurred at a rate of 110 mg N m-2 day-1, and NH4

+

 flux from the 

anaerobic soil layer to the floodwater and aerobic soil layer was 45 mg N m-2 day-1. The 

sequential N processes occurring in a flooded organic soil include: ammonification in 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

466 

the anaerobic soil layer, upward diffusion of NH4

+

 from the anaerobic soil layer to the 

floodwater, nitrification in the floodwater, downward diffusion into the anaerobic soil 

layer and denitrification in the anaerobic soil layer. Loss of N due to these processes 

represented about 35% of the mineralized NH4-N in the 21-cm organic soil column. 

Results also showed that ammonification and NH4

+

 diffusion probably are the ratelimiting processes in N loss from a flooded organic soil. 

The same study (Reddy and Rao 1983) showed that the rate of soluble P production in 

the anaerobic soil layer was 16 mg P m-2 day-1. Major processes occurring in the 

anaerobic layer were mineralization of organic P, adsorption-desorption of P, and 

diffusion from sediment to the overlying water. Losses of P due to these processes 

represented about 53% of the solubilized P in the 21-cm organic soil column. Flux 

measured in this study were significantly higher than those presented in an earlier 

study by Reddy (1983), reflecting differences in floodwater retention time, and initial P 

concentrations of the floodwater. 

Increase in P solubility in flooded mineral soil usually has been attributed to the 

reduction of ferric oxyhydroxide and ferric phosphate compounds to more soluble Fe2+

forms and to the hydrolysis of P compounds. Increased P release in flooded organic 

soils is probably due to the solubilization of Fe, Al, and Ca-P. Wetlands high in mineral 

matter were shown to retain more P than swamps low in iron and aluminum 

(Richardson 1985). In alkaline mineral soils, increase in available P was not due to soil 

reduction of ferric phosphate, but rather to increased soil water content. Reasons for not 

detecting an increase in available P as the alkaline soils were reduced were due to (1) 

lack of reductant soluble P, and (2) control of soluble P by the calcium system. Upon 

flooding, organic soils undergo reduction much more rapidly than mineral soils, with 

redox potential (Eh) values of <-200 mV occurring within a few days after flooding. 

Initial slow reduction is due to the buffering of capacity of nitrate, since many organic 

soils have a large accumulation of nitrate under aerobic conditions. These initially high 

Eh values can have a significant impact on P solubility in flooded organic soils. 

The sulfate concentration of Lake Apopka water is in the range of 20–30 mg L-1. 

Continuous inputs of sulfate to a constructed marsh can have a significant impact on 

organic matter decomposition during sulfate respiration (Howarth and Teal 1979). At 

this time, no information is available on the significance of sulfate reduction in Florida’s 

wetlands. 

The background information presented above discusses some of the significant 

biogeochemical processes occurring in flooded soils. Although the soil processes are 

important in controlling efficiency of a constructed marsh, the reactions occurring at the 

root-soil interface also play a significant role in C, N and P dynamics of a wetland. For 
Appendix H 

St. Johns River Water Management District

467 

example, oxygen transport by wetlands plants can play a significant role in 

decomposition of organic matter and N losses as a result of nitrification-denitrification 

reactions (Reddy et al 1989). 

The environmental quality of the Oklawaha Chain of Lakes (Fig. 1) has been a subject of 

concern for various state agencies, local agencies, and private citizens for more than 20 

years. Progressive eutrophication has greatly reduced or eliminated many of the 

recreational and water quality values of the lakes. Lake Apopka, the first and largest of 

the chain of lakes, is also the most severely degraded. 

In recognition of the problems and potential values of Lake Apopka, the Florida 

Legislature in 1985 passed Chapter 85-148, Laws of Florida, which funded studies 

aimed at determining feasible means for restoring the lake. The effort was furthered by 

the Surface Water Improvement and Management Act of 1987 (Chapter 87-97, Laws of 

Florida), which identified Lake Apopka as a priority water body in need of restoration 

studies. Since enactment of that legislation, diagnostic and feasibility studies have 

resulted in the development of the Lake Apopka Marsh Flow-Way, a project designed 

to restore Lake Apopka by marsh filtration of nutrient-laden lake water. 

The purpose of the Marsh Flow-Way Demonstration Project (Fig. 2) is to acquire the 

knowledge and experience necessary to effectively design and manage the projected 

full-scale marsh flow-way for lake restoration. In order to optimize marsh management 

for cost-effective nutrient removal, it is necessary to understand the fate of nutrients 

that enter the marsh. The Nutrient Storage and Movement Project is designed to 

measure the major nutrient components in the marsh soil and vegetation, determine the 

rate of transformation of nutrients to and from the soil, water column and vegetation, 

and estimate the nutrient retention capacity of the system. 

OBJECTIVES

The overall objective of the proposed research is to develop a fundamental 

understanding of the biogeochemistry of C, N, P and S in flooded organic soils of the 

proposed constructed marsh adjacent to Lake Apopka. The specific objectives are to (1) 

characterize organic and inorganic forms of soil C, N and P to determine the labile and 

non-labile pools through chemical fractionation, (2) determine nutrient retention 

characteristics of organic soils and the factors regulating C, N, P and S retention or 

release, (3) determine the C, N and P exchange between the sediment and overlying 

water column, (4) determine the nutrient storage/release capacity of aquatic vegetation, 

and (5) assess the interaction of soil properties and water management with C, N and P 

retention. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

468 

Reddy, K.R., M.M. Fisher, and D. Ivanoff. 1996. Resuspension and diffusive flux of 

nitrogen and phosphorus in a hypereutrophic lake. J. Environ. Qual. 25:363–371. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

ABSTRACT

Bottom sediments in shallow lakes can play a major role in releasing nutrients to the 

overlying water column during wind induced sediment resuspension or by constant 

flux due to diffusion. Internal nutrient loads due to these processes may be equal to or 

higher than external loads. Laboratory and field experiments were conducted on Lake 

Apopka, a shallow, hypereutrophic subtropical lake located in central Florida. 

Ammonium (NH4

+

) N and soluble reactive P (SRP) flux during sediment resuspension 

were measured under laboratory conditions using intact sediment cores. Ammonium N 

and SRP flux due solely to diffusion were assessed using in situ porewater 

concentrations. Average diffusive flux from sediment to the overlying water was 

estimated to be 25 mg NH4

-

N m-2 d-1 and 1 mg P m-1 d-2. Resuspension fluxes of NH4

+

 and 

SRP were higher than diffusive flux. Soluble reactive P profiles of porewater showed 

distinct profile differentiation, with the surface 0 to 8 cm sediment depth acting as a Pdepletion zone, and the underlying sediment displaying steep gradients in porewater 

SRP. These results suggest that dissolved NH4

+

 and SRP transport from the surface 8 cm 

of sediment was due to sediment resuspension, while below this depth, upward 

mobility of NH4

+

 and SRP was regulated by diffusion. Although dissolved N and P flux 

is upwards (from sediment to water column), during extended periods (annual cycle) 

the lake is functioning as a net sink for N and P by transforming inorganic pools of 

nutrients into organic forms and depositing them on the sediment surface. 

Reddy, K.R., and D.A. Graetz. 1991. Internal nutrient budget for Lake Apopka. Special 

Publication SJ91-SP6. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

EXECUTIVE SUMMARY

Lake Apopka, with a surface area of 12,500 ha (31,000 acres), is located in Central 

Florida, approximately 25 km (15 miles) northwest of Orlando. The average depth of the 

lake is about 2 m. Currently, it is highly eutrophic with high concentrations of algal 
Appendix H 

St. Johns River Water Management District

469 

biomass (chlorophyll a concentrations often exceed 100 mg m-3). Water quality in the 

lake is impacted by both external and internal sources. Historical and current external 

sources of pollution include discharge of excess drainage water from adjacent vegetable 

farms, surface and subsurface runoff from adjacent citrus groves, sewage effluent 

discharge from Winter Garden (this discharge has been stopped for some time), and 

biological nitrogen and carbon fixation. 

The water quality in Lake Apopka can have a significant impact on downstream lakes 

in the Oklawaha River Basin, since lake water eventually flows into some of these lakes. 

In recognition of the problems and potential values of Lake Apopka, the Florida 

Legislature, in 1985, approved funds to study feasible means of restoring the lake. Part 

of this approval was to design a study for better understanding of the external and 

internal nutrient inputs to the lake, which would result in the development of a nutrient 

budget for the lake. 

The bottom sediments in Lake Apopka are highly organic and rich in nutrients. Because 

of shallow water depth and the flocculent nature of these sediments, resuspension of 

the sediment occurs during periods of heavy winds. The release of nutrients from these 

sediments can cause nutrient concentrations in the water column to remain high despite 

reduction of external nutrient loading. The nutrients can be readily utilized by algae 

and other aquatic biota, thus maintaining hypereutrophic conditions in the lake. 

For Lake Apopka, the pollutants of most immediate concern are phosphorus (P), 

nitrogen (N), and carbon (C). Phosphorus and N are essential nutrients which often 

limit the rate of algal primary production, the source of flocculent lake sediments. 

Although C, which is continually supplied through photosynthesis and removed 

through microbial respiration, is a major component of the flocculent organic sediment, 

it is not as important in eutrophication as N and P. Nevertheless, the rate of 

accumulation of flocculent sediments is determined by the balance between C fixation 

via algal photosynthesis and C mineralization through microbial respiration. 

Information on the C budget, then, could indicate the level of reduction of algal 

productivity required to cause the lake to become a net exporter of C. Quantification of 

these internal sources and sinks is essential for accurate prediction of the response of 

Lake Apopka to pollution abatement and for informed appraisal of restoration 

alternatives. 

In recent years, it has become clear that nutrient processing by the aquatic biota and 

sediments of lakes can be a major factor in the determination of trophic status of the 

lake. To evaluate the role of C, N, and P transformations in the sediment-water column 

and its impact on water quality, it is critical to develop a basic understanding of these 

processes. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

470 

The major objectives of the research presented in this report were to: 

• Characterize Lake Apopka sediments for labile and non-labile forms of nutrients 

• Determine the flux of dissolved C, N, and P between sediments and the overlying 

water column 

• Establish the relative importance of biogeochemical transformations of sedimentary 

forms of C, N, and P 

• Determine C and N fixation in the water column 

• Determine the effects of sediment mixing and resuspension on C, N, and P release into 

the water column 

The first objective of this study was to characterize labile and non-labile forms of 

nutrients in Lake Apopka sediments. 

The sediment profile is characterized by five different layers, based on their physical 

consistency. These are unconsolidated floc (UCF), consolidated floc (CF), peat (P), sand (S), 

clay (c), and marl (M). The UCF layer is the surface layer, with an underlying CF layer. 

About 95% of the sediment surface is covered with a UCF layer. During the past 20 years, 

the thickness of this layer has increased at a rate of 1.15 cm yr-1

. 

Labile (dissolved) forms of nutrients in the sediment porewater account for 0.7% of C, 

3.9% of N, and 6.9% of P in the sediments. Historical sedimentation rates based on 210Pbdating techniques were estimated to be 0.03 g cm-2

 yr-1. This yields accumulation rates for 

C, N, and P of 91, 7.1, and 2.9 g m-2

 yr-1, respectively. These values are on the same order of 

magnitude as those estimated by increases in the thickness of surface sediments over the 

past 20 years. 

The second objective of this study was to determine the flux of dissolved C, N, and P 

between sediments and the overlying water column. 

Nitrogen flux from the sediment to the overlying water column was in the range 28–40 mg 

N m-2 d-1. Phosphorus flux was in the range 1.7–2.7 mg P m-2 d-1. Concentration profiles of 

ammonium N and soluble P varied spatially, but not temporally, suggesting that the lake 

is at steady state. Flux of C, N, and P is governed in the UCF sediments by resuspension 

and in the CF sediments by diffusion and mass flow. 

The third objective of this study was to establish the relative importance of 

biogeochemical transformations of sedimentary forms of C, N, and P. 
Appendix H 

St. Johns River Water Management District

471 

One of the transformations of C is decomposition of organic matter. Organic matter 

decomposition was rapid in sediments exposed to oxygen, with about 25% of the initial C 

lost in one year. Under anaerobic conditions, about 6% of the initial C was lost from UCF 

sediments; less than 1% was lost from CF and peat sediments. The decomposition in CF 

and peat sediments was inhibited by an inadequate supply of electron acceptors. 

A second transformation of C is adsorption and diffusion of organic acids. Soluble organic 

C concentrations in the water column and in the sediment porewater were approximately 

the same. Therefore, there is no net transport of C from the sediment to the water. The 

diffusion coefficients for acetic and butyric acids, intermediate products of anaerobic 

decomposition, were 0.46 and 0.71 cm-2 d-1. Acetic acid is more strongly adsorbed in 

sediment than is butyric acid. 

One of the transformations of N is mineralization of organic N to ammonium. Organic N 

mineralization in sediments exposed to oxygen was rapid (0.6 mg N L-1 d-1). Under 

anaerobic conditions, N mineralization rates were in the range 0.26–0.37 mg N L-1 d-1

. 

A second transformation of N is adsorption and diffusion of ammonium N. Ammonium 

adsorption on sediment was stronger under aerobic conditions than anaerobic conditions. 

Ammonium adsorption capacity was higher in the surface sediments and decreased with 

depth. The diffusion coefficients for ammonium moving in the sediment profile were in 

the range 0.6–1.47 cm-2 d-1. 

A third transformation of N is nitrification (oxidation of ammonium N to nitrate N) in 

sediment resuspended into the oxygenated water column. Soluble ammonium in 

anaerobic sediments exposed to oxygen was rapidly nitrified at a rate of 1.95 mg N L-1 d-1

. 

A fourth transformation of N is nitrate reduction. This process can be either assimilatory 

producing biomass, or dissimilatory with NH4

 or N2 being formed. Nitrate reduction rates 

were rapid, with denitrification (nitrate reduction to nitrous oxide and N gas) as the 

dominant process. Denitrification rates were in the range 1.2–2.6 mg N L-1 d-1

. 

The combined processes of nitrification and denitrification in the sediment-water column 

are very important in this system. Nitrification-denitrification processes were rapid in the 

sediment-water column, with removal rates measured up to 50 mg N m-2 d-1. 

One of the transformations of P is adsorption/desorption of phosphate and diffusion of P 

in sediments. Soluble P decreased when anaerobic sediments were exposed to oxygen but 

remained constant when sediments were kept under anaerobic conditions. High 

equilibrium P concentrations in the sediment porewater suggest that P transport is from 

the sediment to the water column. In the short term, P retention in the sediment is due to 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

472 

adsorption, while over the long term, precipitation of calcium phosphates from the water 

column controls the porewater concentration of P. 

The fourth objective of this study was to determine C and N fixation in the water 

column. 

Carbon and N fixation in the water column is a function of light penetration and is 

independent of N and P concentrations in the water. This implies that N and P are not 

limiting the productivity of Lake Apopka. The C fixation rate was 1.9 mg C L-1 d-1

assuming a 12-h photoperiod. On an areal basis, the C fixation rate is 1,400 g C m-2 yr-1. The 

N fixation rate was 0.16 g m-2

 yr-1, suggesting that biological N fixation may not be a 

significant contributor to the total N budget for Lake Apopka. 

The fifth objective of this study was to determine the effects of sediment mixing and 

resuspension on C, N, and P release into the water column. 

Ammonium N release during simulated sediment resuspension of the surface 10 cm was 

in the range 0.4–0.5 mg cm-2 h-1. No significant release in P occurred during this sediment 

resuspension. Profiles of soluble P concentration in sediments suggest that sediment 

resuspension involves the surface 8 cm. 

The results in this report provide information on the relative rates of several 

biogeochemical processes related to C, N, and P cycling in Lake Apopka. It is apparent 

from these results that Lake Apopka is very productive and dynamic in cycling 

nutrients. The nutrient enrichment in the water column is enhanced by sediments 

functioning as a steady source of soluble ammonium and P. The sediments are 

functioning as sinks for nitrate N and for the particulate matter deposited on the 

sediment surface. To quantitatively evaluate the role of sediments in the overall internal 

nutrient budget of the lake, it is critical that two physical processes, i.e. sediment 

resuspension during hydrodynamic events, and steady diffusive flux, be further 

evaluated. 

It should be noted that the rate coefficients reported for various processes were 

measured under laboratory conditions. The relative rates may be different under field 

conditions where several environmental factors influence these processes. Future 

research should be focused on the biogeochemical processes functioning (1) at the 

sediment-water interface, especially on a micro-scale level in the surface 10 cm depth, 

and (2) in the water column during sedimentation of particulate dead algal cells. Since 

the processes functioning are dynamic in nature, they should be evaluated in situ on 

short-term intervals. The information provided in this report should be used in context 
Appendix H 

St. Johns River Water Management District

473 

with the external nutrient inputs when developing management strategies to restore 

Lake Apopka. 

Reddy, K.R., O.G. Olila, E.M. D’Angelo, D.L. Stites, and M. Coveney. 1996. Nutrient 

storage and movement in the Lake Apopka Marsh, Phase III. Contract 94B271:1996. 

Final report submitted to St. Johns River Water Management District, Palatka, Fla. 

IFAS, University of Florida, Gainesville. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

EXECUTIVE SUMMARY

The environmental quality of the Oklawaha Chain of Lakes has been a subject of 

concern for various state agencies, local agencies, and private citizens for more than 

twenty years. Progressive eutrophication has greatly reduced or eliminated many of the 

recreational and water quality values of the lakes. Lake Apopka, the first and largest of 

the chain of lakes, is also the most severely degraded. 

Lake Apopka, with a surface area of 12,500 ha (31,000 acres), is located in central 

Florida, approximately 25 km (15 miles) northwest of Orlando. The average depth of the 

lake is about 2 m. Currently, it is highly eutrophic with high concentrations of algal 

biomass (chlorophyll a concentrations often exceeds 100 μg/L). Water quality in the 

lake is impacted by both external and internal nutrient sources. Historical and current 

external sources of pollution include: discharge of excess drainage water from adjacent 

vegetable farms, surface and subsurface runoff from adjacent citrus groves, sewage 

effluent discharge from Winter Garden (this discharge has been stopped for some time), 

and biological nitrogen and carbon fixation. In addition, nutrient release from bottom 

sediments due to wind-induced resuspension and diffusion is considered an important 

source to the water column. 

In recognition of the problems and potential values of Lake Apopka, the Florida 

Legislature in 1985 passed Chapter 85-148, Laws of Florida, which funded studies 

aimed at determining feasible means for restoring the lake. The effort was furthered by 

the Surface Water Improvement and Management Act of 1987 (Chapter 87-97, Laws of 

Florida), which identified Lake Apopka as a priority water body in need of restoration 

studies. Since enactment of that legislation, diagnostic and feasibility studies have 

resulted in the development of the Lake Apopka Marsh Flow-Way, a project designed 

to restore Lake Apopka by marsh filtration of nutrient-laden lake water. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

474 

The purpose of the Marsh Flow-way Demonstration Project is to acquire the knowledge 

and experience necessary to effectively design and manage the projected full-scale 

marsh flow-way for lake restoration. In order to optimize marsh management for costeffective nutrient removal, it is necessary to understand the fate of nutrients that enter 

the marsh. The Nutrient Storage and Movement Project was designed to measure the 

major nutrient components in the marsh soil and vegetation, determine the rate of 

transformation of nutrients to and from the soil, water column and vegetation, and 

estimate the nutrient retention capacity of the system. 

The objectives of the Phase III research presented in this report were to 

• Determine different P forms and their distribution as affected by drawdown, drying 

and re-flooding 

• Evaluate the changes in organic and inorganic forms of P in the newly accreted 

sediments 

• Develop a baseline on selected soil characteristics (C, N, and P) and compare the 

changes in those characteristics before and after re-flooding 

• Changes in distribution of dissolved nutrients in the soil-water column following these 

management strategies in the constructed marsh 

• Nutrient exchange rates (NER) in the soil-water column under in situ conditions 

The first objective was to evaluate the forms and distribution of soil phosphorus as 

influenced by marsh drawdown, drying and reflooding. 

Drawdown of the marsh increased the bulk density of surface sediments. Compacted 

sediments generally were higher in total P concentration than the pre-drawdown 

sediments. The newly accreted sediments had higher total P concentration than the native 

soil. 

Drawdown caused a shift in sediment P distribution from less soluble to a more soluble 

form, as indicated by the large increase in loosely bound P (1 M KCl-extractable) 

concentration in the newly accreted sediments. 

Drawdown also increased the reactive Fe/Al-P concentrations at the expense of labile 

organic P (NaOH/OP) probably due to P mineralization following exposure and drying. 

The temporal shift in soil P from less soluble to a more soluble form due to drawdown 

may result in an initial flushing of P upon re-flooding. 

The second objective was to evaluate the nutrient exchange rates between soil and 

water column, as influenced by marsh drawdown, drying, and reflooding. 
Appendix H 

St. Johns River Water Management District

475 

Marsh water level and burning wetland vegetation has resulted in increased upward 

diffusive flux of soluble N and P from 10 and 1.3 mg/m2

·day in December 1992 before 

marsh management. 

Drawdown of water level in the South Marsh in June 1994 resulted in partial consolidation 

of floc sediment depth, that may extend the lifetime of the marsh for nutrient removal by 

this process. 

The third objective of the study was to determine the changes in bioavailable P and 

nutrient exchange as a result of water-level drawdown and reflooding. 

Measurements of floodwater dissolved reactive P (DRP) indicated that draining and soil 

exposure could result in large P flux to the overlying water column. 

Phosphorus flux in soils drained for 6 weeks was tenfold higher (334 mg P m-2 day-1) than 

P flux in sols drained for 3 weeks (3 mg P m-2 day-1). 

Soil exposure also resulted in an increase in bioavailable inorganic P (estimated by KCl 

extraction) at the expense of labile organic P pool. The KCl-P pool, initially 0.2% (control), 

increased to 3% and 13% of TP after 3 and 6 weeks’ draining, respectively. 

Results suggest that various fractions of soil P, particularly those in newly accreted 

materials, were highly unstable and could be released in a more available form when 

newly accreted soils experience stress such as exposure and drying. 

Additional research is needed to develop tools which can be used to identify 

management strategies to improve the efficiency of marsh. 

Field application of chemical amendments to reduce P release from native agricultural 

soils should be evaluated prior to flooding. 

Nutrient storage in the belowground portion should be quantified to establish the role of 

vegetation. 

Stability of stored nutrients in soil and floc sediment needs to be established, especially 

with respect to P. 

Simple models should be developed as a tool to evaluate management options to improve 

nutrient removal efficiency of marsh. 
SWIM Plan for Lake Apopka 

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476 

Consideration should be given to include sedimentation ponds to reduce suspended solid 

loads to the marsh. 

Rice, K.G., and H.F. Percival, eds. 1996. Effects of environmental contaminants on the 

demographics and reproduction of Lake Apopka’s alligators and other taxa. Technical 

report 53. Fla. Coop. Fish and Wildlife Res. Unit, University of Florida, Gainesville. 

PROJECT: Fisheries (LA-4-107-D) 

ABSTRACT

Due to high nutrient and pesticide levels, Lake Apopka is considered one of the state’s 

most polluted lakes. Lake water is frequently pumped into and from agricultural areas. 

Also, for years the lake was largely encircled by extensive citrus groves. In addition to 

agricultural chemicals, Lake Apopka receives tertiary treated sewage effluents from the 

municipality of Winter Garden. In 1980, a spill from the Tower Chemical Company 

contaminated the drainage into Gourdneck, the southwest portion of the lake. 

Beginning in 1981, a major decline was observed in juvenile alligators on Lake Apopka. 

Meanwhile, other lakes studied in the St. Johns River drainage showed numerically 

stable or increasing alligator populations. Since 1984, controlled incubation of alligator 

eggs has demonstrated that Lake Apopka has the lowest clutch viability rates 

(proportion that hatch out of total eggs deposited) of any Florida alligator population 

examined. An analysis of alligator eggs collected in 1985 from three Florida lakes 

showed that eggs from Lake Apopka had significantly elevated levels of DDD, DDT, 

and DDE. DDT, DDE, and many other pesticides can act as hormones (chemical signals) 

or as inhibitors to natural hormones in the developing embryo. 

In this study, we found that the total population (≥30 cm) of alligators on Lake Apopka 

decreased approximately 25% from 1980 to 1989 then increased approximately 20% 

through 1995 (P<0.01, ∼R2

adj = 0.80). Juveniles (30–121 cm) decreased by almost 60% 

through 1989 then increased by 50% over the next 6 years (P<0.05, ∼R2

adj = 0.80). We 

could detect a decrease in clutch viability of approximately 41% from 1983 to 1988 and 

then an increase of over 200% through 1995 (P<0.05, ∼R2

adj = 0.82). However, clutch 

viability was higher on Lake Woodruff, our control area, than Lake Apopka (P<0.001, df 

= 103). Viability did not differ between the two lakes for animals of similar size. We 

estimated size distributions of adult nesting females for both areas. Lake Apopka’s 

distribution consisted of larger animals than Lake Woodruff’s. We note that clutch 

viability was higher for the medium-sized animals than for the very large. 
Appendix H 

St. Johns River Water Management District

477 

Plasma sex steroid concentrations did not differ between adult females on lakes Apopka 

and Woodruff. Initial contaminant analyses indicated no correlation between 

concentrations of contaminants found in adult female abdominal fat and egg yolk. 

Clutch viability did not correlate to egg yolk contaminant concentrations. However, 

contaminant levels in maternal abdominal fat had a negative correlation (adj R2

–0.778, P 

= 0.0001) to clutch viability. 

Juvenile alligator females exhibited similar plasma estrogen (E) concentrations among 

all lakes whereas we noted that plasma testosterone (T) concentrations were 

significantly increased on Apopka in comparison to the other lakes. Male bass on 

Apopka had depressed concentrations of 11-keto-testosterone. Initial results indicate 

significantly higher parasite loads for bass from Lake Apopka than from the other lakes 

and ponds. Additionally, white blood cell counts were increased and spleen weight 

decreased for bass from Lake Apopka. 

We noted that neonates from eggs treated with higher doses of DDE (100, 1000 mg/egg) 

and all doses of edstradiol exhibited elevated plasma E concentrations, but significantly 

reduced plasma concentrations. Thus, DDE and E treatments cause abnormal plasma 

hormone profiles, which result in demasculinized males. These results mimic our 

observations in untreated eggs collected from Lake Apopka. 

Male and female juvenile alligators from Lake Griffin and Lake Jesup exhibited 

significantly elevated estrogen/androgen (E/A) ratios as do male alligators from Lake 

Apopka (F = 7.76; d.f. = 6, 467, P < 0.0001). Only males from Lake Apopka showed little 

relationship between body size and phallus morphometrics. Males from Lake Apopka 

had penis tip lengths smaller than males from any other lake, after adjustment for snout 

vent length. 

We provide general discussion and recommendations for future research direction on 

Lake Apopka. Finally, we provide point-by-point conclusions at the end of this 

manuscript. 

CONCLUSIONS

We detected an increasing trend in the juvenile population and in clutch viability on Lake 

Apopka since 1989. Clutch viability is lower on Lake Apopka than on the control area, 

Lake Woodruff. Clutch size was greater on Lake Apopka than Woodruff. However, 

individual egg weight was less. Clutch viability was less among the larger females. 

Similar-sized nesting females produced similar clutch viability rates on lakes Apopka and 

Woodruff. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

478 

We found a difference in the shape and the mean of estimated nesting female size 

distributions on lakes Apopka and Woodruff. Lake Apopka’s nesting females were larger 

on average than Lake Woodruff alligators in 1994 and 1995. 

Sex steroid concentrations did not differ in adult nesting females between lakes Apopka 

and Woodruff, but were significantly different for juvenile animals. Similarly, juvenile 

alligators and adult bass on Lake Apopka had hormone concentrations significantly 

different from other areas. 

There was little correlation between phallus size and body size in male juvenile alligators 

from Lake Apopka, whereas males from six other lakes showed a clear positive 

correlation between body size and phallus size. Circulating sex hormones (estradiol and 

testosterone) were different in these Apopka animals with small phalli (as well as in 

alligators from Lakes Jesup and Griffin), with no correlation existing between circulating T 

and phallus size in the Apopka animals. 

Juvenile alligators captured on Lake Apopka and Lake Woodruff displayed comparable 

responses to acute capture stress. 

We observed no correlation between environmental contaminants found in the female and 

those found in the egg. Contaminants in the adult female were negatively correlated with 

clutch viability rate. 

Laboratory dosing studies of environmental contaminants, for both alligator and turtle 

eggs, produced animals with altered hormonal concentrations. Eggs dosed with DDE 

produced animals with hormone levels that corresponded to levels observed on wild 

animals in lakes Apopka and Woodruff. 

Our data suggest two very different potential fates for alligators (and other vertebrate 

populations) on Lake Apopka. We could be viewing the recovery of a system and only 

the remnants of damage inflicted in the past by environmental contamination or other 

causes. On the other hand, this seeming recovery phase may end, and juvenile animals 

present today might not reproduce or survive. Only through continued monitoring and 

further experimentation can we hope to unravel this mystery. 

Robinson, H. 1999. Bird report, Zellwood Drainage and Water Control District Unit 1, 

Unit 2, and the Zellwin Sand Farm property at Zellwood, Florida. August 15, 1998–
Appendix H 

St. Johns River Water Management District

479 

August 14, 1999. Prepared for St. Johns River Water Management District, Palatka, 

Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 

INTRODUCTION

This is a report on the birds that visited the Zellwood Drainage District Units 1 and 2 

together with the flooded portion of the Zellwin Sand Farm property, all located in 

Zellwood, Florida (Figure 1). This detailed summary covers the period August 15 1998 

to August 14 1999. The survey is ongoing. Table G gives details of the days visited and 

the number of species/individuals seen. This survey involved over 1,000 hours of 

fieldwork. 

An informal discussion was held at Zellwood on August 15, 1998, between birders and 

staff of the St. Johns River Water Management District. One outcome was the urgent 

need by all parties for detailed information on the birds using the farms. Hence the 

survey. 

Initially, the survey concentrated on the flooded fields, but when an unexpected influx 

of sparrows took place the survey then included the tall herbaceous vegetated fields. In 

February 1999 the fields were drained and the farms closed so I didn’t visit the area for 

nearly three weeks. I then started to explore the peripheral areas and found that there 

were interesting and bird-rich woodland areas that unfortunately were not covered 

previously in the fall. Access to the fields was granted again on April 20, 1999. The 

survey now included the herbaceous vegetated fields, the flooded areas on the Sand 

Farm, and the wooded borders. 

The aim of this report is to record what I saw during the year. It is unfortunate that 

apart from the fall, I have been unable to get my most unusual sightings confirmed by 

others. I often wish that there was a designated individual who could come in to 

confirm some of the rather startling finds. The aim is also to identify, as far as possible, 

the habitat used by other species. I hope it indicates the species and numbers that might 

use the area, if it was either deep or shallow flooded. It also shows what may occur if 

the fields remain covered in herbaceous vegetation. 

In addition, I conducted a breeding bird survey during the summer of 1999, and the 

results are included in Appendix A. I have also tried to identify all mammal, butterflies, 

dragonflies, damselflies, reptiles, and amphibians that I came across. Details of these are 

included in Appendices C–F. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

480 

Finally I have taken a brief look at some events that happened during the year and the 

effect that they had on the birds. 

Robinson, H. 2002. Bird usage of Lake Apopka’s North Shore Restoration Area. 

Zellwood Drainage and Water Control District Unit 1, Unit 2, and the Zellwin Sand 

Farm property at Zellwood, Florida. August 15, 1999–August 14, 2000. Prepared for 

St. Johns River Water Management District, Palatka, Fla. 

PROJECT: North Shore Restoration (LA-3-303-M) 

INTRODUCTION

This is the second report on the birds that visited the Zellwood Drainage District Units 

1 and 2 together with the eastern end of the Zellwin Sand Farm Property, all located in 

Zellwood, Florida (Figure 1). This detailed summary covers the period from August 15, 

1999, to August 14, 2000. This survey is ongoing. Table D gives details of the days site 

visited, the hours spent surveying and the number of species/individuals seen. This 

survey involved 1,207 hours of fieldwork. 

The survey started in August 1998, as there was an urgent need for detailed information 

on the birds that visited the flooded fields. After the fields were drained in February 

1999, the fields continued to be a major draw for birds. In all seasons, this area 

continues to surprise with many species setting new records for the State of Florida. 

During this year the only water has been at the Sand Farm. At times there have been 

areas of mud, and at other times it has been full to the banks. The area underwater is 

decreasing, perhaps 250 acres now against the original 300 acres. The rest of the area 

has been undisturbed. It has not been static as the vegetation has continued to evolve. 

Much of the northern and eastern areas are now clothed in some very tall, dense plant 

growth. There has been no significant change to the border habitats. 

The actual area surveyed has varied according to season, weather conditions and from 

time to time, because of the work of the road system. More time has been spent in Unit 

1 and the Sand Farm than in Unit 2. The extreme southern end of the area, i.e., the area 

south of Hooper Farms Road, received the least attention due to time constraints. I have 

however tried to keep to the same route seasonally in order to make the counts 

comparable. 

The aim of this report is to record what I saw during the 12 months. I have also, where 

relevant, included early fall records from the first year in order that there is a full 
Appendix H 

St. Johns River Water Management District

481 

picture of the fall migration in 2000. I have tried to identify, as far as possible, the 

habitat used by each species. This habitat usage is detailed in Table B. In case the reader 

has not seen the first report, I am including a summary of the wetland habitat usage 

together with my estimates of the species/numbers that would visit the flooded fields if 

they were either deep or shallow flooded. 

In addition, I conducted a breeding bird survey during the summer of 2000. The results 

of this and last year’s survey are included in Appendix A. I have also tried to identify 

all mammals, butterflies, dragonflies, damselflies, reptiles, and amphibians that I came 

across. Details of these, for the two years, are included in Appendices C–F. 

I have provided a systematic list of the bird species seen over the two years August 15 

1998–August 14, 2000. With this I have detailed the highest recorded count for each 

species. This is all in Table E. 

Finally, I have taken a look at how the changing vegetation has effected the bird 

population. 

Schelske, C.L. 1994. Assessing nutrient limitation in a hypereutrophic lake. Lake Reserv. 

Manage. 9(2):112. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

ABSTRACT

Nutrient limitation in Lake Apopka, a hypereutrophic lake in north central Florida, was 

assessed with nutrient enrichment bioassays, dilution bioassays, and chemical 

measurements in an 18-month study. Results of nutrient enrichment bioassays with 

natural phytoplankton assemblages showed that phytoplankton were nitrogen limited 

in 18 of 19 monthly assays. Phosphorus was the limiting nutrient in one experiment. 

These results are consistent with chemical measurements. Phosphorus limitation was 

not expected because average total phosphorus is approximately 200 μg P/L. In 

addition, phytoplankton store excess phosphorus as polyphosphate. Nitrogen was 

limiting because combined inorganic nitrogen is low (<50 μg/L) compared to 

chlorophyll a that ranged from 50 to 200 μg/L. Because algal biomass was high, dilution 

experiments were conducted to determine the effect of nutrient reduction on 

phytoplankton growth. A dilution series of lake water and simulated lake water 

containing no nitrogen and phosphorus was used to test the effects of nutrient 

reduction in 2 x 2 factorial experiments with nitrogen and phosphorus. In these 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

482 

experiments, the importance of nitrogen limitation decreased with increasing dilution 

of simulated lake water. Algal growth was nitrogen limited in undiluted lake water, but 

at high dilution, algal growth was colimited by nitrogen and phosphorus. These 

dilution experiments provide guidelines on the amount of phosphorus removal needed 

to achieve specific reductions in algal biomass. 

Schelske, C.L. 1997. Sediment and phosphorus deposition in Lake Apopka. Special Publication 

SJ97-SP21. Palatka, Fla.: St. Johns River Water Management District. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

EXECUTIVE SUMMARY

Sediment studies in Lake Apopka were undertaken with two major objectives. The first 

was characterization and determination of the origins of the flocculent and consolidated 

sediment layers. This objective is important because the origin of sediments is 

presumed to have changed abruptly in 1947 when the lake primary producer 

community shifted from macrophyte dominance to phytoplankton dominance. Several 

independent approaches were employed to characterize sediments and determine their 

origin. The second major objective was to estimate lake-basin sedimentation of mass, 

organic matter, total phosphorus (TP), and non-apatite inorganic phosphorus (NAIP) 

after 1947 and also for shorter periods after 1947 when phytoplankton became the 

dominant primary producer. To meet these objectives, a high quality data set for 46 

survey and 8 historic cores was collected (see Appendices B and C). Historic cores were 

210Pb dated to provide a chronology of historic changes in sediment and nutrient 

deposition. Stratigraphic feature in historic and survey cores were correlated as a means 

of obtaining time-dependent markers in the undated survey cores. Data from the survey 

cores arranged on an equal area grid were equally weighted in developing basinwide 

estimates. 

Highly organic, flocculent sediments produced during the phytoplankton phase were 

hypothesized to be lower in dry weight fraction and with a lower total carbon/total 

nitrogen (TC/TN) ratio than sediments produced during the macrophyte phase. This 

difference was expected because macrophytes require structural organic carbon to grow 

upright. This structural carbon is degraded slowly compared to more labile forms in 

phytoplankton; thus a higher TC/TN ratio is found in sediments produced during the 

macrophyte phase. A stratigraphic marker of this type was used to determine the 

thickness of flocculent sediments at historic and survey stations. 
Appendix H 

St. Johns River Water Management District

483 

Several stratigraphic markers were used to infer the change from macrophyte to 

phytoplankton dominance in the lake. The ratio of TC/TN, fraction dry weight, and TP 

concentration provided stratigraphic evidence that flocculent sediments were produced 

as by-products of autotrophic metabolism during the recent, 50-year period of 

phytoplankton dominance. These variables, which were analyzed in all cores, were 

used to establish the thickness of flocculent sediments. That flocculent sediments were 

produced during the planktonic phase was verified with additional analyses, including 

the chemical measurement of diatom silica and analysis of diatom microfossils. 

Highly organic sediments such as those found in Lake Apopka are not common in some 

geographic areas, but are characteristic of many Florida lakes (Brenner and Binford 

1988). Lake Apopka forms the headwaters of the Ocklawaha River and receives 

relatively small inputs of allochthonous organic matter from its small drainage area, 

headwater spring and rainfall. Lake Apopka, therefore, may differ from many Florida 

lakes in that a high proportion of its sedimentary organic matter has been formed 

historically from organic matter produced photosynthetically in the lake, either from 

the macrophyte community during the macrophyte phase or from phytoplankton 

community during the phytoplankton phase. Results presented here provide many 

lines of evidence for the two different sources of sedimentary organic carbon in Lake 

Apopka. 

Data on diatom microfossils provide additional support for criteria used in stratigraphic 

zonation. Three distinct assemblages were present in the diatoms identified from LA9-

95, a historic core collected in 1995. These included (1) a diverse assemblage dominated 

by benthic taxa (Amphora ovalis, Cyclotella stelligera, Cymbella sp., Pinnularia sp., and 

Nitzschia sp.) that was found below the zone of flocculent sediments, (2) an assemblage 

dominated by Aulacoseira italica, Pseudostaurosira brevistriata, Staurosirella pinnata, and 

Staurosira construens found at the bottom of the zone of flocculent sediments, and (3) an 

assemblage comprised of 75–80% A. italica in the uppermost zone of flocculent 

sediments. The diverse benthic assemblage also differed in that its absolute abundance 

was approximately an order of magnitude less than the overlying assemblage. 

Data on microfossil diatoms provide evidence that water transparency changed 

markedly in a few decades. Water transparency inferred from the diatom assemblage 

present during the macrophyte phase indicates high water transparency such that 

benthic algae grew on the lake bottom. By contrast, the meroplanktonic diatom, A. 

italica now is the dominant diatom in the lake because it can survive in the aphotic 

environment on the lake bottom. Decreased transparency is attributed to increases in 

phytoplankton standing crop and other factors. Increased standing crop of 

phytoplankton is one of the consequences of nutrient enrichment. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

484 

The ratio of planktonic to benthic (P/B) diatoms also provides evidence that the 

primary producer community shifted from macrophytes to phytoplankton at the time 

when flocculent sediments were first deposited. A. italica is the major phytoplankton 

species in the lake presently; therefore, the P/B ratio is highest in the upper 15 cm 

where this species is dominant (75–80% of the assemblage). The P/B ratio increases 

upcore as does the concentration of TP. True benthic species will be replaced by other 

forms if water transparency decreases as the result of increased standing crops of 

phytoplankton or other factors. These data indicate that the changes in the lake’s 

primary producer community since the 1940s and earlier were driven by increased 

nutrient loading. 

Establishing the thickness of flocculent sediments at survey stations allowed the 

calculation of inventories (storage) of mass, organic matter, TP, and NAIP at each 

station. The thickness of flocculent sediments varied greatly among the 46 survey cores 

and ranged from 1 to 136 cm. Flocculent sediments were highly organic averaging 63% 

of sediment mass. Storage of sediment mass and TP also varied among stations. This 

variability can be illustrated by noting the <5% of the total storage of TP was found at 

the 10 stations with the lowest storage and that 63% of the TP storage was found at the 

15 stations with the highest storage. This variability does not affect estimates of 

basinwide storage which are based on equal areal weighting for each station. 

Variability in sediment deposition over the lake basin is attributed to the dynamics of 

sedimentation that focus sediments at high sedimentation sites. Sediments that are 

focused at high deposition sites have in part been transported from other areas of the 

lake that are subject to sediment resuspension. Stations with high sedimentation rates 

are characterized as depositional sites. These sites preserve the paleolimnological record 

and must be identified to infer historical conditions in the lake. Stations with low 

sedimentation, transitional, or no-depositional sites were in the central part of the lake 

where the effects of wind action on sediment resuspension would be greatest. 

Resuspension of sediments was evaluated as a potential source of phosphorus to the 

water column. An amount equivalent to approximately 400 μg TP/L in the water mass 

is present in the upper 5 cm of sediment and an amount equivalent to 1200 μg TP/L is 

present in the upper 10 cm. Concentrations as large as 400 μg TP/L are found very 

rarely during monitoring of the lake. These calculated amounts, therefore, are 

undoubtedly overestimates of the amount that might be resuspended at any one time, 

particularly because sediments are not likely to be resuspended over the entire lake 

bottom during most storm events and because some areas in the center of the lake 

which are subjected to the greatest effects of wave action have thin layers of flocculent 

sediments. 
Appendix H 

St. Johns River Water Management District

485 

Conventional models of dating sediments with 210Pb could not be used in Lake Apopka 

because the construction of dikes in the 1940s reduced the area of the lake basin. This 

reduction in surface area of the lake invalidates the assumption in models that 210Pb flux 

to the sediments is constant over time. A hybrid model which adjusted ages so that the 

zone of flocculent sediments was 50 yr old was used to date flocculent sediments. 

During this time period, the flux of 210Pb can be assumed to be constant. Ages and 

sedimentation rates calculated from the hybrid model indicated that sedimentation rate 

increased at least 2.1-fold and total phosphorus accumulation rate (TPAR) increased 

from 3.3-fold in the last 50 years. These results were then used to estimate the change in 

TP sedimentation over time. 

Flocculent sediments were highly organic, averaging 63% organic matter measured as 

loss on ignition (LOI); therefore, sedimentation accumulation and mass sedimentation 

rate (MSR) are determined largely by organic matter. This characteristic is important in 

evaluating the 210Pb chronology. A mean 2.1-fold increase in MSR in 50 yr was found 

using the hybrid model. This 2.1-fold increase can be attributed to an increase in organic 

matter production by phytoplankton in 50 years because sediments are highly organic. 

Increased production and sedimentation of organic matter over time can then be used 

to partly explain the relatively flat excess 210Ph profiles. An increase in phytoplankton 

production is one of the expected consequences of increased phosphorus loading to the 

system that is inferred from historic increases in TP storage in the sediments. 

Several lines of evidence, including TPAR obtained from 210Pb dating, indicate that 

whole-basin rates of TP storage increased during the planktonic phase, approximately 

the last 50 yr. Average rates of TP storage for the period of phytoplankton dominance 

were estimated to be 45,000 kg yr-1. This is slightly smaller than 49,100 kg yr-1

, an 

estimate by Brezonik et al. (1978) for net TP deposition (storage) in 1977. Average rates 

of deposition were 61.6% larger in the last 10 years and about 50% smaller during the 

first 10 years of phytoplankton dominance if the rate of TP accumulation increased 4-

fold at a logarithmic rate during the 50-yr period of phytoplankton dominance. 

The high abundance of meroplanktonic algae in near-surface sediments and storage of 

phosphorus by this algal community may be one of the factors contributing to 

artificially high MSR and TPAR at the tops of sediment cores. Data from LA9-95 show 

that A. italica has the greatest relative abundance in the upper 15 cm. The uptake and 

storage of phosphorus by meroplankton is a biogeochemical process that may account 

for the relatively large storage of phosphorus in recent sediments. Polyphosphate stored 

in these cells may be a significant phosphorus sink. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

486 

Estimated whole-basin inventories (storage) of organic matter in the last 50 yr are 

reasonable compared to estimated organic matter production by phytoplankton. Data 

on annual phytoplankton production in the lake are limited; however, organic matter 

sedimented in the past 50 yr is on the order of 10% of estimated phytoplankton 

production. This comparison indicates that calculated storage of organic matter closely 

approximates storage evaluated independently. This comparison and comparable 

estimates of TP sedimentation by Brezonik et al. (1978) and the present investigation 

validate data obtained in the present investigation. The whole-basin inventory of TP in 

flocculent sediments was 2.25 x 106 kg (2,250 metric tons). This inventory which 

accumulated in 50 yr is 54 times larger than the present inventory of TP in the water 

column. These data indicate that residence time of phosphorus in the water column is 

short, on the order of one year. This calculation undoubtedly underestimates recent 

rates of TP sedimentation in the lake which have increased historically. These data 

show that the sediments are a significant sink for phosphorus. 

The present investigation provides data to quantify phosphorus storage in sediments 

and to demonstrate that phosphorus loading and sedimentation have increased since 

1947 during the planktonic phase of the lake. Data from the investigation are used to 

show that phosphorus storage has increased at least 3-fold in the last 50 yr based on 

decadal comparisons and as much as 4-fold if annual rates are compared. Changes in 

the assemblage composition of diatom microfossils in flocculent sediments also provide 

additional evidence that phosphorus loading has increased markedly in the past 50 yr. 

Schelske, C.L., F.J. Aldridge, and H.J. Carrick. 1992. Phytoplankton-nutrient interactions in 

Lake Apopka. Special Publication SJ92-SP9. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

EXECUTIVE SUMMARY

Phytoplankton-nutrient interactions in Lake Apopka were studied under an agreement 

between the St. Johns River Water Management District and the University of Florida. 

The study was instituted because Lake Apopka contains high concentrations of total 

phosphorus, and excessive algal (phytoplankton) growth has been identified as the 

prime symptom of eutrophication in this lake. High standing crops of phytoplankton 

are the result of excessive phosphorus loading and contribute to low light penetration in 

the water column. Studies on this shallow, hypereutrophic lake were conducted from 

December 1989 to November 1991. Results are presented in five chapters. 
Appendix H 

St. Johns River Water Management District

487 

INTRODUCTION (CHAPTER 1) 

Chapter 1 presents the purpose and scope of the report including a literature review on 

previous environmental conditions and management activities. The literature review 

includes discussion of the dramatic environmental changes that occurred in 1947 when 

the lake changed from a clear-water, macrophyte-dominated system to a turbid, 

phytoplankton-dominated system. 

PHYTOPLANKTON PRODUCTION AND AMBIENT LAKE CONDITIONS (CHAPTER 2) 

Results of a sampling program conducted from February 1990 to July 1991 are 

presented. Data collected twice-monthly include photosynthetically active radiation 

(PAR), water column light extinction, Secchi disc transparency, water temperature, 

dissolved oxygen, and chlorophyll a. This chapter also includes monthly measurements 

of phytoplankton productivity. 

Except for water temperature and lake level, no distinct seasonal patterns were found in 

the parameters measured during the study. Seasonal patterns, if present, are obscured 

by large between-sampling differences in data collected twice-monthly. We obtained 

evidence that phytoplankton dynamics in this shallow lake are controlled by short-term 

dynamics in environmental processes. Algae and other materials that have settled to the 

bottom may be resuspended by wind-generated turbulence and periodically comprise a 

large fraction of measured phytoplankton and total suspended solids. 

The high standing crops of phytoplankton are a major factor causing high turbidity in 

the lake. Measurements of Secchi disc transparency showed that the limit of visibility in 

the water ranged from 6–14 inches. Large ranges in other variables were found 

including Kt

 or light extinction (3.1–12.8 m-1), water temperature (17.0–32.5oC), 

chlorophyll (44–217 mg m-3), maximum gross primary productivity (133–1149 mg C m-3

h-1), and areal gross primary production (116–568 mg C m-2 h-1). 

Although twice-monthly sampling is not adequate to characterize the short-term 

variation in phytoplankton dynamics in Lake Apopka, our results are valid to describe 

average conditions in the lake. These results provide an important database on which 

management decisions can be based and from which the results of management 

decisions can be assessed. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

488 

NUTRIENT ENRICHMENT BIOASSAYS (CHAPTER 3) 

Results of monthly bioassays for nitrogen (N) and phosphorus (P) nutrient limitation 

are presented. The experimental approach was based on measuring responses of the 

algal community to nutrient enrichments of N, P, or N+P compared to non-enriched 

controls. Experiments were run in the laboratory under controlled light and 

temperature conditions using the natural phytoplankton assemblages present in the 

lake at the time water was collected. Comparison of experiments conducted in Lake 

Apopka with those conducted in the laboratory showed no statistically significant 

difference in response. 

We conducted 20 experiments at approximately monthly intervals from December 1989 

to July 1991 to determine if N or P was the primary limiting nutrient or a secondary 

limiting nutrient. Results from these experiments indicated that N was the primary 

limiting nutrient in 19 of the 20 experiments and that P was the primary limiting 

nutrient only once. Secondary P limitation was found in only 5 of the 19 experiments in 

which responses to N+P were statistically greater than the response to N alone. 

We conclude that N is the primary limiting nutrient because the water of Lake Apopka 

generally contains large supplies of phosphorus that can be utilized for phytoplankton 

growth when the water is enriched with N. We also conclude that N limitation in Lake 

Apopka is the result of excessive P loading to the lake and that P supplies must be 

reduced to reduce standing crops of algae. 

NUTRIENT-DILUTION BIOASSAYS (CHAPTER 4) 

Chapter 4 presents results of bioassays for nitrogen (N) and phosphorus (P) nutrient 

limitation that were combined with dilution experiments. These studies are called 

nutrient-dilution bioassays because the experiments utilized nutrient enrichment with 

N, P, and N+P in combination with dilution of lake water to determine the effect of 

reduced nutrient supplies on phytoplankton growth and production. Lake water was 

diluted from 5% to 95% in these experiments. Effects of nutrient reduction must be 

known to predict or assess the impact of reduced nutrient loading on phytoplankton 

production and other ecosystem processes. 

Although complex interactions characterized these experiments, results provide insight 

on the relative roles of N and P in establishing and maintaining the present 

hypereutrophic conditions in Lake Apopka. Most of the phosphorus occurs in 

phytoplankton, and a large portion is stored in phytoplankton as polyphosphates. This 

finding is important because the stored polyphosphate in phytoplankton can be used 

for growth in the absence of phosphorus in the water. Phytoplankton in the lake, 
Appendix H 

St. Johns River Water Management District

489 

therefore, are generally N-limited because of phosphorus storage in phytoplankton 

cells. 

Clear evidence for reduction of biomass with dilution was obtained only in N 

treatments because N enrichment allowed the utilization of stored phosphorus for 

phytoplankton growth and eventually caused phytoplankton to be P-limited. 

In general for treatments other than N enrichment, the biomass yield increased with 

dilution. This effect was most dramatic with the combined treatment of N+P, but was 

also evident in the control and P treatments. The unexpected increase in phytoplankton 

growth with dilution possibly can be attributed to one or more of the following factors: 

dilution increases the supply of nutrients for the diluted phytoplankton, zooplankton 

grazing on phytoplankton is relieved with dilution, artificial diluents like MIS may 

contain substances that enhance growth either directly or indirectly, allelopathic 

substances (growth-inhibiting compounds) may have been diluted, and light 

attenuation was reduced by dilution. 

The cellular content of stored phosphorus in algae increased with dilution more than 

3-fold. In the present marsh restoration project, increased P-storage capacity with 

dilution may aid in the removal of P from Lake Apopka by (1) removing available P 

more swiftly in waters that have been diluted with effluent from the marsh and (2) 

decreasing the internal P load by producing more P-rich particles to be deposited in the 

wetland. The relative effectiveness of this internal “P-pump,” in concert with P removal 

by the wetland, requires additional experimentation in order to assess its role in the net 

export of P from Lake Apopka. 

INDICATORS OF NUTRIENT STATUS (CHAPTER 5) 

Nutrient enrichment bioassays (NEB) appear to be the most reliable indicator of 

nutrient limitation to phytoplankton in Lake Apopka. In addition to NEB, physiological 

indicators of N and P limitation can be used to provide an independent validation. For 

indices to be used as predictive tools of phytoplankton nutrient status, they need to be 

calibrated in parallel with NEB for phytoplankton assemblages of varying nutrient 

deficiency. The most appropriate methods for this are HEP (hot-water extractable 

phosphorus) storage or P-uptake for evaluation of P-limitation and N-uptake to 

corroborate N-limitation. All three of these assays are non-hazardous (avoid the use of 

harsh chemicals), simple to conduct (experimentation duration <24 h), and do not 

require any specialized equipment (e.g., radioisotopes) other than that used to measure 

basic water chemistry. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

490 

Routine chemical measurement of dissolved inorganic nitrogen in the water can be used 

to determine if phytoplankton are N-limited. The nutrient status of phytoplankton 

relative to N is not complicated by N storage in phytoplankton cells. 

Schelske, C.L., M.F. Coveney, F.J. Aldridge, W.F. Kenney, and J.E. Cable. 1999. Wind or 

nutrients: Historic development of hypereutrophy in Lake Apopka, Florida. T. 

Berman, ed. In Proceedings from the Kinneret Symposium on Limnology and Lake 

Management 2000+, September 6–11, 1999, Tiberias, Israel. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

ABSTRACT

Lake Apopka is a large (125 km2), shallow (mean depth = 1.63 m), polymictic, 

hypereutrophic lake located 25 km north of Orlando, Florida. Before 1947, the 

macrophyte-dominated lake was characterized by clear water and a highly prized 

sports fishery. A switch in the primary producer community from macrophyte 

dominance to phytoplankton dominance has been attributed to a hurricane in 1947 that 

uprooted the submersed macrophytes. Paleolimnological data, however, show that 

phosphorus (P) loading increased before the switch. We propose shading by increased 

growth of phytoplankton stimulated by P enrichment as an alternative mechanism for 

the switch. Other workers have used records of storm tracks over Florida to rule out 

wind effects from the 1947 hurricane as the primary cause for the switch. Principal 

sources of P loading before the 1940s were from sewage discharge and citrus farming 

and processing. In the 1940s, P loading increased after 80 km2 of adjacent sawgrass 

(Cladium jamaicense) wetlands were diked and drained so fertile histosols (muck soils) 

could be used for high-intensity agriculture. Eventually muck farm agriculture 

provided 85% of the areal total phosphorus (TP) loading, approximately 400 mg m-2

 yr-1. 

Inferences from the paleolimnological record show that phytoplankton production and 

sedimentation of organic compounds derived largely from phytoplankton increased 

several fold during the phytoplankton phase in response to accelerated P loading. 

Phytoplankton and meroplankton that are resuspended during wind events and their 

by-products are presently the major components of light attenuation. Resuspension of 

meroplankton that assimilate nutrients in an aphotic benthic environment is an 

important factor in phytoplankton dynamics. Interactions of wind, nutrients, and light 

are important in maintaining the present hypereutrophic condition and its associated 

aphotic benthic environment. Management programs are underway to reduce P loading 

and increase water clarity and restore submersed macrophytes. Our paleolimnological 

results show that TP sedimentation is at least 360 mg m-2

 yr-1. TP residence time in the 
Appendix H 

St. Johns River Water Management District

491 

water based on this TP sedimentation rate is 0.93 yr, which indicates sediments are an 

important P sink. Decreases in nutrient loading and the role of biological sinks that may 

affect or accelerate the response to reduced TP loading are discussed in an evaluation of 

current restoration strategies. 

Schelske, C.L., and W.F. Kenney. 2001. Model erroneously predicts failure for 

restoration of Lake Apopka, a hypereutrophic, subtropical lake. Hydrobiologia

448:1–5. 

PROJECT: Restoration Monitoring (LA-6-803-S) 

ABSTRACT

A recent paper (Bachmann et al. 1999) based on analysis of literature data predicts 

failure for restoration plans implemented by the St. Johns River Water Management 

District (SJRWMD) for Lake Apopka, a large (125 km2), shallow (mean depth = 1.63 m), 

polymictic lake in central Florida. A marsh flow-way designed to remove particulates 

from inflowing water from Lake Apopka as a means to improve downstream and lakewater quality is part of the restoration plan. According to Bachmann et al. (1999) 

restoration “will be ineffective in removing particles from the lake” and fail because 

estimated time for removal of 2.21 million tons of historic sediments in a constructed 

marsh flow-way is 329 yr. This inadvertently proposed mining hypothesis given as a 

condition for successful restoration is based on questionable assumptions, i.e., removing 

all the historic sediments deposited over a 50-yr period with the flow-way and 

exporting concurrent sedimentation while historic sediments are being removed. These 

questionable assumptions are used in an erroneous, discontinuous model of sediment 

dynamics that does not justify the alternate approach for restoration of Lake Apopka 

suggested in their paper. 

Schiffer, D.M. 1994. Quality of water and bottom sediments, and nutrient and dissolved-solids 

loads in the Apopka-Beauclair Canal, Lake County, Florida 1986–90. Water-Resources 

Investigations Report 93-4103. Tallahassee, Fla.: U.S. Geological Survey. 

PROJECT: External Nutrient Budget (LA-1-101-D) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

492 

ABSTRACT

The water entering Lake Beauclair, in the Ocklawaha River chain of lakes in central 

Florida, has high concentrations of the nutrients nitrogen and phosphorus. Major 

sources of the nutrients entering Lake Beauclair are Lake Apopka outflow and drainage 

from farming operations adjacent to the Apopka-Beauclair Canal. The U.S. Geological 

Survey began a study in 1986 to determine the relative contribution of nutrient loads 

from these two sources. 

Two flow and water quality monitoring sites were established to obtain data needed to 

calculate loads leaving Lake Apopka and at a control structure (the Apopka-Beauclair 

Canal lock and dam) between the two lakes. Water samples were collected at those sites 

biweekly for analysis of major ions during 4 years of the study. The study, which was 

originally scheduled to end in 1989, was extended to 1991 to provide an additional 2 

years of data collection at a constriction built at the lake-outflow gaging site. Prior to 

1988, discharge could not be gaged at the site because of low velocities. The constriction 

increased velocities in the canal and made it possible to gage discharge at the site. 

Regression analysis of discharge data collected at the gaged sites indicated that 64% of 

the variation in discharge at the lake-outflow site is explained by discharge at the lock 

and dam, and other hydrologic variables (rainfall, water-surface slope) explained 8% of 

the variation. 

The quality of water in the Apopka-Beauclair Canal is relatively uniform during periods 

between storms. Analysis of water samples collected 1 to 2 days after storms, however, 

indicated that water quality is much more variable during these periods because of the 

effects of farm inflow (to the canal) at both the lake outflow and lock-and-dam sites. 

Sand, silt, and clay account for most of the native materials in the bed sediments of the 

canal, but muck (the highly organic fraction of the bottom sediments characterized by a 

high water content) and organic material are deposited downstream from Lake Apopka 

to a distance of about 0.5 mile (the location of the lake-outflow site). Higher median 

concentrations of carbon, and nitrogen and phosphorus species (except ammonia 

nitrogen) were measured in bottom sediments at the lake-outflow site than at the lockand-dam site, an indication that much of the nutrient load leaving the lake is not being 

transported downstream to Lake Beauclair. 

Nutrient and dissolved-solids loads were computed for the two monitoring sites based 

on daily mean discharge and water-quality data linearly interpolated between samples. 

Loads at the lock and dam were fairly constant (a reflection of the controlled discharge 

at the site) except during periods of increased discharge (when gates were opened). 

Loads at the lake-outflow site were much more variable (a reflection of the more 

variable discharge at that site). 
Appendix H 

St. Johns River Water Management District

493 

An alternative approach for determining the relative nutrient-load concentration was 

derived using water-quality data for both locations and discharge data for the lock and 

dam. This approach involved the computation of a “canal-effective load,” which is a 

measure of the effect on the total load measured at the lock and dam from farm 

activities along the canal and physical and chemical processes occurring in the canal 

between the two monitored sites. The canal-effective load represents the net increase (or 

decrease) in load at the lock and dam, above (or below) the load that would have been 

received from Lake Apopka if there were no farm discharge to the canal. 

The maximum monthly nitrate-plus-nitrite nitrogen load at the lock and dam during 

the study was 41 tons in April 1987, and the maximum monthly canal-effective nitrateplus-nitrite nitrogen load was 6.44 tons in September 1988. The canal-effective total 

nitrogen load generally was less than 10% of the total nitrogen load at the lock and dam. 

The annual phosphorus load ranged from 33 tons in the 1987 water year to 9.1 tons in 

the 1990 water year; canal-effective phosphorus load accounted for 11.4% of the annual 

phosphorus load in 1987 and 33% in 1990. 

Much of the constituent load transported through the lock and dam on the ApopkaBeauclair Canal was transported during periods of high discharge. In April 1987, when 

discharges were as high as 589 cubic feet per second, loads transported through the lock 

and dam accounted for 59% of the ammonia-plus-organic nitrogen load, 61% of the total 

nitrogen load, 59% of the phosphorus load, 51% of the total organic carbon load, and 

47% of the dissolved-solids load transported during the 1987 water year. 

The canal-effective nitrogen load accounted for less than 10% of the total nitrogen load 

at the lock and dam, but most of the total phosphorus load was attributable to the canaleffective load. In December 1987 and January 1990, 69 and 73% of the total phosphorus 

load, respectively, was due to the canal-effective load. During the summer months of 

1989, both load calculation methods indicated large inflows to the canal. In June and 

July 1989, 50% and 60%, respectively, of the total phosphorus load was attributable to 

the canal-effective load. 

Load computations using the canal-effective load approach indicated that, with the 

exception of phosphorus, nutrient and dissolved-solids loads due to farm activity along 

the canal account for 10% or less of the total load at the Apopka-Beauclair Canal lock 

and dam. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

494 

Schramm, H.L., Jr., and L.L. Pugh. 1996. Gizzard shad stock estimate for Lake Apopka, 

Florida. Contract 95W121. Miss. Coop. Fish and Wildlife Res. Unit. Submitted to St. 

Johns River Water Management District, Palatka, Fla. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

Gizzard shad (Dorosoma cepedianum) have achieved a large biomass in Lake Apopka, 

Florida. Removal of a large portion of this biomass will remove significant amounts of 

phosphorus in this highly eutrophic lake and help create conditions more conducive for 

establishing desirable sportfish populations. Under the direction of the St. Johns River 

Water Management District, 281, 198 kg of gizzard shad were commercially removed 

from Lake Apopka in 1995 by gill nets. Evaluation of this restoration method requires 

determining the proportion of the total gizzard shad population harvested. This report 

provides population estimates of gizzard shad prior to harvest and evaluates methods 

used to produce the population estimates. 

Population estimates were calculated by change-in-composition, depletion (Leslie 

estimate), and Baranov’s catch equation methods. Input data for these calculations 

included harvest and fishing effort for the duration of the commercial fishery (16 

January 5–April 1995); age, length, weight, and gender of fish in experimental gill net 

(6.4–12.7 cm square mesh) samples collected before and after the commercial fishery 

and monthly during the commercial fishery; and length data from commercial gill net 

catches during August–November 1995. Age was determined by analysis of sagittal 

otoliths obtained from the sampled fish. Validation of otoliths for aging gizzard shad 

was constrained by lack of otoliths collected throughout the year; however, marginal 

increment analysis of otoliths collected during January–June suggested otoliths 

provided accurate ages of gizzard shad in Lake Apopka. We assumed the ages of 

gizzard shad assigned by otolith analysis were accurate and used these ages in 

population estimation calculations. 

The changes-in-composition method estimated the population of Lake Apopka gizzard 

shad was 1,618,354 fish (95% confidence limits [CL] = 1,441,597 and 1,795,111 fish) 

weighing 657,537 kg (95% CL = 585,721 and 729,354 kg). This estimate excludes the 

segment of the population too small to be effectively sampled by the experimental gill 

nets (<280 mm). 

The depletion method estimated the population was 1,505,811 fish (95% CL = 2,925,094 

and 4,969,049 fish) weighing 2, 195,874 kg (95% CL = 1,656,481 and 2,813,972 kg). This 

estimate is for fish longer than 280 mm and age 1 or older. Expanding the estimate to 
Appendix H 

St. Johns River Water Management District

495 

the entire population resulted in an estimated 12,041,034 fish weighing 2,911,809 kg. 

This estimate equate to a standing crop of 233 kg/hectare, which is lower than expected 

for hypertrophic Lake Apopka. 

Population estimates from the change-in-composition method and the catch equation 

method both provided estimates with reasonable and relatively narrow confidence 

limits. Although the catch equation method resulted in a population estimate more than 

twice the estimate obtained by the change-in-composition method, both estimates must 

be considered equally reliable based on similarly narrow confidence limits. Both 

methods are subject to errors in measurement of input parameters obtained at the 

beginning and end of the harvest period. 

A total of 281, 198 kg and an estimated 402,493 gizzard shad were harvested from Lake 

Apopka during January–April 1995. This harvest was 25% and 9% of the number of 

harvestable fish estimated by the change-in-composition and catch equation methods, 

respectively; and 43% and 11% of the weight of harvestable fish estimated by the 

change-in-composition and catch equation methods, respectively. 

Future estimation of Lake Apopka gizzard shad should use the change-in-composition 

and catch equation methods. Both methods are subject to errors in measurement of 

input parameters obtained at the beginning and end of the harvest period. The 

reliability of future population estimates can be increased by greater harvest; complete 

subsampling of landings to measure length, weight, gender, and age of at least 300 fish 

during each month of the commercial fishery; and measuring length, weight, gender, 

and age of at least 300 fish from experimental gill net samples collected immediately 

before and after the commercial harvest program. Future interpretation of population 

estimates by these two methods should consider trends in population estimates and 

sensitivity analyses for variation in input parameters should be performed. 

Schramm, H.L., Jr., and L.L. Pugh. 1997. Gizzard shad stock estimate for Lake Apopka, 

Florida 1995. Special Publication SJ97-SP10. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

Gizzard shad (Dorosoma cepedianum) have achieved a large biomass in Lake Apopka, 

Florida. Removal of a large portion of this biomass will remove significant amounts of 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

496 

phosphorus in this highly eutrophic lake and help create conditions more conducive for 

establishing desirable sportfish populations. Under the direction of the St. Johns River 

Water Management District, 281, 198 kg of gizzard shad were commercially removed 

from Lake Apopka in 1995 by gill nets. Evaluation of this restoration method requires 

determining the proportion of the total gizzard shad population harvested. This report 

provides population estimates of gizzard shad prior to harvest and evaluates methods 

used to produce the population estimates. 

Population estimates were calculated by change-in-composition, depletion (Leslie 

estimate), and Baranov’s catch equation methods. Input data for these calculations 

included harvest and fishing effort for the duration of the commercial fishery (16 

January – 5 April 1995); age, length, weight, and gender of fish in experimental gill net 

(6.4–12.7 cm square mesh) samples collected before and after the commercial fishery 

and monthly during the commercial fishery; and fish length and weight data from 

commercial gill net catches during August–November 1995. Age was determined by 

analysis of sagittal otoliths obtained from the sampled fish. Validation of otoliths for 

aging gizzard shad was constrained by lack of otoliths collected throughout the year; 

however, marginal increment analysis of otoliths collected during January–June 

suggested otoliths provided accurate ages of gizzard shad in Lake Apopka. We 

assumed the ages of gizzard shad assigned by otolith analysis were accurate and used 

these ages in population estimation calculations. 

The change-in-composition method estimated the population of Lake Apopka gizzard 

shad was 1,618,354 fish (955 confidence limits [CL] = 1,441,597 and 1,795,111 fish 

weighing 657,537 kg (95% CL = 585,721 and 729,354 kg). This estimate excludes the 

segment of the population too small to be effectively sampled by the experimental gill 

nets (,280 mm). 

The depletion method estimated the population was 1,505,811 fish (95% CL = 903,490 

and 18,390,461 fish) weighing 928,634 kg (95% CL = 557,182 and 11,341,397 kg). This 

estimate is for gizzard shad longer than 300 mm. Although similar to the change-incomposition estimate, the precision of the estimate was low. The variation in catch rates 

and relatively low harvest reduced the reliability of this estimate. 

The catch equation method estimated the population was 3,877,582 fish (95% CL = 

2,925,094 and 4,969,049 fish) weighing 2, 195,874 kg (95% CL = 1,656,481 and 2,813,972 

kg). This estimate is for fish longer than 280 mm and age 1 or older. Expanding the 

estimate to the entire population resulted in an estimated 12,041,034 fish weighing 

2,911,809 kg. This estimate equates to a standing crop of 233 kg/hectare, which is lower 

than expected for hypereutrophic Lake Apopka. 
Appendix H 

St. Johns River Water Management District

497 

Population estimates from the change-in-composition method and the catch equation 

method both provided estimates with reasonable and relatively narrow confidence 

limits. Although the catch equation method resulted in a population estimate more than 

twice the estimate obtained by the change-in-composition method, both estimates must 

be considered equally reliable based on similarly narrow confidence limits. Both 

methods are subject to errors in measurement of input parameters obtained at the 

beginning and end of the harvest period. 

A total of 281, 198 kg and an estimated 402,493 gizzard shad were harvested from Lake 

Apopka during January–April 1995. This harvest was 25% and 9% of the number of 

harvestable fish estimated by the change-in-composition and catch equation methods, 

respectively; and 43% and 11% of the weight of harvestable fish estimated by the 

change-in-composition and catch equation methods, respectively. 

Future estimation of Lake Apopka gizzard shad should use the change-in-composition 

and catch equation methods. Both methods are subject to errors in measurement of 

input parameters obtained at the beginning and end of the harvest period. The 

reliability of future population estimates can be increased by greater harvest; complete 

subsampling of landings to measure length, weight, gender, and age of at least 300 fish 

during each month of the commercial fishery; and measuring length, weight, gender, 

and age of at least 300 fish from experimental gill net samples collected immediately 

before and after the commercial harvest program. Future interpretation of population 

estimates by these two methods should consider trends in population estimates and 

sensitivity analyses for variation in input parameters should be performed. 

Schramm, H.L., Jr., and L.L. Pugh. 1997. Gizzard shad stock estimate for Lake Apopka, 

Florida 1996. Special Publication SJ97-SP11. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT: Rough Fish Harvesting (LA-3-302-M) 

EXECUTIVE SUMMARY

Gizzard shad (Dorosoma cepedianum) have achieved a large biomass in Lake Apopka, 

Florida. Removal of a large portion of this biomass will remove significant amounts of 

phosphorus in this highly eutrophic lake and help create conditions more conducive for 

establishing desirable sportfish populations. Under the direction of the St. Johns River 

Water Management District, 249,748 kg of gizzard shad were commercially removed 

from Lake Apopka in during March–May 1996. Evaluation of this restoration method 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

498 

requires determining the proportion of the total gizzard shad population harvested. 

This report provides population estimates of gizzard shad prior to harvest and 

evaluates methods used to produce the population estimates. 

Population estimates were calculated by change-in-composition, depletion (Leslie 

estimate), and Baranov’s catch equation methods. Input data for these calculations 

included harvest and fishing effort for the duration of the commercial fishery (7 March–

23 May 1996); age, length, weight, and gender of fish in experimental gill net (6.4–12.7 

cm square mesh) samples collected before and after the commercial fishery and 

monthly during the commercial fishery; and fish length and weight data from 

commercial gill net catches during January–May 1996. Age was determined by analysis 

of sagittal otoliths obtained from the sampled fish. Validation of otoliths for aging 

gizzard shad was constrained by lack of otoliths collected throughout the year; 

however, marginal increment analysis of otoliths collected during January–June 

suggested otoliths provided accurate ages of gizzard shad in Lake Apopka. We 

assumed the ages of gizzard shad assigned by otolith analysis were accurate and used 

these ages in population estimation calculations. 

The change-in-composition method estimated the population of Lake Apopka gizzard 

shad age-1 and older in February 1996 was 726,228 fish (95% confidence limits [CL] = 

718,706 and 733,750 fish) weighing 245,683 kg (95% CL = 243,138 and 248,228 kg). The 

estimate for the total population (all ages) was 2,0 19,268 fish weighing 458,129 kg. 

The depletion method estimated the population of age-1 gizzard shad in February 1996 

was 899,681 fish (95% CL = 732,753 and 1,288,907 fish) weighing 375,527 kg (95% CL = 

305,851 and 537,990 kg). The depletion method estimated the total population was 

2,200, 192 weighing 589,201 kg. 

The catch equation method estimated the population of age-1 gizzard shad in January 

1995 was 2,073,744 fish (95% CL = 1,947,327 and 2,204,113 fish) weighing 1,174,361 kg 

(95% CL = 1,102,771 and 1,248,189 kg). Expanding the estimate to the entire population 

resulted in an estimated 6,455,109 fish weighing 1,917,002 kg. 

We consider all three methods appropriate for the population estimated and the data 

available. Therefore, the best estimate of the total gizzard shad population is 2,0 19,268–

6,455,109 fish weighing 458,129–1,917,002 kg. This estimate equates to a density of 162–

518 fish/hectare and a biomass of 37–154 kg/hectare which is lower than expected for 

hypertrophic Lake Apopka. 

In January–April 1995, the subsidized commercial fishery harvested 281, 198 kg of 

gizzard shad; estimated exploitation rates, based on three population estimates for 
Appendix H 

St. Johns River Water Management District

499 

January 1995 were 24–43%. During March–May 1996, the subsidized commercial fishery 

harvested 249,748 kg of gizzard shad; this harvest amount was 67–102% of the 

estimated harvestable population weight in February 1996. 

While the comparison with other biomass estimates and high exploitation rates suggest 

the population estimates are low, several population variables support high 

exploitation rate and, hence, relatively small population size. First, gizzard shad in Lake 

Apopka had rapid growth rate and recruited to the commercial fishery at age-1; new 

recruits are a large portion of the commercial landings. Second, high exploitation rates 

are expected to result in overfishing. The lower estimated population in 1996 than in 

1995 (Schramm and Pugh 1996), and the decline in mean weight of fish in each age class 

from February 1996 to May 1996 indicate overfishing occurred. 

We conclude that the population estimates provided in this report are reasonable. Based 

on these estimates, the harvest of gizzard shad during 1995 and 1996 substantially 

reduced the Lake Apopka gizzard shad population. 

Segal, D.S., and C.D. Pollman. 1991. Assessment of potential sediment contamination for the 

restoration of Lake Apopka. Special Publication SJ91-SP8. Palatka, Fla.: St. Johns River 

Water Management District. 

PROJECT: Internal Nutrient Budget (LA-1-102-D) 

EXECUTIVE SUMMARY

Lake Apopka forms the headwaters of the Oklawaha chain of lakes, eutrophic to 

hypereutrophic water bodies located in central Florida approximately 25 km northwest 

of Orlando. Once a popular resort area noted for its game fishing, Lake Apopka is now 

ranked as the seventeenth-most eutrophic lake in Florida. This condition results largely 

from direct backpumping of nutrient-enriched irrigation water from muck farms on the 

northern shores of the lake into Lake Apopka and from past sewage treatment practices 

by the City of Winter Garden. The St. Johns River Water Management District 

(SJRWMD) has been charged by the Florida state legislature to assess the feasibility of 

restoring Lake Apopka to Class III water quality standards (Chapter 17-3, F.A.C.). 

Priority issues in the restoration program outlined by the SJRWMD in the Lake Apopka 

Surface Water Improvement and Management (SWIM) Plan include poor water quality 

and excessive accumulation of flocculent organic sediments. 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

500 

Dredging nutrient-rich sediments from Lake Apopka and reuse of the dried muck has 

been suggested as a restoration technique. The newly initiated marsh flow-way project 

uses a restored 950-acre wetland to filter water from the lake, which will result in 

substantial deposition of lake sediments in the restored wetland. Artificial barriers to 

stabilize the sediment, reduce nutrient release, and improve plant habitat are also being 

considered as possible tools in lake restoration. A survey of levels and potential toxic 

effects of substances in Lake Apopka sediments was necessary to support these and 

other projects. This contamination assessment is especially important if dredged 

sediments are reused, such as for soil amendments, as a cost-recovery method for 

dredging. 

The goals of this project were the following: 

1. To analyze sediment samples from two depths at ten locations in Lake Apopka for the 

152 elements and compounds on the EPA Target Compound List 

2. To tabulate the analytical results 

3. To determine the potential toxic and deleterious effects of those elements or 

compounds on lake biota, fisheries, and other recreational uses of the lake 

An extensive literature search revealed a large number of lake water toxicity studies, 

which focused primarily on chronic and acute effects. In contrast, the availability of 

similar guidelines or criteria for sediment-associated toxicity was much more limited, 

and criteria were available only for the Great Lakes, Canada, and Wisconsin. Because 

these criteria were developed for northern temperate systems, their applicability to 

Lake Apopka is uncertain. Therefore, for this survey, when contaminant concentrations 

exceeded both the north-temperate sediment criteria and the reported EPA threshold 

for toxicity in water, the contaminant was considered potentially toxic to the lake’s 

biota. 

Comparison of contaminant concentrations in bulk sediments with toxicity criteria 

developed for lake water generally provides a very conservative analysis. Sediment 

concentrations reflect not only the dissolved free forms, but also forms that are 

chemically bound to sediment particles, which often renders them less toxic. These 

comparisons should serve to identify potential contamination problems, but may also 

exaggerate actual toxicity risks. 

In Lake Apopka sediments, 13 of the 152 elements and compounds occurred in 

sufficiently high concentrations to warrant detailed examination. Based on these 

comparisons, copper and lead appear to pose the greatest threat of toxicity to Lake 

Apopka. Concentrations of arsenic and selenium exceed both the sediment threshold 

criteria and chronic aquatic threshold criteria but not the acute aquatic threshold 
Appendix H 

St. Johns River Water Management District

501 

criteria, and hence may be toxic to the lake’s biota. Sediment concentrations of barium, 

beryllium, chromium, and zinc suggest potential toxicity as well, although the evidence 

for toxicity is less well established because of the lack of aquatic toxicity studies 

(barium, beryllium) or because levels in the sediments compared across media 

(sediments and water) did not consistently exceed established criteria (zinc and 

chromium). Concentrations of nickel are below established threshold criteria. Toxicity 

threshold data for vanadium, acetone, and benzoic acid were insufficient to determine 

the potential toxicity of these contaminants in Lake Apopka. 

Although elevated levels of some elements and compounds appear to occur in Lake 

Apopka sediments, it is difficult to assess the effects these contaminants will have on 

the lake’s biota because of the complex interactions that occur in biological systems. For 

example, the toxicity of many elements declines in hard water. The relatively high 

water hardness in Lake Apopka sediments should ameliorate potential toxic effects of 

these elements. However, because of the debilitating health effects that some 

contaminants cause, combined with the desire to restore Lake Apopka to a healthy 

sport fishery lake, it is suggested that further consideration be given to those elements 

and compounds that exceeded both sediment and lake water threshold criteria values. 

Sheng, P., X. Meng, and S. Schofield. 1994. Assessment of hydrodynamic conditions in 

Lake Apopka. Vol. I. Analysis of wind data from Lake Apopka and Orlando 

Airport. Final report for St. Johns River Water Management District, Palatka, Fla. 

University of Florida, Gainesville. 

PROJECT: Hydrodynamic Survey (LA-4-109-D) 

INTRODUCTION

Lake Apopka is a large (31,000 acres), shallow (mean depth 5.4 ft) hypereutrophic lake 

located approximately 30 miles northwest of Orlando, Fla. Through the SWIM program, 

the St. Johns River Water Management District (SJRWMD) is creating a 5,000-acre 

marsh flow-way on former agricultural lands on the NW shore of Lake Apopka. The 

flow-way will recirculate Lake Apopka water to remove solids and nutrients by 

filtration. Through 1-2 intakes located on the eastern side of the marsh, lake water is 

drawn into the marsh, while subsequently the marsh water is discharged from the 

northern end near the entrance to the Apopka-Beauclair Canal (ABC). To effectively 

utilize the marsh, it is desirable to minimize hydraulic short-circuiting, a condition 

which occurs when most of the discharge water is quickly drawn into the intakes. To 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

502 

minimize the hydraulic short-circuiting of discharge water, it is essential to quantify the 

flow patterns in Lake Apopka during a variety of meteorological conditions. 

Among the various meteorological conditions, wind forces play the dominant role in 

affecting Lake Apopka’s flow patterns. Thus, in order to be able to quantitatively assess 

the probability of hydraulic short-circuiting, it would be useful to understand the wind 

field patterns at Lake Apopka. 

CONCLUSIONS

1. Lake Apopka is located in the middle of the Florida Peninsula, where the weather 

conditions are influenced by the air flows over the Atlantic Ocean and Gulf of Mexico, 

cold air from the north and warm air from the south. The weather conditions in this area 

are very unstable due to such a complicated air flow environment, and vary from year to 

year. 

2. The wind speed ranges at Orlando Airport are obviously very different from those at 

Lake Apopka. These differences should be mainly resulted from the totally different 

surrounding environments at these two sites, which would also affect the turbulence 

structure of the wind field, and in turn affect the wind forces over the lake. Therefore, it 

would be inappropriate to use the wind data at Orlando Airport as a substitute for the 

wind conditions at Lake Apopka. 

3. Generally, N/NE and S/SW wind prevail over Lake Apopka on yearly and monthly 

bases. 

4. From the wind roses, we can tell that the extent to which N/NE and S/SW prevail is 

quite limited due to (1). To decide the optimal location and to design the intake and 

discharge points for the flow-way to minimize hydraulic short-circuiting, the chance of 

occurrence of wind in each direction should be equally considered. 

Sheng, P., and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake 

Apopka. Vol. II, Bathymetric surveys of the northwest section of Lake Apopka. 

Final report prepared for St. Johns River Water Management District, Palatka, Fla. 

University of Florida, Gainesville. 

PROJECT: Hydrodynamic Survey (LA-4-109-D) 
Appendix H 

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503 

ABSTRACT

The northwest section of Lake Apopka was surveyed during December 1992. A 

bathymetric survey grid was laid out to obtain fine resolution (200 ft) contour spacing 

along the northwest area of the lake, encompassing approximately 10 square miles. The 

survey was conducted using a microwave positioning system for positioning and an 

Innerspace depth sounder. The depths were corrected for a lake level of 66 ft (MSL). 

Results of the 1992 survey are summarized in Part A of this volume. 

Results of the 1992 bathymetric survey were used in the three-dimensional model 

simulation of wind-driven circulation in Lake Apopka (Sheng and Meng 1994, Vol. V of 

the report series). Results of the model simulations suggested that a 50 ft grid resolution 

is needed to more accurately represent the flow and dye dispersion in the northwest 

section of Lake Apopka. Hence, a finer resolution (50 ft) bathymetric survey was 

conducted over a 0.843 square mile area in the northwest section of the lake during 

February 1994. Results of the 1994 survey are presented in Part B of this volume. 

Sheng, P., and S. Schofield. 1994. Assessment of hydrodynamic conditions in Lake 

Apopka. Vol. III, Lake Apopka 1992 field data report. Final report prepared for St. 

Johns River Water Management District, Palatka, Fla. University of Florida, 

Gainesville. 

PROJECT: Hydrodynamic Survey (LA-4-109-D) 

ABSTRACT 

A field study on the hydrodynamics of Lake Apopka was conducted in August and 

September 1992. Various meteorological and hydrodynamic instruments were mounted 

on three instrument towers located in the northwest, central, and southeast sections of 

the lake. Comprehensive data at the Center Tower and Southeast Tower were 

successfully collected over a 14-day period. The Northwest Tower malfunctioned most 

of the time due primarily to the damages incurred by lightning strikes during the first 

week of deployment, except during several 3-day periods. Results of the data analysis 

showed that diurnal wind variation associated with lake breeze generated significant 

seiche oscillation and currents (up to 10 cm/s) in the lake. Diurnal temperature 

fluctuation was found to be significant at all the stations, although vertical temperature 

stratification was not significant. The flow data are used for numerical simulation as 

described in Vol. V of the report. Significant temporal variation in suspended sediment 

concentration (100–400 mg/L) was also found. 
SWIM Plan for Lake Apopka 

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504 

Sheng, P., S. Schofield, X. Meng, and K. Ellins. 1994. Assessment of hydrodynamic 

conditions in Lake Apopka. Vol. IV, Dispersion of discharge water from the 

Apopka-Beauclair Canal into Lake Apopka. Final report prepared for St. Johns 

River Water Management District, Palatka, Fla. University of Florida, Gainesville. 

PROJECT: Hydrodynamic Survey (LA-4-109-D) 

ABSTRACT

As part of the study entitled “Assessment of Hydrodynamic Conditions in Lake 

Apopka” funded by the St. Johns River Water Management District, a tracer study was 

conducted by the Coastal and Oceanographic Engineering Department of the 

University of Florida to track the discharge from the Apopka-Beauclair Canal to Lake 

Apopka. 

On January 27 1993, 25 pounds of Rhodamine-WT dye was injected into the ApopkaBeauclair Canal in the northwest quadrant of Lake Apopka during a weather event 

exhibiting northerly winds. The canal discharge was at approximately 100 cfs, 50% of 

full capacity. The dye was tracked with a fluorometer mounted on a boat from 15:30 

until 17:24. At the same time, aerial photographs were taken from an airplane flying at 

3500 ft altitude between 14:50 and 16:56. In addition to the Rhodamine dye, SF6 was also 

injected into the Apopka-Beauclair Canal and water samples were collected from the 

boat. Results from the fluorometer readings, aerial photographs, and analysis of SF6

samples all revealed consistent dispersion patterns of the discharge water: an initial 

southward movement and a subsequent eastward movement of the discharge plume, 

which contained a large amount of mud. The discharge water did not reach the water 

intake on the west shore during the course of the study period, although there was 

some westward movement of the mud and dye plume. Model simulations suggested 

that finer resolution bathymetry and numerical grid could lead to improved model 

results. A finer (50-ft) resolution bathymetric survey was conducted in February 1994 

and its results were used in the refined model simulation for investigating the potential 

of short circuiting. 
Appendix H 

St. Johns River Water Management District

505 

Sheng, P., S. Schofield, X. Meng, and K. Ellins. 1994. Assessment of hydrodynamic 

conditions in Lake Apopka. Vol. V, A three-dimensional hydrodynamic numerical 

model of wind-driven circulation in Lake Apopka (LAHM3D): Theory, Model 

documentation, user’s manual and model simulation. Final report prepared for St. 

Johns River Water Management District, Palatka, Fla. University of Florida, 

Gainesville. 

PROJECT: Hydrodynamic Survey (LA-4-109-D) 

INTRODUCTION

This report details the development, calibration, and validation of LAHM3D model 

(Lake Apopka Hydrodynamic Model-3D), which is a numerical model for calculating 

three-dimensional unsteady flow in Lake Apopka. Given proper boundary and initial 

conditions, geometry and bathymetry of a water body, the model is able to calculate the 

three-dimensional, time-dependent distributions of flow velocity (u, v, w), temperature 

(T), density (ρ), and dissolved species concentration (c) in Lake Apopka. 

CONCLUSIONS

LAHM3D model has been developed to simulate the wind-driven circulations in Lake 

Apopka. Results of a two-day model calibration and an eight-day model validation are 

quite reasonable, based on comparison between simulated and measured currents. 

Pending further improvement, the model can be used to provide detailed 3-D 

circulation patterns in Lake Apopka over long time periods as well as over transient 

events of short durations. 

The “irregularity” in the measured data at the Southeast Tower suggests the significant 

influence by abrupt bathymetric variation and hence, the need for finer-resolution 

bathymetric data to accurately represent the abrupt depth variation for a successful 

model simulation. Future study should also measure the water level in the lake so that 

model simulation of water level can be validated. Despite our effort, we did not obtain 

good data at the Northwest Tower. Tracer study, as opposed to in-situ mooring, could 

be used to obtain circulation patterns there. 

The LAHM3D model could be further enhanced to include the following: 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

506 

• A moving boundary (flooding-drying) algorithm to simulate the movement of 

shoreline during severe storm conditions 

• A vegetation canopy model to parameterize the effect of vegetation on circulation in 

the marsh area 

• A 3-D sediment transport model to allow the simulation of movement of fine 

sediments in various parts of Lake Apopka 

• A 3-D water quality model to allow estimation of nutrient budget of Lake Apopka for 

better lake management 

Shireman, J.V., and K.K. Opuszynski. 1992. Ichthyofaunal reconstruction for the management 

of phytoplankton. Special Publication SJ92-SP4. Palatka, Fla.: St. Johns River Water 

Management District. 

PROJECT: Ichthyofaunal Reconstruction (LA-4-206-F) 

EXECUTIVE SUMMARY

Experimental ponds were used to test the hypothesis that bighead carp, a filter-feeding 

fish, could improve water quality and reduce the excessive growth of nuisance algae in 

Lake Apopka. Six experimental ponds were built adjacent to the lake and received 

water from Lake Apopka. Four ponds were stocked with bighead carp. Two ponds 

were not stocked and used as control ponds. 

Out of 16 physics-chemical parameters measured, seven were significantly different 

between Lake Apopka and the ponds. Secchi disk visibility was greatest in the ponds, 

along with higher values of specific conductance. Total alkalinity in the fish stocked 

ponds was higher than in the lake, but no difference was found between the control 

ponds and the lake. Total nitrogen, total phosphorus, total chlorophyll a, and filtered 

chlorophyll a were higher in the lake. 

No differences in plankton abundance were found between the lake and the control 

ponds for blue-green algae (Botryococcus braunii), total algae number, rotifers, copepods, 

and total zooplankton number groups. These parameter values, however, were 

significantly lower in the ponds stocked with bighead carp than in the lake. It suggests 

that bighead carp exerted some effect on the pond ecosystem, but this effect was not 

large enough to cause significant differences between the stocked and unstocked ponds. 

The algal community in the ponds and lake was characterized by an extreme 

dominance of blue-green algae, reduced number of total algal species, and a clear 

dominance by several algal species (Spirulina lesissuna, Lyngbya contorta, L. limnetica, L. 
Appendix H 

St. Johns River Water Management District

507 

lagerheinii and Microsystis incerta). A large green algae (Botryococcus Braunii), despite low 

numerical occurrence, constituted an important component of the algal biomass (more 

than 45% at the lake intake site and more than 25% in the ponds, based on chlorophyll a

determination). Bighead carp fed selectively on B. braunii, which comprised 66–70% of 

the volume and 50–60% of the dry weight of the fish food. Bighead carp did not reduce 

algal numbers in the ponds but did decrease the ratio of blue-green/green species in the 

pond algal community. Using the data collected in this study, we calculated that a 

biomass of 750 kg/ha of bighead carp would be needed to cause a significant reduction 

in B. braunii abundance in Lake Apopka within eight days. This biomass was not 

achieved during the study due to the slow growth and high mortality of stocked fish 

and the short experimental time period. The small size of the fish also contributed to 

their inability to reduce the algal biomass. 

Shumate, B.C., C.L. Schelske, T.L. Crisman, and W.F. Kenney. 2002. Response of the 

cladoceran community to trophic state change in Lake Apopka, Florida. Journal of 

Paleolimnology 27:71–77. 

PROJECT: Phytoplankton-Nutrient Interactions (LA-4-104-D) 

ABSTRACT

A paleolimnological evaluation of cladoceran microfossils was initiated to study 

limnological changes in Lake Apopka, a large (125 kg2), shallow (mean depth = 1.6 m), 

warm, polymictic lake in central Florida. The lake switched from macrophytes to algal 

dominance in the late 1940s, creating a Sediment Discontinuity Layer (SDL) that can be 

visually used to separate sediments derived from macrophytes and phytoplankton. 

Cladoceran microfossils were enumerated as a means of corroborating extant 

eutrophication data from the sediment record. Inferences about the timing and 

trajectory of eutrophication were made using the cladoceran-based paleoreconstruction. The cladoceran community of Lake Apopka began to change abruptly in 

both total abundance and relative% abundance just before the lake shifted from 

macrophytes to algal dominance. Alo affinis, a mud-vegetation associated cladoceran, 

disappeared before the SDL was formed. Plankton and benthic species also began to 

increase below the SDL, indicating an increase in production of both planktonic and 

benthic species. Chydorus cf. spaericus, an indicator of nutrient loading, increased relative 

to all other cladocerans beginning in the layer below the SDL and continuing upcore. 

Changes in the transitional sediment layer formed before the lake switched to 

phytoplankton dominance, including an increase in total phosphorus concentration, 

suggest a more gradual eutrophication process than previously reported. Data from this 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

508 

study supported conclusions from other paleolimnological studies that suggested 

anthropogenic phosphorus loading was the key factor in the euthrophication of Lake 

Apopka. 

St. Johns River Water Management District. 1999. Wetland hydraulic investigation 

project, Lake Apopka test channel status report. Technical memorandum 38. 

Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

OBJECTIVE: 

The objective of this study is to investigate the relationship between vegetation 

characteristics and flow resistance in shallow wetlands with emergent vegetation. The 

focal point of the study is the selection of an appropriate methodology, including a set 

of vegetation parameters, enabling the formulation of a relationship between 

vegetation, and flow characteristics in a wetland environment. The vegetation 

characteristics considered include type of vegetation, vegetation density, stem diameter, 

stem height, percent cover, and leaf area. Flow characteristics considered include flow 

depth, flow velocity, and flow resistance as quantified by Manning’s roughness 

coefficient. 

St. Johns River Water Management District. 2000. District water management plan. 

Palatka, Fla. 

PROJECT: District Water Management Plan (LA-6-501-M) 

EXECUTIVE SUMMARY

All five water management districts (WMDs) are required to prepare district water 

management plans (DWMPs) and update them every five years. The first update of the 

St. Johns River Water Management District (SJRWMD) DWMP is summarized in this 

document. 

DWMPs provide long-range guidance for WMD activities and present a compilation of 

water resource information that forms the basis for water management. SJRWMD’s 

DWMP sets direction for the District’s strategic plans, fiscal plans, and other planning 

efforts. 
Appendix H 

St. Johns River Water Management District

509 

The overall goal for the DWMPs and activities of all the WMDs is stated in the Water 

Resources element of the State Comprehensive Plan (Chapter 187, FS) as follows: 

Florida shall assure the availability of an adequate supply of water for all competing 

uses deemed reasonable and beneficial and shall maintain the functions of natural 

systems and the overall present level of surface and groundwater quality. Florida shall 

improve and restore the quality of waters not presently meeting water quality 

standards. 

The format of the DWMPs was developed through the cooperative efforts of the five 

WMDs and the Department of Environmental Protection (DEP). Each plan provides 

goals, issues, objectives, and strategies for each of the four WMD areas of responsibility 

(AORs): 

• Water supply 

• Flood protection and floodplain management 

• Natural systems 

The state’s goal for water resources is realized through the individual district goals for 

each AOR. Issues in the SJRWMD plan were identified in resource assessments and a 

series of workshops held in 14 counties for local government staff, elected officials and 

the public. The issues will be addressed through implementation of DWMP strategies 

over the next five years. Progress will be tracked using measures specific to each 

district’s particular programs in addition to a set of state performance measures 

developed by the WMDs, DEP and the Governor’s Office. 

Maps portraying the results of the resource assessments can be found in the complete 

plan, which also contains general information on the SJRWMD such as its natural 

resources, population and land use and an overview of each of its ten major watersheds. 

This summary document presents the goal, issues, objectives, strategies, and 

performance measures for each AOR and also issues, strategies and performance 

measures specific to each watershed. 

St. Johns River Water Management District. 2001 (draft). Lake Apopka marsh flow-way 

plan for initial operation and pesticide monitoring and exposure management. 

Palatka, Fla. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

510 

SUMMARY

Reduction in P loading is a primary component of the Lake Apopka Restoration 

Program and the restoration efforts for the downstream Ocklawaha Chain of Lakes. 

Ongoing drainage of the MFW site discharges a fraction of labile P to Lake Apopka. The 

labile pool of P in the soils increases while the site is dry, which may result in even 

greater discharges of P when the MFW finally starts operation. The restoration of Lake 

Apopka and downstream lakes in the Ocklawaha Chain of Lakes (e.g., Beauclair, Dora, 

and Eustis) will be delayed by not operating the MFW. 

Not operating the MFW not only slows restoration of Lake Apopka but also does not 

completely remove the risks from soil pesticide residues. While dry, the soils remain 

exposed to terrestrial wildlife. The soil thresholds (Exponent 2000) discussed in this 

plan and in a previous risk analysis by ATRA (1997) suggest that OCPs do not pose an 

acute toxicity threat to wildlife, but may pose a long-term sub-lethal risk. During 

operation, the residual OCP concentration in the soils of the MFW create limited sublethal risk for wildlife; but these risks appear to be low. This is supported by the 

observation that when the MFW Demonstration Project was in operation from 1990 to 

1997, no bird deaths or sick birds were observed at the site. The former fields north of 

Phase I, which are the locations for future MFW phases, have been flooded since 1994 to 

reduce soil oxidation and mineralization. No deaths of birds have been observed in any 

of these areas as well. Moreover, in the MFW, there will be minimal exposure to the 

existing contaminated soils due to the rapid accrual of new sediment, dense vegetation 

within the cells, and the biodegradation of the OCPs under anaerobic conditions. 

Although the chronic risks to wildlife appear low, the District will implement a 

monitoring and management program to track OCP levels in soils and biota to ensure 

that the realized risks are indeed low. District personnel will be at the MFW regularly 

for monitoring and maintenance and will be able to act quickly and effectively if 

problems do arise. If problems develop, the MFW’s pumps and water control structures 

will allow changes in water levels or flows to be rapidly implemented. The information 

gathered as part of the OCP monitoring effort for the MFW will be available to guide 

restoration efforts at the NSRA and other wetlands. 

Restoration of Lake Apopka will yield substantial ecological and economic benefits. 

Initiation of operation of Phase I of the MFW is a critical step towards realizing these 

benefits. Operation of Phase I also provides a means of rapidly reducing the risks to 

wildlife posed by OCPs in the farmed soils. For these reasons, it appears prudent to 

initiate operation of Phase I as described in this document. 
Appendix H 

St. Johns River Water Management District

511 

Stenberg, J.R., D.L. Day, and G.R. Best. 1991. Development of natural vegetation in the Lake 

Apopka Marsh Flow-Way Demonstration Project: Phase I—Baseline conditions, fall 1990. 

Special Publication SJ91-SP11. Palatka, Fla.: St. Johns River Water Management 

District. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

EXECUTIVE SUMMARY

The objective of this paper is to present the results of a study of the baseline vegetation 

conditions in the Apopka Marsh Demonstration Project. Data collected during this 

study will provide a pre-flooding reference point for comparison with future 

evaluations as the marsh develops. 

For the purposes of this report, discussion of the marsh is divided into two sections—

the north and south marshes. This division not only differentiates the two sites by land 

use history, but also separates the marshes into the inflow marsh (south marsh) and 

outflow marsh (north marsh). Historically, the north marsh has been farmed for the 

longest time (1950–1988). The south marsh has been intermittently farmed since about 

1965. 

A sampling grid containing permanent community and temporary biomass sampling 

plots was established in the fall of 1990 along a downstream gradient from the lake 

water inlet to the outflow pumps. Also, a 600 m transect was established from near the 

inlet downstream along the flow direction to provide higher resolution measurements. 

Sampling intensity was 0.014% of the total marsh area. 

Data collected consisted of plant species composition, percentage cover, height, density, 

phenology, and water depth. Aboveground vegetation was clipped at ground level 

from one plot per sampling node. Belowground biomass was sampled at grid points 

near the inlet to determine preliminary estimates of belowground biomass averages and 

variation. Soil cores were collected and placed in a greenhouse under a moist soil 

treatment to determine the composition of the soil seed bank. 

Sixty-four plant species were found. Each plant species was categorized according to its 

wetland affinity. The categories were as follows: 

• Obligate Hydrophyte—found in wetlands >99% of the time 
SWIM Plan for Lake Apopka 

St. Johns River Water Management District

512 

• Facultative-Wetland—usually found in wetlands 67–99% of the time 

• Facultative—found in wetlands 34–66% of the time 

• Facultative-Upland—occasionally found in wetlands 1–33% of the time 

• Upland—seldom found in wetlands <1% of the time 

The proportions of species by wetland affinities were: obligate hydrophyte (51%), 

facultative-wetland (24%), facultative (16%), facultative-upland (8%), and upland (2%). 

The north marsh was dominated by dogfennel (Eupatotiwn capillifolium) stands 

separated by grass and herb fringed canals. The south marsh was a complex aggregate 

of wetland and marginal wetland plants, including, dayflower (Commelina diffusa), 

water primrose (Ludwigia octovalvis), smartweed (Polygonum punctatum), arrowhead 

(Sagittafia lancifolia), and cattail (Typha latifolia). Vegetative co-dominance within both 

the north and south marshes was shared by six species. The occurrence of common 

south marsh plants in the north can be attributed to the exploitation of occasional 

patches and canal edges. Mean aboveground biomass estimates ranged from 191 g/m2

to 1,807 g/m2. No strong gradient pattern along the east-west axis of the marshes was 

observed for total aboveground biomass. A comparison of mean biomass vs. mean 

cover revealed a pattern in which cover peaked at about 900 g/m2 biomass, thus 

reducing the utility of mean cover as a predictor of mean biomass. Mean belowground 

estimates ranged from 116 g/m2 to 342 g/m2. A correlation analysis revealed no 

relationship between aboveground and belowground biomass. This may result from the 

nature of root distribution within the study area. Also, within plot variation of 

belowground biomass was very high. In future studies, a larger sample size will be 

needed to minimize the sample variation problem. 

Stenberg, J., M. Clark, and R. Conrow. 1997. Development of natural and planted vegetation 

and wildlife use in the Lake Apopka Marsh Flow-Way Demonstration Project: 1990–1994. 

Special Publication SJ98-SP4. Palatka, Fla.: St. Johns River Water Management 

District. 

PROJECT: Marsh Flow-Way Restoration (LA-3-301-M) 

EXECUTIVE SUMMARY

This report describes the results of a study of the early successional characteristics of 

plant and wildlife communities developing on the Lake Apopka Marsh Flow-Way 

Demonstration Project. The study was conducted to gain an understanding of possible 

biological community development patterns that might be expected on former 

agriculture lands undergoing restoration to wetland by the St. Johns River Water 
Appendix H 

St. Johns River Water Management District

513 

Management District. The study was conducted during the time period September 1990 

to March 1994. 

The Lake Apopka Marsh Flow-Way Demonstration Project was located along the 

northwest shore of Lake Apopka (28°40’ N latitude/80°39’ W longitude), approximately 

40 km northwest of Orlando, Florida. Prior to large-scale anthropogenic disturbance, 

the site probably had been a sawgrass and shrub wetland. A sawgrass and shrub 

wetland was inferred from observing aerial photographs taken during 1940. During the 

1940s and 1950s, conversion to agricultural use on the site, as well as, in the remaining 

Apopka Marsh was completed. The site was farmed until its purchase by the St. Johns 

River Water Management District in 1989. The flow-way project became operational 

and was flooded during November 1990. Flooding continued nearly uninterrupted 

through the end of the survey period (March 1994). Water level drawdowns occurred 

during June–August 1991 and spring 1993. 

At the initiation of the flow-way project, four distinct vegetation communities were 

present on the site. The eastern half of the southern flow-way cell (south marsh) 

contained a shallow emergent marsh with prominent species including, cattail (Typha 

latifolia), smartweed (Polygonum punctatum), pickerel weed (Pontederia cordata), 

arrowhead (Sagittaria lancifolia), water primrose (Ludwigia spp.), and southern waterhemp (Amaranthus australis). The western half of the southern cell (south marsh) was 

covered by an expanse of panic grass (Panicum dichotomiflorum) and water primrose 

(Ludwigia spp.) The northern cell (north marsh) contrasted sharply with that of the 

south. Most of the northern cell was covered by a continuous community of dogfennel 

(Eupatorium capilifolium). A narrow swath (~400m x 600m) adjacent to the western 

perimeter road was dominated by St. Augustine grass (Stenatophrum secondatum). 

Soil on the site was predominantly histosol with varying thickness. Shallowest organic 

soil depths were observed in the northeastern corner of the southern cell. A soil 

consisting of silts and clays was observed below less than 10 cm of histosol. With time, 

and the continual action of Lake Apopka phytoplankton sedimentation, an 

unconsolidated flocculent layer with greatest depths of about 35 cm was observed in the 

eastern south cell. 

The study was conducted using a multi-faceted approach. To test plant community 

successional patterns and the potential for manipulating these successional patterns 

sample plots and transects were established in the unmanipulated marsh (Natural 

Succession Transects) and in three areas containing planted, seeded, or mulched plots 

(Experimental Planting Sites).