FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION 

Division of Water Resource Management, Bureau of Watershed Management

SOUTHWEST DISTRICT • SARASOTA BAY–PEACE–MYAKKA BASINS 

TMDL Report 

Nutrient TMDL for the 

Winter Haven Southern Chain of Lakes

(WBIDs 1521, 1521D, 1521E, 1521F, 

1521G, 1521H, 1521J, 1521K) 

Kevin Petrus 

February 28, 2007 

 
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Acknowledgments 

This report could not have been accomplished without significant contributions from staff in the 

Florida Department of Environmental Protection’s (Department) Watershed Assessment 

Section. Aaron Lassiter prepared many of the tables and figures in the report. The Department 

also recognizes the support and assistance of the Southwest Florida Water Management 

District and city of Winter Haven staff, particularly their contributions towards understanding the 

issues, history, and processes at work in the Winter Haven Chain of Lakes watershed.

Editorial assistance provided by Jan Mandrup-Poulsen, Daryll Joyner, and Linda Lord. 

Map production assistance provided by Aaron Lassiter. 

For additional information on the watershed management approach and impaired waters 

in the Sarasota Bay, Peace River, and Myakka River (Sarasota Bay–Peace–Myakka) 

Basins, contact 

Tom Singleton 

Florida Department of Environmental Protection 

Bureau of Watershed Management 

Watershed Planning and Coordination Section 

2600 Blair Stone Road, Mail Station 3565 

Tallahassee, FL 32399-2400 

E-mail: thomas.singleton@dep.state.fl.us

Phone: (850) 245-8561; Suncom: 205-8461 

Fax: (850) 245-8434 

Access to all data used in the development of this report can be obtained by contacting

Kevin Petrus 

Florida Department of Environmental Protection 

Bureau of Watershed Management 

Watershed Assessment Section 

2600 Blair Stone Road, Mail Station 3555 

Tallahassee, FL 32399-2400 

E-mail: kevin.petrus@dep.state.fl.us

Phone: (850) 245-8459; Suncom: 205-8459 

Fax: (850) 245-8536 
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Contents 

Chapter 1: INTRODUCTION___________________________________1

1.1 Purpose of Report ________________________________________________1

1.2 Identification of Waterbodies _______________________________________1

1.3 Background _____________________________________________________4

Chapter 2: DESCRIPTION OF WATER QUALITY PROBLEM ________6

2.1 Statutory Requirements and Rulemaking History ______________________6

2.2 Information on Verified Impairment__________________________________6

Chapter 3. DESCRIPTION OF APPLICABLE WATER QUALITY 

STANDARDS AND TARGETS ______________________10

3.1 Classification of the Waterbody and Criteria Applicable to the TMDL_____10

3.2 Applicable Water Quality Standards and Numeric Water Quality 

Targets _______________________________________________________10

3.2.1 Interpretation of Narrative Nutrient Criterion _________________________10

Chapter 4: ASSESSMENT OF SOURCES_______________________12

4.1 Types of Sources________________________________________________12

4.2 Point Sources __________________________________________________12

4.2.1 NPDES Permitted Wastewater Facilities ___________________________12

4.2.2 Municipal Separate Storm Sewer System Permittees _________________12

4.3 Land Uses and Nonpoint Sources__________________________________13

4.3.1 Land Uses___________________________________________________13

4.3.2 Estimating Nonpoint Loadings ___________________________________13

Chapter 5: DETERMINATION OF ASSIMILATIVE CAPACITY_______16

5.1 Determination of Loading Capacity_________________________________16

5.2 Critical Conditions_______________________________________________19

Chapter 6: DETERMINATION OF THE TMDL ____________________21

6.1 Expression and Allocation of the TMDL _____________________________21

6.2 Load Allocation _________________________________________________22

6.3 Wasteload Allocation ____________________________________________23

6.3.1 NPDES Wastewater Discharges__________________________________23

6.3.2 NPDES Stormwater Discharges __________________________________23

6.4 Margin of Safety_________________________________________________23
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Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN 

DEVELOPMENT AND BEYOND _____________________24

7.1 Basin Management Action Plan____________________________________24

References _______________________________________________25

Appendices _______________________________________________26

Appendix A: Graphs of Chlorophyll a, Total Nitrogen, and Total 

Phosphorus Sampling Results for the Southern Chain’s Impaired 

Lakes_________________________________________________________26

Appendix B: Background Information on Federal and State Stormwater 

Programs _____________________________________________________38

List of Tables 

Table 2.1. Verified Impairments in the Winter Haven Chain of Lakes 

Waterbody Segments _____________________________________ 7

Table 2.2. Summary of Nutrient Assessment Results for the Winter 

Haven Chain of Lakes _____________________________________ 8

Table 4.1. Classification of Land Use Categories in the Winter Haven 

Chain of Lakes Watershed ________________________________ 15

Table 4.2. Total Phosphorus Loading Estimates to the Winter Haven 

Chain of Lakesa _________________________________________ 15

Table 5.1. Winter Haven Chain of Lakes TSI Values under Existing and 

70 Percent Total Phosphorus Load Reductiona _______________ 18

Table 5.2. Total Phosphorus Loadings to the Southern Chain’s Impaired 

Lakes Needed To Meet the TSI Threshold of 60 Unitsa _________ 18

Table 6.1a. TMDL Components by Year for Total Phosphorus in the 

Southern Chain of Lakes__________________________________ 22

Table 6.1b. TMDL Components by Day for Total Phosphorus in the 

Southern Chain of Lakes__________________________________ 22

List of Figures 

Figure 1.1. Location of the Winter Haven Chain of Lakes Waterbody 

Segments, and Major Geopolitical Features in the Sarasota 

Bay–Peace–Myakka Basins ________________________________ 2

Figure 1.2. Winter Haven Chain of Lakes Waterbody Segments and 

Monitoring Locations _____________________________________ 3

Figure 4.1. Principal Land Uses in the Winter Haven Chain of Lakes 

Watershed______________________________________________ 14

Figure 5.1. PLRG Study Model Results for the TSI for Each Load 

Reduction Scenario Tested________________________________ 19
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Web Sites 

Florida Department of Environmental Protection, Bureau of 

Watershed Management 

Total Maximum Daily Load (TMDL) Program 

http://www.dep.state.fl.us/water/tmdl/index.htm

Identification of Impaired Surface Waters Rule 

http://www.dep.state.fl.us/water/tmdl/docs/AmendedIWR.pdf

Florida STORET Program 

http://www.dep.state.fl.us/water/storet/index.htm

2006 305(b) Report 

http://www.dep.state.fl.us/water/tmdl/docs/2006_Integrated_Report.pdf

Criteria for Surface Water Quality Classifications 

http://www.dep.state.fl.us/water/wqssp/classes.htm

Water Quality Status Report for the Sarasota Bay–Peace–Myakka Basins 

http://www.dep.state.fl.us/water/basin411/nassau/status.html 

Allocation Technical Advisory Committee (ATAC) Report 

http://www.dep.state.fl.us/water/tmdl/docs/Allocation.pdf

U.S. Environmental Protection Agency, National STORET Program 

Region 4: Total Maximum Daily Loads in Florida 

http://www.epa.gov/region4/water/tmdl/florida/

National STORET Program 

http://www.epa.gov/storet/

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Chapter 1: INTRODUCTION 

1.1 Purpose of Report 

This report presents the Total Maximum Daily Load (TMDL) for total phosphorus to address the 

nutrient impairment for the Southern Chain of Lakes in the Winter Haven Chain of Lakes, 

including Lakes Cannon, Howard, Idylwild, Jessie, Lulu, May, Mirror, and Shipp. These eight 

lakes were verified as impaired for nutrients, using the methodology described in the 

Identification of Impaired Surface Waters Rule (IWR), Rule 62-303, Florida Administrative Code 

(F.A.C.), and were included on the Verified List of impaired waters for the Peace River Basin 

that was adopted by Secretarial Order in June 2005. This TMDL report establishes the 

allowable loadings to the watershed that would restore the lakes so that they meet the 

applicable water quality standards for nutrients. The TMDL process quantifies the amount of a 

pollutant that can be assimilated in a waterbody, identifies the sources of the pollutant, and 

recommends regulatory or other actions to be taken to achieve compliance with applicable 

water quality standards, based on the relationship between pollution sources and ambient water 

quality conditions.

The Winter Haven Chain of Lakes is one of 10 priority Surface Water Improvement and 

Management (SWIM) waterbodies designated by the Southwest Florida Water Management 

District (SWFWMD). For SWIM waterbodies, Florida water policy requires the water 

management districts to set and adopt pollutant load reduction goals (PLRGs) for pollutants of 

concern. In the Water Resource Implementation Rule (Rule 62-40, F.A.C.), PLRGs are defined 

as estimated numeric reductions in pollutant loadings needed to preserve or restore the 

designated uses of receiving bodies of water and maintain water quality consistent with 

applicable state standards. In 2005, the SWFWMD developed a revised PLRG for phosphorus 

to address the eutrophication of lakes throughout the watershed (McCary and Ross, 2005). The 

PLRG identified the phosphorus load reductions needed to achieve the Trophic State Index 

(TSI) target for the lakes in the Southern Chain, and the load reductions are the basis for the 

nutrient TMDLs for these 8 impaired lakes. 

1.2 Identification of Waterbodies 

The Winter Haven Chain of Lakes watershed is located in north-central Polk County, within and 

around the city of Winter Haven (Figure 1.1). The Winter Haven Chain of Lakes system is 

generally divided into the Northern Chain, consisting of 5 lakes, and the Southern Chain, 

consisting of 16 lakes (Figure 1.2). The watershed draining to the lakes is almost 32 square 

miles, and almost half of this area comprises water and wetlands. The Northern Chain lakes 

include Conine, Rochelle, Haines, Smart and Fannie. The Southern Chain lakes consist of 

Winterset, Eloise, Summit, Lulu, Roy, Shipp, May, Howard, Cannon, Blue, Mirror, Spring, 

Idylwild, Jessie, Mariana, and Hartridge. Lakes Blue and Mariana are only connected to the 

other lakes in the Southern Chain when seasonal high waters exceed the lake operational 

levels. 
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Figure 1.1. Location of the Winter Haven Chain of Lakes 

Waterbody Segments, and Major Geopolitical 

Features in the Sarasota Bay–Peace–Myakka 

Basins
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Figure 1.2. Winter Haven Chain of Lakes Waterbody 

Segments and Monitoring Locations 
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In the Northern Chain, water levels in Lakes Haines, Rochelle, Conine, and Smart fluctuate at 

the same level, since they are interconnected via man-made canals. Structure P-6, between 

Lakes Smart and Fannie, controls these lake levels. Lake Fannie is downstream of Structure 

P-6, and its elevation is controlled by Structure P-7. When water passes through Structure P-7, 

it eventually flows into the Peace Creek Drainage Canal. At high water levels, water from the 

Southern Chain can enter the Northern Chain via a weir structure that allows flow from the east 

side of Lake Hartridge to the west side of Lake Conine. 

In the Southern Chain, water levels are related via a series of interconnecting canals. As 

mentioned above, Lakes Blue and Mariana are connected to the other lakes only during wet 

periods. The Southern Chain discharges from a structure on the southern side of Lake Lulu that 

controls the water levels of all the lakes in the Southern Chain (except Blue and Mariana). 

Discharge from this structure can be controlled to regulate lake levels in the Southern Chain. 

Flows out of Lake Lulu enter the Wahneta Farms Drainage Canal, which eventually flows into 

the Peace Creek Drainage Canal just north of Lake Garfield. 

For assessment purposes, the Florida Department of Environmental Protection (Department) 

has divided the Upper Peace River Planning Unit into water assessment polygons with a unique 

waterbody identification (WBID) number for each waterbody or waterbody segment. The 

Winter Haven Chain of Lakes watershed includes the 21 lake WBIDs in the Northern and 

Southern Chain. The 8 lake segments in the Southern Chain, which were placed on the Verified 

List for nutrient impairment, are the primary subjects of this TMDL report. Figure 1.2 shows the 

watershed, as well as the locations of the water quality monitoring stations and control 

structures discussed in this report. 

1.3 Background 

This report was developed as part of the Department’s watershed management approach for 

restoring and protecting state waters and addressing TMDL Program requirements. The 

watershed approach, which is implemented using a cyclical management process that rotates 

through the state’s 52 river basins over a 5-year cycle, provides a framework for implementing 

the TMDL Program–related requirements of the 1972 federal Clean Water Act and the 1999 

Florida Watershed Restoration Act (FWRA), Chapter 99-223, Laws of Florida. 

A TMDL represents the maximum amount of a given pollutant that a waterbody can assimilate 

and still meet water quality standards, including its applicable water quality criteria and its 

designated uses. TMDLs are developed for waterbodies that are verified as not meeting their 

water quality standards. They provide important water quality restoration goals that will guide 

restoration activities. 

This TMDL report will be followed by the development and implementation of a Basin 

Management Action Plan, or BMAP, to reduce the amount of nutrients that caused the verified 

impairment of lakes in the watershed. These activities will depend heavily on the active 

participation of the SWFWMD, Polk County, local governments, local businesses, and other 

stakeholders. The Department will work with these organizations and individuals to undertake 

or continue reductions in the discharge of pollutants and achieve the established TMDLs. 

Work has already begun to identify and implement projects that would be components of a 

BMAP. The SWFWMD, in cooperation with the city of Winter Haven, has begun to implement 

projects designed to reduce nutrient loadings to the lakes. The SWFWMD has funded several 
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stormwater management projects, a sediment removal feasibility study through the SWIM 

Program, and a water quality management plan. Stormwater management projects include the 

construction of stormwater treatment systems along Lakes May, Lulu, Hartridge, and Howard. 

The sediment removal feasibility study will predict the water quality benefits of removing 

sediments from Lakes May, Shipp, and Lulu, where sediment accumulation has occurred due to 

historical point and nonpoint source pollutant discharges, and estimate the costs of 

implementing the project. The water quality management plan would identify action plans to 

improve water quality and provide specific recommendations for projects that could be used to 

meet the TMDLs and PLRGs. 
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Chapter 2: DESCRIPTION OF WATER QUALITY 

PROBLEM 

2.1 Statutory Requirements and Rulemaking History 

Section 303(d) of the federal Clean Water Act requires states to submit to the U.S. 

Environmental Protection Agency (EPA) a list of surface waters that do not meet applicable 

water quality standards (impaired waters) and establish a TMDL for each pollutant causing the 

impairment of the listed waters on a schedule. The Department has developed these lists, 

commonly referred to as 303(d) lists, since 1992. The list of impaired waters in each basin is 

also required by the FWRA (Subsection 403.067[4], Florida Statutes [F.S.]), and the list is 

amended annually to include updates for each basin statewide. 

Florida’s 1998 303(d) list included 84 waterbodies in the Sarasota Bay–Peace–Myakka Basins . 

However, the FWRA (Section 403.067, F.S.) stated that all previous Florida 303(d) lists were for 

planning purposes only and directed the Department to develop, and adopt by rule, a new 

science-based methodology to identify impaired waters. After a long rulemaking process, the 

Environmental Regulation Commission adopted the new methodology as Rule 62-303, F.A.C. 

(Identification of Impaired Surface Waters Rule, or IWR), in April 2001. The list of waters for 

which impairments have been verified using the methodology in the IWR is referred to as the 

Verified List. 

2.2 Information on Verified Impairment 

The Department used the IWR to assess water quality in the Winter Haven Chain of Lakes and 

verified the impairments for nutrients in the 12 lakes shown in Table 2.1. Table 2.2 summarizes 

the nutrient assessment results, based on annual average TSI values, for all the Winter Haven 

Chain of Lakes using data collected during the verification period (January 1997 to June 2004) 

and planning period (January 1992 to December 2001). The TSI, a calculation based on 

nutrient and chlorophyll a concentrations, is the primary means of assessing nutrient impairment 

in lakes. 

The IWR listing methodology has two TSI thresholds that are typically applied, depending on the 

annual mean color in lake water. Lakes or lake segments are placed on the Verified List if the 

annual mean TSI in any one year exceeds 60 when the mean annual color is greater than 40 

platinum cobalt units (PCUs), or if the TSI exceeds 40 when the mean annual color is less than 

or equal to 40 PCUs. Additionally, the IWR allows for alternative, site-specific thresholds that 

more accurately reflect conditions beyond which an imbalance in flora or fauna occurs, to be 

used in place of the default threshold values in the rule. As explained in Chapter 3, the TSI 

threshold of 60 is used as the target to develop the nutrient TMDL for each lake. This 

alternative threshold is based on paleolimnological research performed on lakes in the Winter 

Haven Chain, indicating that the natural background condition of the lakes is a TSI above 40, 

even though mean annual color values are frequently less than 40 PCUs. The initial Verified 

List also included Lakes Winterset, Eloise, Hartridge, and Fannie because at least one annual 

average TSI exceeded the default threshold value of 40 in the verified period. These 4 lakes 

were subsequently removed from the Verified List because none of the annual average TSI 

values exceeded the alternative threshold of 60 during the verification period.
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Table 2.1. Verified Impairments in the Winter Haven Chain 

of Lakes Waterbody Segments 

WBID Waterbody Segment Chain 

Parameter 

Causing 

Impairment 

Priority 

for TMDL 

Development 

Projected Year 

for TMDL 

Development 

1521H Lake Cannon Southern Nutrients (TSI) High 2004 

1521F Lake Howard Southern Nutrients (TSI) High 2004 

1521K Lake Jessie Southern Nutrients (TSI) High 2004 

1521 Lake Lulu Southern Nutrients (TSI) High 2004 

1521E Lake May Southern Nutrients (TSI) High 2004 

1521G Lake Mirror Southern Nutrients (TSI) High 2004 

1521D Lake Shipp Southern Nutrients (TSI) High 2004 

1488C Lake Haines Northern Nutrients (TSI) High 2004 

1488A Lake Smart Northern Nutrients (TSI) High 2004 

1521J Lake Idylwild Southern Nutrients (TSI) Medium 2009 

1488U Lake Conine Northern Nutrients (TSI) Medium 2009 

1488B Lake Rochelle Northern Nutrients (TSI) Medium 2009 

The Polk County Natural Resources Division, Florida LakeWatch, and SWFWMD collected most 

of the lake data used in the assessment. Appendix A presents graphs of the individual 

chlorophyll a, total nitrogen, and total phosphorus sampling results for each of the eight 

Southern Chain of Lakes impaired for nutrients. 

As part of the listing process, the Department attempts to identify the limiting nutrient or 

nutrients for the impaired waterbody. The limiting nutrient, generally nitrogen or phosphorus, is 

defined as the nutrient that limits plant growth when it is not available in sufficient quantities. A 

limiting nutrient is a chemical that is necessary for algal and plant growth, but available in 

quantities smaller than those needed for algae, represented by chlorophyll a, and macrophytes 

to grow. Once the limiting nutrient in a waterbody is exhausted, algae stop growing. If more of 

the limiting nutrient is added, larger algal populations will result until nutrients or other 

environmental factors again limit their growth. 
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Annual Average TSI

WBID Waterbody Segment Chain 

IWR 

Assessment 

Status Based 

on TSI for 

Nutrients 

TMDL 

Yeara 

TN/TP 

Ratio 

Median 1992 1993 1994 1995 1996 1997 1998 1999 2000 20

1521Q Lake Blue Southern Planning List 20.0 68.5 64.3 64.2 - - - - - - - 

1521H Lake Cannon Southern Impaired 2004 22.0 63.0 62.2 59.5 66.7 65.1 62.3 62.7 56.9 60.8 62

1521B Lake Eloise Southern Not Impaired 2004 38.3 - - - 63.7 - 55.6 - - - - 

1521I Lake Hartridge Southern Not Impaired 2009 26.6 - - - - - 51.4 - 45.5 - - 

1521F Lake Howard Southern Impaired 2004 45.6 67.5 63.4 62.5 65.2 63.3 65.5 - 57.3 - - 

1521J Lake Idylwild Southern Impaired 2009 22.4 - - - - - 58.9 61.8 58.8 - - 

1521K Lake Jessie Southern Impaired 2004 19.4 63.6 - - 64.6 62.2 61.1 62.9 59.0 - - 

1521 Lake Lulu Southern Impaired 2004 24.0 64.1 61.4 65.4 63.3 64.6 63.0 63.3 57.2 65.0 66

1521L Lake Marianna Southern Not Impaired 35.5 - 55.5 - - - - - - - - 

1521E Lake May Southern Impaired 2004 23.0 - - - - - 64.1 67.0 59.1 - - 

1521G Lake Mirror Southern Impaired 2004 43.0 - - - - - - - - - - 1521O Lake Roy Southern Insufficient Data 38.7 - - - - - - - - - - 

1521D Lake Shipp Southern Impaired 2004 40.2 - - - - - 70.4 - 64.9 75.6 72

1521M Lake Summit Southern Insufficient Data 23.1 - - - - - - - - - - 

1521A Lake Winterset Southern Not Impaired 2009 36.9 - - - - - - - 45.9 - - 

1521G1 Spring Lake Southern Insufficient Data 25.8 - - - - - - - - - - 

1488U Lake Conine Northern Impaired 2009 16.9 - 75.6 78.6 68.3 71.0 66.5 63.3 58.4 58.6 63

14882 Lake Fannie Northern Not Impaired 2009 25.7 58.4 - - - 59.1 - - 49.0 - - 

1488C Lake Haines Northern Impaired 2004 21.5 71.0 75.5 76.3 69.1 75.4 70.2 65.8 65.5 62.2 59

1488B Lake Rochelle Northern Impaired 2009 24.0 62.5 - - 62.2 63.4 61.6 62.3 58.1 58.5 - 1488A Lake Smart Northern Impaired 2004 24.7 - - - - - 64.9 66.6 59.3 60.0 - 

a The year for TMDL development is based on the schedule from the 1998 303(d) list. 

- – Insufficient data available to calculate an annual average TSI value. 
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Determining the limiting nutrient in a waterbody can be accomplished by calculating the ratio of 

nitrogen-to-phosphorus concentrations in the waterbody. Water column ratios of total nitrogen 

(TN) to total phosphorus (TP) of less than 10 indicate nitrogen limitation, TN to TP ratios 

between 10 and 30 indicate colimitation by nitrogen and phosphorus, and TN to TP ratios 

greater than 30 indicate phosphorus limitation. Based on the data collected during the verified 

period, the Winter Haven Chain of Lakes median values of the individual TN to TP ratios for 

each lake indicate that the lakes are either phosphorus limited or colimited (Table 2.2). Of the 

lakes on the Verified List, Lakes Mirror, Howard, and Shipp in the Southern Chain are 

phosphorus limited, and the rest of the lakes are colimited by nitrogen and phosphorus. While 

many of the lakes in the watershed are colimited by nitrogen and phosphorus, the Department 

agrees with the PLRG study that the existing evidence suggests that the Winter Haven Chain of 

Lakes are mostly phosphorus-limited systems, and this document only establishes TMDLs for 

phosphorus. 

In addition to causing the excessive growth of algae, the nutrient enrichment of a waterbody can 

lead to widely varying dissolved oxygen (DO) levels and low DO concentrations in bottom 

waters. Algal populations produce oxygen as a result of photosynthesis during daylight hours 

and consume oxygen due to respiration at night and at water depths where light does not 

penetrate. Additionally, a portion of the dead algal population becomes part of the organic 

material that will be broken down by microbes and in the process consumes DO in the water 

column and sediments. Reductions in algal biomass through the control of nutrient loads are 

expected to result in higher average DO concentrations and smaller DO variation in surface 

waters. 
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Chapter 3. DESCRIPTION OF APPLICABLE WATER 

QUALITY STANDARDS AND TARGETS 

3.1 Classification of the Waterbody and Criteria Applicable to 

the TMDL 

Florida’s surface waters are protected for five designated use classifications, as follows: 

Class I Potable water supplies 

Class II Shellfish propagation or harvesting 

Class III Recreation, propagation, and maintenance of a healthy, wellbalanced population of fish and wildlife 

Class IV Agricultural water supplies 

Class V Navigation, utility, and industrial use (there are no state 

waters currently in this class) 

The Winter Haven Chain of Lakes are Class III fresh waterbodies, with a designated use of 

recreation, propagation, and maintenance of a healthy, well-balanced population of fish and 

wildlife. The Class III water quality criterion applicable to the observed impairment addressed in 

this TMDL is the narrative nutrient criterion. 

3.2 Applicable Water Quality Standards and Numeric Water 

Quality Targets 

3.2.1 Interpretation of Narrative Nutrient Criterion 

Florida’s nutrient criterion is narrative only—nutrient concentrations of a body of water shall not 

be altered so as to cause an imbalance in natural populations of aquatic flora or fauna. 

Accordingly, a nutrient-related target was needed to represent levels at which an imbalance in 

flora or fauna is expected to occur. While the IWR provides a threshold for nutrient impairment 

for lakes based on annual average TSI levels, these thresholds are not standards and need not 

be used as the nutrient-related water quality target for TMDLs. In fact, in recognition that the 

IWR thresholds were developed using statewide average conditions, the IWR (Section 62-

303.450, F.A.C.) specifically allows the use of alternative, site-specific thresholds that more 

accurately reflect conditions beyond which an imbalance in flora or fauna occurs in a waterbody. 

In translating the narrative nutrient criterion for this TMDL, the TSI target set by the SWFWMD, 

which is derived from the conclusions of a paleolimnological study of lakes in the Winter Haven 

Chain, was used as the site-specific threshold to address the lakes’ nutrient impairment. 

Researchers from the University of Florida conducted a paleolimnological investigation of 

sediment cores from five lakes (Lakes Conine, Haines, Hartridge, Howard, and May) in the 

Winter Haven Chain of Lakes (Whitmore and Brenner, 1995). The researchers indicated that 

qualitative interpretations show similar patterns of historical change in all five lakes. The 

deepest, predisturbance samples (nominally 1860) in all the lakes studied showed the 

dominance of planktonic species that are distinctive indicators of mesotrophic to eutrophic 

conditions. The study concluded that, given the predisturbance conditions in the lakes, the 

maximum improvement in current water quality that is feasible would result in mesotrophic to 
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eutrophic conditions, the elimination of cyanobacterial blooms, and the re-establishment of 

summer populations of planktonic diatoms. Mesotrophic to eutrophic conditions are typically 

associated with TSI values in the range of 50 to 60. Based on the study results, the SWFWMD 

set a TSI target of 60 for the lakes for PLRG development (SWFWMD, 1998), and the 

Department used this target as the target for the TMDLs. 
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Chapter 4: ASSESSMENT OF SOURCES 

4.1 Types of Sources 

An important part of the TMDL analysis is the identification of pollutant source categories, 

source subcategories, or individual sources of the pollutant of concern in the watershed and the 

amount of pollutant loading contributed by each of these sources. Sources are broadly 

classified as either “point sources” or “nonpoint sources.” Historically, the term “point sources” 

has meant discharges to surface waters that typically have a continuous flow via a discernable, 

confined, and discrete conveyance, such as a pipe. Domestic and industrial wastewater 

treatment facilities (WWTFs) are examples of traditional point sources. In contrast, the term 

“nonpoint sources” was used to describe intermittent, rainfall-driven, diffuse sources of pollution 

associated with everyday human activities, including runoff from urban land uses, agriculture, 

silviculture, and mining; discharges from failing septic systems; and atmospheric deposition. 

However, the 1987 amendments to the Clean Water Act redefined certain nonpoint sources of 

pollution as point sources subject to regulation under the EPA’s National Pollutant Discharge 

Elimination System (NPDES) Program. These nonpoint sources included certain urban 

stormwater discharges, including those from local government master drainage systems, 

construction sites over five acres, and a wide variety of industries (see Appendix B for 

background information on the federal and state stormwater programs). 

To be consistent with Clean Water Act definitions, the term “point source” is used to describe 

traditional point sources (such as domestic and industrial wastewater discharges) and 

stormwater systems requiring an NPDES stormwater permit when allocating pollutant load 

reductions required by a TMDL. However, the methodologies used to estimate nonpoint source 

loads do not distinguish between NPDES stormwater discharges and non-NPDES stormwater 

discharges, and as such, this chapter does not make any distinction between the two types of 

stormwater. 

4.2 Point Sources 

4.2.1 NPDES Permitted Wastewater Facilities 

There are no NPDES-permitted wastewater treatment facilities that discharge to surface waters 

in the Winter Haven Chain of Lakes watershed. 

4.2.2 Municipal Separate Storm Sewer System Permittees 

Municipal separate storm sewer systems (MS4s) may also discharge pollutants to waterbodies 

in response to storm events. To address stormwater discharges, the EPA developed the 

NPDES stormwater permitting program in two phases. Phase I, promulgated in 1990, 

addresses large and medium-size MS4s located in incorporated areas and counties with 

populations of 100,000 or more. Phase II permitting began in 2003. Regulated Phase II MS4s 

are defined in Section 62-624.800, F.A.C., and typically cover urbanized areas serving 

jurisdictions with a population of at least 10,000 or discharging into Class I or Class II waters, or 

into Outstanding Florida Waters. 

The stormwater collection systems in the Winter Haven Chain of Lakes watershed, which are 

owned and operated by Polk County in conjunction with the Florida Department of 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

13

Transportation (FDOT), District 1, are covered by a Phase I MS4 permit. The watershed falls 

under the Polk County Phase I MS4 Permit (Number FLS000015). The cities of Winter Haven 

and Lake Alfred are copermittees and own and operate many of the MS4 areas for the portions 

of their jurisdictions located within the watershed. 

4.3 Land Uses and Nonpoint Sources 

Nutrient loading from urban areas is most often attributable to multiple sources, including 

stormwater runoff, leaks and overflows from sanitary sewer systems, illicit discharges of sanitary 

waste, runoff from the improper disposal of waste materials, leaking septic systems, and 

domestic animals. Part of the surface runoff loads come from atmospheric deposition that falls 

directly onto the land surface and then is washed off into surface waters during rain events. 

Onsite sewage treatment and disposal systems (OSTDSs), including septic tanks, are 

commonly used where providing central sewer is not cost-effective or practical. When properly 

sited, designed, constructed, maintained, and operated, OSTDSs are a safe means of disposing 

of domestic waste. The effluent from a well-functioning OSTDS is comparable to secondarily 

treated wastewater from a sewage treatment plant. When not functioning properly, however, 

OSTDSs can be a source of nutrients (nitrogen and phosphorus), pathogens, and other 

pollutants to both ground water and surface water. 

As of 2004, Polk County has approximately 112,848 septic systems (Florida Department of 

Health, 2005). This total does not reflect systems removed from service going back to 1970. 

The Department does not have information on the percentage of the population using septic 

systems in Polk County, nor does it have estimates of countywide failure rates to determine the 

daily discharge of wastewater from septic tanks. 

4.3.1 Land Uses 

The spatial distribution and acreage of different land use categories were identified using the 

SWFWMD’s 1999 land use coverage (scale 1:40,000) contained in the Department’s 

geographic information system (GIS) library (Department, June 2004). The Winter Haven Chain 

of Lakes watershed covers 20,257 acres, or approximately 32 square miles. Land use 

categories in the watershed, aggregated using the Level 1 1999 Florida Land Use and Cover 

Classification System (FLUCCS), are tabulated in Table 4.1. The predominant Level I land use 

in the watershed is urban and built-up, which comprises 38 percent of the area. The next 

largest area is water, which makes up 37 percent of the watershed area. Figure 4.1 shows the 

principal land uses in the watershed. 

4.3.2 Estimating Nonpoint Loadings 

The PLRG study report, which is the basis for this TMDL, included loading estimates from 

surface runoff and ground water (McCary and Ross, 2005). The study estimated total 

phosphorus loads from watershed runoff using the Storm Water Management Model (SWMM) 

and from ground water using the U.S. Geological Survey MODFLOW Program (McCary and 

Ross, 2005). Table 4.2 presents the 10-year average (1990 to 1999) model load results for 

each lake. The loading estimates show that watershed runoff contributes about 2,800 kilograms 

(kg)/year of total phosphorus in the Southern Chain and almost 500 kg/year in the Northern 

Chain. Ground water contributes another 123 kg/year of total phosphorus in the Southern 

Chain and 135 kg/year in the Northern Chain. A larger proportion of the load to the Northern 

Chain of Lakes is derived from ground water, which makes up 29 percent of the total load, 

compared with only 4 percent of the total load to the Southern Chain of Lakes. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

14 

Figure 4.1. Principal Land Uses in the Winter Haven Chain 

of Lakes Watershed 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

15

Table 4.1. Classification of Land Use Categories in the 

Winter Haven Chain of Lakes Watershed 

Code Land Use Acreage % 

of Total 

1000 Urban Open 3,003 15 

1100 Residential Low Density < 2 Dwelling Units/Acre 412 2 

1200 Residential Med Density 2 – 5 Dwelling Units/Acre 3,489 17 

1300 Residential High Density 6 or more Dwelling Units/Acre 794 4 

2000 Agriculture 2,382 12 

3000 Rangeland 180 1 

4000 Upland Forests 509 3 

5000 Water 7,459 37 

6000 Wetlands 1,556 8 

8000 Transportation, Communication, and Utilities 473 2 

Totals 20,257 100 

Table 4.2. Total Phosphorus Loading Estimates to the 

Winter Haven Chain of Lakesa

Total P (kg/year) 

Lake Chain 

Surface 

Runoff 

Ground Water 

Inflow 

Total 

Existing 

Load 

Winterset Southern 87.0 7.8 94.8 

Eloise Southern 181.6 10.1 191.7 

Summit Southern 40.3 1.9 42.2 

Lulu Southern 158.3 9.0 167.3 

Roy Southern 69.6 3.1 72.7 

Shipp Southern 228.5 12.9 241.4 

May Southern 180.3 4.5 184.8 

Howard Southern 322.1 14.3 336.4 

Cannon Southern 272.2 8.0 280.2 

Blue Southern 152.0 3.4 155.4 

Mirror Southern 68.4 2.2 70.6 

Spring Southern 36.8 1.4 38.2 

Idylwild Southern 100.1 3.8 103.9 

Jessie Southern 239.5 14.6 254.1 

Marianna Southern 440.4 17.0 457.4 

Hartridge Southern 214.7 9.2 223.9 

Total 2,792 123 2,915 

Conine Northern 154.1 15.0 169.1 

Rochelle Northern 69.9 22.3 92.2 

Haines Northern 154.7 41.6 196.3 

Smart Northern 35.6 13.9 49.5 

Fannie Northern 56.3 42.1 98.4 

Total 471 135 606 a

 Loads obtained from model simulations in McCary and Ross, 2005. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

16 

Chapter 5: DETERMINATION OF ASSIMILATIVE 

CAPACITY 

5.1 Determination of Loading Capacity 

The TMDL development process identifies the maximum allowable TP loading to the Southern 

Chain of Lakes watershed, so that the lakes will meet nutrient water quality criteria and maintain 

their function and designated use as Class III waters. The Winter Haven Chain of Lakes is one 

of the 10 priority SWIM waterbodies designated by the SWFWMD. For SWIM waterbodies, 

Florida water policy requires the water management districts to set and adopt PLRGs for 

pollutants of concern. In the Water Resource Implementation Rule (Rule 62-40, F.A.C.), 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 standards. In 2005, the SWFWMD developed a revised PLRG for total 

phosphorus to address lake eutrophication throughout the watershed, and this PLRG serves as 

the basis for the nutrient TMDLs for the verified impaired lakes in the Southern Chain. This 

chapter summarizes the process used to develop the revised PLRG; the details of the study can 

be found in McCary and Ross (2005). 

The PLRG study entailed gathering data and information to develop a watershed runoff and 

ground water model that was then linked to a surface water model to simulate surface water 

quality for each of the 21 lakes in the Winter Haven Chain of Lakes watershed. A spreadsheet 

model was also developed to account for channel flows between the lakes. Model simulation 

was performed for the period from 1990 to 1999. The modeling included the setup of the 

SWMM to account for surface runoff volume and nutrient loadings, and the MODFLOW 

Program to account for ground water volume and nutrient loadings. The loads generated from 

the SWMM and MODFLOW model simulations, as well as the transport between lakes obtained 

from the spreadsheet model, were then entered into the Water Quality Analysis Simulation 

Program (WASP) model that simulated water quality in each lake. Two WASP models were 

developed, one for the Northern Chain and one for the Southern Chain, as there are limitations 

in the number of segments (i.e., lakes) that can be entered into WASP. 

Since this study is based on nutrient loading, the eutrophication module (EUTRO) in WASP was 

used to simulate the eutrophication processes in the lakes. For this study, simple eutrophication 

kinetics were used to model lake water quality. These simulate the growth and decay of 

phytoplankton interacting with one of the nutrient cycles. Growth can be limited by the 

availability of inorganic nitrogen or inorganic phosphorus, and light. For this study, growth 

would be limited by inorganic phosphorus and light. The lakes in the watershed are either 

limited by phosphorus or colimited by nitrogen and phosphorus. For the PLRG study, it was 

assumed that the lakes as a whole are phosphorus limited. 

Water quantity calibration included comparing model results with the observed lake stage. 

Phosphorus and chlorophyll a concentration values were used for water quality calibration. A 

spreadsheet model was developed to simulate flows between the lakes and to calibrate model 

lake stage to measured lake stage. Calibration was accomplished by adjusting leakage values 

from the lakes to the Floridan aquifer, so that modeled lake stages were calibrated to measured 

lake stages. For the water quality calibration, once all known flows, loads, and parameter 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

17

values were entered, system constants were chosen within the range of recommended values, 

as specified by WASP, that gave the best overall performance and match to measured data. In 

most cases, phosphorus was used for calibration; however, for Lakes Howard and Jessie, 

chlorophyll a data were used because of concerns over the measured phosphorus values. Final 

calibration was accomplished by adjusting the phosphorus settling rate for each individual lake. 

Once the models were calibrated, a series of design scenarios was simulated to determine the 

effect of phosphorus load reductions on the lakes’ trophic level, measured by the TSI. The 

scenarios were based on total phosphorus load reductions of 10, 20, 30, 50, and 70 percent 

throughout the watershed over the 10-year period from 1990 to 1999. The model results show 

that less than a 70 percent reduction in the total load is needed to meet the TSI target of 60 for 

the lakes in the Southern Chain, except for Lake Blue (Table 5.1). However, Lake Blue was not 

assessed for nutrients during the verified period because there were insufficient data to assess 

for nutrient impairment following the IWR methodology. 

To derive a TMDL for each impaired lake in the Southern Chain, the TSI model results from the 

design scenarios were plotted with the phosphorus load reduction increments to generate a line 

fitted to the model results for each lake, as presented in Figure 5.1. The load reductions 

necessary to meet a TSI of 60 for each lake were obtained from the location where the percent 

reductions met the TSI threshold on the graph. The load reductions needed to achieve a TSI of 

60 in each lake varied between 22.5 percent for Lake Mirror to 60 percent for Lake Shipp. 

Table 5.2 presents the existing total phosphorus loads, as well as the percent reduction and 

associated loadings for each impaired lake to achieve the TSI threshold of 60. 

For 3 of the 5 lakes in the Northern Chain (Lakes Conine, Haines, and Smart), phosphorus load 

reductions greater than 70 percent are needed to achieve a TSI of 60 (Table 5.1). The PLRG 

study report indicates that the lack of significant improvements in TSI values for Northern Chain 

lakes is most likely due to the dependence of the Northern Chain on ground water inflows. 

Additionally, since all the lakes in the Northern Chain are colimited, reductions in nitrogen loads 

may also be needed to effect lake eutrophication. The 70 percent load reduction for the 

Northern Chain shows the lake TSIs would be reduced by at least 6 TSI units, compared with 

the existing condition. As the PLRG study does not identify the phosphorus load reduction 

needed to meet a TSI of 60 for all the verified impaired lakes in the Northern Chain, TMDLs are 

not proposed for the Northern Chain of Lakes. 

The Department identified the following additional studies that are needed to better define the 

relationship between nutrient loadings and lake eutrophication: 

• Estimate loadings from atmospheric deposition directly on the lake surfaces, since water 

covers a considerable area of the watershed, 

• Determine the area of households not connected to wastewater treatment plants and 

estimate the septic system loading to the watershed, 

• Include sediment nutrient exchanges rates in the modeling, as there are some lakes 

where the internal loading from sediments is expected to be considerable, and 

• Account for the effects of nitrogen limitation on phytoplankton growth, as the nitrogen-tophosphorus ratios indicate many of the lakes are colimited. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

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Table 5.1. Winter Haven Chain of Lakes TSI Values under 

Existing and 70 Percent Total Phosphorus Load 

Reductiona

Existing Total P Load Total P Load Reduced by 70% 

Lake Chain 

Total P TSI Chlorophyll a TSI Average 

TSI Total P TSI Chlorophyll a TSI Average TSI 

Winterset Southern 59.2 50.4 54.8 37.1 32.5 34.8 

Eloise Southern 69.1 58.5 63.8 45.4 41.8 43.6 

Summit Southern 62.4 55.2 58.8 38.4 37.4 37.9 

Lulu Southern 76.8 68.4 72.6 49.4 51.1 50.3 

Roy Southern 66.2 58.0 62.1 38.9 38.4 38.7 

Shipp Southern 83.0 72.3 77.7 54.8 54.7 54.8 

May Southern 78.7 69.8 74.3 50.5 52.4 51.5 

Howard Southern 82.0 71.3 76.7 53.8 53.4 53.6 

Cannon Southern 78.2 67.3 72.8 50.0 49.1 49.6 

Blue Southern 94.2 78.7 86.5 65.8 61.2 63.5 

Mirror Southern 68.2 61.8 65.0 40.2 42.8 41.5 

Spring Southern 59.5 54.5 57.0 31.8 33.8 32.8 

Idylwild Southern 72.8 66.0 69.4 44.6 48.1 46.4 

Jessie Southern 75.5 67.5 71.5 47.3 49.4 48.4 

Marianna Southern 64.8 60.9 62.9 36.7 42.7 39.7 

Hartridge Southern 65.7 60.2 63.0 37.8 40.9 39.4 

Conine Northern 79.0 68.9 74.0 70.8 63.8 67.3 

Rochelle Northern 70.9 62.5 66.7 57.4 53.9 55.7 

Haines Northern 80.7 68.4 74.6 65.7 59.3 62.5 

Smart Northern 73.5 64.8 69.2 65.9 60.1 63.0 

Fannie Northern 70.5 61.6 66.1 60.9 55.5 58.2 a

 TSI values from model simulations in McCary and Ross, 2005. 

Table 5.2. Total Phosphorus Loadings to the Southern 

Chain’s Impaired Lakes Needed To Meet the TSI 

Threshold of 60 Unitsa 

Lake 

Existing 

Total P 

Surface 

Runoff 

(kg/year) 

Existing Total 

P Ground 

Water Inflow 

(kg/year) 

Existing 

Total P 

Load 

(kg/year) 

% Reduction to 

Meet TSI 

Threshold 

Total P Load to 

Meet TSI 

Threshold 

(kg/year) 

Cannon 272.2 8.0 280.2 49.0 142.9 

Howard 322.1 14.3 336.4 57.5 143.0 

Idylwild 100.1 3.8 103.9 38.0 64.4 

Jessie 239.5 14.6 254.1 45.0 139.8 

Lulu 158.3 9.0 167.3 50.0 83.7 

May 180.3 4.5 184.8 52.5 87.8 

Mirror 68.4 2.2 70.6 22.5 54.7 

Shipp 228.5 12.9 241.4 60.0 96.6 a

 Loads obtained from model simulations in McCary and Ross, 2005.
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

19

Winter Haven Southern Chain of Lakes 

TSI (average) vs. TP Load Reduction 

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60 70 80

Total Phosphorus Percent Reduction

Lake TSI (average) 

Cannon Howard Idylwild Jessie

Lulu May Mirror Shipp

Figure 5.1. PLRG Study Model Results for the TSI for Each 

Load Reduction Scenario Tested 

The city of Winter Haven and the SWFWMD are funding a project to perform additional work to 

better understand the relationships between pollutant loads and lake water quality. This effort 

will address all sources of pollution, including stormwater, point sources, sediments, ground 

water, dry fall, and septic tanks. The project involves incorporating existing information, 

obtaining additional data, and using the previously developed nutrient budget and Linked 

Watershed/Waterbody Model to model the lakes. It is anticipated that the project will be 

completed by the end of 2008 and may result in revisions to the existing TMDLs and the 

establishment of TMDLs to meet the TSI target of 60 for the impaired lakes in the Northern 

Chain. 

5.2 Critical Conditions

The Winter Haven Chain of Lakes TMDL was based on annual average conditions rather than 

critical/seasonal conditions because of the following: 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

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(a) The methodology used to determine assimilative capacity does not lend itself very well 

to short-term assessments, 

(b ) The net change in overall primary productivity, which is better addressed on an annual 

basis, is generally a better indicator of an imbalance in flora or fauna, and 

(c) The methodology used to determine impairment is based on an annual average and 

requires data from all four quarters of a calendar year. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

21

Chapter 6: DETERMINATION OF THE TMDL 

6.1 Expression and Allocation of the TMDL 

The objective of a TMDL is to provide a basis for allocating acceptable loads among all of the 

known pollutant sources in a watershed so that appropriate control measures can be 

implemented and water quality standards achieved. A TMDL is expressed as the sum of all 

point source loads (wasteload allocations, or WLAs), nonpoint source loads (load allocations, or 

LAs), and an appropriate margin of safety (MOS), which takes into account any uncertainty 

concerning the relationship between effluent limitations and water quality: 

TMDL = ∑ WLAs + ∑ LAs + MOS

As discussed earlier, the WLA is broken out into separate subcategories for wastewater 

discharges and stormwater discharges regulated under the NPDES Program: 

TMDL ≅ ∑ WLAswastewater + ∑ WLAsNPDES Stormwater + ∑ LAs + MOS 

It should be noted that the various components of the revised TMDL equation may not sum up 

to the value of the TMDL because (a) the WLA for NPDES stormwater is typically based on the 

percent reduction needed for nonpoint sources and is also accounted for within the LA, and (b) 

TMDL components can be expressed in different terms (for example, the WLA for stormwater is 

typically expressed as a percent reduction, and the WLA for wastewater is typically expressed 

as mass per day). 

WLAs for stormwater discharges are typically expressed as “percent reduction” because it is 

very difficult to quantify the loads from MS4s (given the numerous discharge points) and to 

distinguish loads from MS4s from other nonpoint sources (given the nature of stormwater 

transport). The permitting of stormwater discharges also differs from the permitting of most 

wastewater point sources. Because stormwater discharges cannot be centrally collected, 

monitored, and treated, they are not subject to the same types of effluent limitations as 

wastewater facilities, and instead are required to meet a performance standard of providing 

treatment to the “maximum extent practical” through the implementation of best management 

practices (BMPs). 

This approach is consistent with federal regulations (40 CFR § 130.2[I]), which state that TMDLs 

can be expressed in terms of mass per time (e.g., pounds per day), toxicity, or other 

appropriate measure. The TMDLs for the Southern Chain of Lakes are expressed in terms of 

kg/year, kg/day and percent reduction, and represent the long-term average annual TP load the 

lakes can assimilate to maintain the TSI threshold of 60 (Tables 6.1a and 6.1b). The TMDLs to 

be implemented are those expressed on a mass per year basis, and the expression of the 

TMDL on a mass per day basis is for information purposes only. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

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Table 6.1a. TMDL Components by Year for Total 

Phosphorus in the Southern Chain of Lakes 

WLA 

Lake WBID Wastewater 

(kg/year) 

NPDES 

Stormwatera

(% 

reduction) 

LA 

(kg/year) 

MOS 

(kg/year) 

TMDL 

(kg/year) 

% 

Reduction 

Cannon 1521H N/A 54 129 14 143 54 

Howard 1521F N/A 62.5 126 17 143 62.5 

Idylwild 1521J N/A 43 59 5 64 43 

Jessie 1521K N/A 50 127 13 140 50 

Lulu 1521 N/A 55 75 9 84 55 

May 1521E N/A 57.5 79 9 88 57.5 

Mirror 1521G N/A 27.5 51 4 55 27.5 

Shipp 1521D N/A 65 84 13 97 65 a

 The NPDES stormwater WLA is established based on the same percent reduction used for the LA. 

N/A – Not applicable 

Table 6.1b. TMDL Components by Day for Total Phosphorus 

in the Southern Chain of Lakes 

WLA 

Lake WBID Wastewater 

(kg/day) 

NPDES 

Stormwatera

(% 

reduction) 

LA 

(kg/day) 

MOS 

(kg/day) 

TMDL 

(kg/day) 

% 

Reduction 

Cannon 1521H N/A 54 0.35 0.04 0.39 54 

Howard 1521F N/A 62.5 0.35 0.05 0.39 62.5 

Idylwild 1521J N/A 43 0.16 0.01 0.18 43 

Jessie 1521K N/A 50 0.35 0.04 0.38 50 

Lulu 1521 N/A 55 0.21 0.02 0.23 55 

May 1521E N/A 57.5 0.22 0.02 0.24 57.5 

Mirror 1521G N/A 27.5 0.14 0.01 0.15 27.5 

Shipp 1521D N/A 65 0.23 0.03 0.26 65 a

 The NPDES stormwater WLA is established based on the same percent reduction used for the LA. 

N/A – Not applicable 

6.2 Load Allocation 

The LA to each lake is the sum of the existing TP ground water load and stormwater runoff load, 

shown in Table 5.2, multiplied by the percent load reduction needed to achieve the TSI 

threshold, minus an additional 5 percent of the load to provide an explicit MOS. The LAs for the 

impaired lakes in the Southern Chain varied from 51 kg/year for Lake Mirror to 129 kg/year for 

Lake Cannon. The LA to each lake represents the allocation to all nonpoint sources, which will 

be partitioned between all parties responsible for nonpoint source loadings when the specific 

source information becomes available. It should be noted that the LAs include loading from 

stormwater discharges regulated by the Department and the SWFWMD that are not part of the 

NPDES stormwater program (see Appendix B). 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

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6.3 Wasteload Allocation 

6.3.1 NPDES Wastewater Discharges 

There are no NPDES-permitted wastewater treatment facilities that discharge to surface waters 

in the Winter Haven Chain of Lakes watershed. Thus, the WLA for wastewater facilities is not 

applicable. 

6.3.2 NPDES Stormwater Discharges 

As noted in Chapter 4, loadings from stormwater discharges permitted under the NPDES 

stormwater program (i.e. MS4 areas) are placed in the WLA, rather than the LA. The WLA is 

expressed as a percent reduction and was set at the same percent reduction needed for 

nonpoint sources to meet the LA. The actual load from NPDES permitted stormwater 

discharges are included in the LA, and the LA will be portioned between all parties responsible 

for nonpoint source loadings when the specific source information becomes available. It should 

be noted that any MS4 permittee is only responsible for reducing the loads associated with 

stormwater outfalls that it owns or otherwise has responsible control over, and it is not 

responsible for reducing other nonpoint source loads in its jurisdiction. 

6.4 Margin of Safety 

TMDLs must address uncertainty issues by incorporating an MOS into the analysis. The MOS 

is a required component of a TMDL and accounts for the uncertainty about the relationship 

between pollutant loads and the quality of the receiving waterbody (Clean Water Act, Section 

303[d][1][c]). Considerable uncertainty is usually inherent in estimating nutrient loading from 

nonpoint sources, as well as predicting water quality response. The MOS can either be 

implicitly accounted for by choosing conservative assumptions about loading or water quality 

response, or explicitly accounted for during the allocation of loadings. While the Department 

usually uses an implicit MOS based on conservative assumptions in the models used to 

determine the assimilative capacity, an explicit MOS was used because there are no defined 

conservative assumptions used in the PLRG development. Five percent of the existing load, 

estimated for the 1990-1999 period, to each lake has been reserved as the MOS. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

24 

Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN 

DEVELOPMENT AND BEYOND 

7.1 Basin Management Action Plan 

Following the adoption of these TMDLs by rule, the next step in the TMDL process is to develop 

an implementation plan for the TMDLs, referred to as the BMAP. This document will be 

developed over the next two years in cooperation with local stakeholders, who will attempt to 

reach consensus on detailed allocations and on how load reductions will be accomplished. The 

BMAP will include, among other things: 

• Appropriate load reduction allocations among the affected parties, 

• A description of the load reduction activities to be undertaken, including structural projects, 

nonstructural BMPs, and public education and outreach, 

• A description of further research, data collection, or source identification needed in order to 

achieve the TMDLs, 

• Timetables for implementation, 

• Confirmed and potential funding mechanisms, 

• Any applicable signed agreement(s), 

• Local ordinances defining actions to be taken or prohibited, 

• Any applicable local water quality standards, permits, or load limitation agreements, 

• Milestones for implementation and water quality improvement, and 

• Implementation tracking, water quality monitoring, and follow-up measures. 

An assessment of progress toward the BMAP milestones will be conducted every five years, 

and revisions to the plan will be made as appropriate, in cooperation with basin stakeholders. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

25

References 

Florida Administrative Code. Chapter 62-302, Surface water quality standards.

Florida Administrative Code. Chapter 62-303, Identification of impaired surface waters. 

Florida Department of Environmental Protection. February 1, 2001. A report to the Governor 

and the Legislature on the allocation of total maximum daily moads in Florida. Tallahassee, 

Florida: Bureau of Watershed Management. 

———. June 2004. Division of Water Resource Management, Bureau of Information Systems, 

Geographic Information Systems Section, Florida Department of Environmental Protection, 

Tallahassee, Florida. Available: http://www.dep.state.fl.us/gis/contact.htm.

Florida Department of Health Web site. 2005. Available: http://www.doh.state.fl.us/ and 

http://www.doh.state.fl.us/environment/OSTDS/statistics/ostdsstatistics.htm. 

Florida LakeWatch. Florida Watershed Restoration Act. Chapter 99-223, Laws of Florida. 

Available: http://lakewatch.ifas.ufl.edu/.

McCary, J.P., and M.A. Ross. 2005. Winter Haven Chain of Lakes PLRG study. Final Report 

to the Southwest Florida Water Management District. Tampa, Florida: University of South 

Florida, Center for Modeling Hydrologic and Aquatic Systems. 

Southwest Florida Water Management District. 1998. Winter Haven Chain of Lakes Surface 

Water Improvement and Management Plan. Brooksville, Florida. 

U.S. Environmental Protection Agency. 1999. Protocol for developing nutrient TMDLs. 

Washington, D.C.: Office of Water. EPA841-B-99-007. 

Whitmore, T.J., and M. Brenner. 1995. Historic water quality assessment of selected lakes in 

the Winter Haven Chain of Lakes. Final Report to the Southwest Florida Water 

Management District. Gainesville, Florida: University of Florida, Department of Fisheries 

and Aquatic Sciences. 
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

26 

Appendices 

Appendix A: Graphs of Chlorophyll a, Total Nitrogen, and Total Phosphorus 

Sampling Results for the Southern Chain’s Impaired Lakes 

Lake Cannon - WBID 1521H 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02

Date

Chlorophyll a (ug/L)

21FLKWATPOL-CANNON-1 21FLKWATPOL-CANNON-2 21FLKWATPOL-CANNON-3 21FLPOLKCANNON1

21FLPOLKCANNON1-CA 21FLPOLKCANNON1-CC 21FLPOLKCANNON2 21FLPOLKCANNON3

21FLPOLKCANNON4 21FLPOLKCANNON5 21FLSWFDCANNON 21FLSWFDSTA0521

Lake Cannon - WBID 1521H 

Total Nitrogen Sample Results

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Date

Total Nitrogen (mg/L)

21FLKWATPOL-CANNON-1 21FLKWATPOL-CANNON-2 21FLKWATPOL-CANNON-3 21FLPOLKCANNON1

21FLPOLKCANNON1-CA 21FLPOLKCANNON1-CC 21FLPOLKCANNON2 21FLPOLKCANNON3

21FLPOLKCANNON4 21FLPOLKCANNON5 21FLSWFDCANNON
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

27

Lake Cannon - WBID 1521H 

Total Phosphorus Sample Results

0.00

0.05

0.10

0.15

0.20

0.25

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Date

Total Phosphorus (mg/L)

21FLKWATPOL-CANNON-1 21FLKWATPOL-CANNON-2 21FLPOLKCANNON1 21FLPOLKCANNON1-CA

21FLPOLKCANNON1-CC 21FLPOLKCANNON2 21FLPOLKCANNON3 21FLPOLKCANNON4

21FLPOLKCANNON5 21FLSWFDCANNON 21FLSWFDSTA0521 21FLKWATPOL-CANNON-3

Lake Howard - WBID 1521F 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02

Date

Chlorophyll a (ug/L)

21FLKWATPOL-HOWARD-1 21FLKWATPOL-HOWARD-2 21FLKWATPOL-HOWARD-3 21FLPOLKHOWARD1

21FLPOLKHOWARD1-CC 21FLSWFDHOWARD 21FLSWFDSTA0127
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

28 

Lake Howard - WBID 1521F 

Total Nitrogen Sample Results

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Nitrogen (mg/L)

21FLKWATPOL-HOWARD-1 21FLKWATPOL-HOWARD-2 21FLKWATPOL-HOWARD-3

21FLPOLKHOWARD1 21FLPOLKHOWARD1-CC 21FLSWFDHOWARD

Lake Howard - WBID 1521F 

Total Phosphorus Sample Results

0.00

0.05

0.10

0.15

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Phosphorus (mg/L)

112WRD 02294036 21FLKWATPOL-HOWARD-1 21FLKWATPOL-HOWARD-2 21FLKWATPOL-HOWARD-3

21FLPOLKHOWARD1 21FLPOLKHOWARD1-CC 21FLSWFDSTA0127 21FLSWFDHOWARD
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

29

Lake Idylwild - WBID 1521J 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05

Date

Chlorophyll a (ug/L)

21FLKWATPOL-IDYLWILD-1 21FLKWATPOL-IDYLWILD-2 21FLKWATPOL-IDYLWILD-3 21FLPOLKIDYLWILD1

21FLPOLKIDYLWILD1-CC 21FLSWFDSTA0428 21FLSWFDIDYLWILD 21FLPOLKIDYLWILD1-CA

Lake Idylwild - WBID 1521J 

Total Nitrogen Sample Results

0

0.5

1

1.5

2

2.5

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05

Date

Total Nitrogen (mg/L)

21FLPOLKIDYLWILD1 21FLPOLKIDYLWILD1-CC 21FLSWFDSTA0428 21FLKWATPOL-IDYLWILD-1

21FLKWATPOL-IDYLWILD-2 21FLKWATPOL-IDYLWILD-3 21FLSWFDIDYLWILD 21FLPOLKIDYLWILD1-CA
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

30 

Lake Idylwild - WBID 1521J

Total Phosphorus Sample Results

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05

Date

Total Phosphorus (mg/L)

21FLPOLKIDYLWILD1 21FLPOLKIDYLWILD1-CC 21FLSWFDSTA0428 21FLKWATPOL-IDYLWILD-1

21FLKWATPOL-IDYLWILD-2 21FLKWATPOL-IDYLWILD-3 21FLPOLKIDYLWILD1-CA 21FLSWFDIDYLWILD

Lake Jessie - WBID 1521K 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

90

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02

Date

Chlorophyll a (ug/L)

21FLKWATPOL-JESSIE-1 21FLKWATPOL-JESSIE-2 21FLKWATPOL-JESSIE-3 21FLPOLKJESSIE1

21FLSWFDJESSIE 21FLPOLKJESSIE1-CC 21FLSWFDSTA0288
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

31

Lake Jessie - WBID 1521K 

Total Nitrogen Sample Results

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Nitrogen (mg/L) 21FLKWATPOL-JESSIE-1 21FLKWATPOL-JESSIE-2 21FLKWATPOL-JESSIE-3 21FLPOLKJESSIE1 21FLPOLKJESSIE1-CC 21FLSWFDJESSIE

Lake Jessie - WBID 1521K 

Total Phosphorus Sample Results

0.00

0.05

0.10

0.15

0.20

0.25

0.30

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Phosphorus (mg/L)

21FLKWATPOL-JESSIE-1 21FLKWATPOL-JESSIE-2 21FLKWATPOL-JESSIE-3 21FLPOLKJESSIE1

21FLPOLKJESSIE1-CC 21FLSWFDJESSIE 21FLSWFDSTA0288
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

32 

Lake Lulu - WBID 1521 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Chlorophyll a (ug/L)

21FLKWATPOL-LULU-1 21FLKWATPOL-LULU-2 21FLKWATPOL-LULU-3 21FLPOLKLULU1

21FLPOLKLULU1-CC 21FLSWFDLULU 21FLSWFDSTA0351

Lake Lulu - WBID 1521 

Total Nitrogen Sample Results

0

1

2

3

4

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Nitrogen (mg/L)

21FLKWATPOL-LULU-1 21FLKWATPOL-LULU-2 21FLKWATPOL-LULU-3 21FLPOLKLULU1

21FLPOLKLULU1-CC 21FLSWFDLULU 21FLSWFDSTA0351
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

33

Lake Lulu - WBID 1521 

Total Phosphorus Sample Results

0

0.02

0.04

0.06

0.08

0.1

0.12

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Phosphorus (mg/L)

21FLKWATPOL-LULU-1 21FLKWATPOL-LULU-2 21FLKWATPOL-LULU-3 21FLPOLKLULU1

21FLPOLKLULU1-CC 21FLSWFDLULU 21FLSWFDSTA0351

Lake May - WBID 1521E 

Chlorophyll a Sample Results

0

10

20

30

40

50

60

70

80

90

100

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02

Date

Chlorophyll a (ug/L)

21FLKWATPOL-MAY-1 21FLKWATPOL-MAY-2 21FLKWATPOL-MAY-3 21FLPOLKMAY1

21FLPOLKMAY1-CC 21FLSWFDMAY 21FLSWFDSTA0336
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

34 

Lake May - WBID 1521E 

Total Nitrogen Sample Results

0

1

2

3

4

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Nitrogen (mg/L)

21FLKWATPOL-MAY-1 21FLKWATPOL-MAY-2 21FLKWATPOL-MAY-3 21FLPOLKMAY1

21FLPOLKMAY1-CC 21FLSWFDMAY 21FLSWFDSTA0336

Lake May - WBID 1521E 

Total Phosphorus Sample Results

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Phosphorus (mg/L)

21FLKWATPOL-MAY-1 21FLKWATPOL-MAY-2 21FLKWATPOL-MAY-3 21FLPOLKMAY1

21FLPOLKMAY1-CC 21FLSWFDMAY 21FLSWFDSTA0336
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

35

Lake Mirror - WBID 1521G 

Chlorophyll a Sample Results

0

20

40

60

80

100

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Chlorophyll a (ug/L)

21FLKWATPOL-M IRROR-1 21FLKWATPOL-M IRROR-2 21FLKWATPOL-M IRROR-3 21FLPOLKM IRROR1

21FLPOLKM IRROR1-CC 21FLTPA 28021688144296

Lake Mirror - WBID 1521G 

Total Nitrogen Sample Results

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Nitrogen (mg/L)

21FLKWATPOL-M IRROR-1 21FLKWATPOL-M IRROR-2 21FLKWATPOL-M IRROR-3 21FLPOLKM IRROR1 21FLPOLKM IRROR1-CC
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

36 

Lake Mirror - WBID 1521G 

Total Phosphorus Sample Results

0.00

0.05

0.10

0.15

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03

Date

Total Phosphorus (mg/L)

21FLKWATPOL-M IRROR-1 21FLKWATPOL-M IRROR-2 21FLKWATPOL-M IRROR-3 21FLPOLKM IRROR1

21FLPOLKM IRROR1-CC 21FLTPA 28021688144296

Lake Shipp - WBID 1521D 

 Chlorophyll a Sample Results

0

20

40

60

80

100

120

140

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Date

Chlorophyll a (ug/L)

21FLKWATPOL-SHIPP-1 21FLKWATPOL-SHIPP-2 21FLKWATPOL-SHIPP-3 21FLPOLKSHIPP1

21FLPOLKSHIPP1-CC 21FLSWFDSHIPP 21FLSWFDSTA0392 21FLTPA 25020355
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

37

Lake Shipp - WBID 1521D 

 Total Nitrogen Sample Results

0

1

2

3

4

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Date

Total Nitrogen (mg/L)

21FLKWATPOL-SHIPP-1 21FLKWATPOL-SHIPP-2 21FLKWATPOL-SHIPP-3 21FLPOLKSHIPP1

21FLPOLKSHIPP1-CC 21FLSWFDSHIPP 21FLSWFDSTA0392 21FLTPA 25020355

Lake Shipp - WBID 1521D

Total Phosphorus Sample Results

0

0.02

0.04

0.06

0.08

0.1

0.12

Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Date

Total Phosphorus (mg/L)

21FLKWATPOL-SHIPP-1 21FLKWATPOL-SHIPP-2 21FLKWATPOL-SHIPP-3 21FLPOLKSHIPP1

21FLPOLKSHIPP1-CC 21FLSWFDSHIPP 21FLSWFDSTA0392 21FLTPA 25020355
TMDL Report: Sarasota Bay–Peace–Myakka Basins, Winter Haven Southern Chain of Lakes; WBIDs 1521, 1521D, 

E, F, G, H, J, K; Nutrients

Florida Department of Environmental Protection 

38 

Appendix B: Background Information on Federal and State 

Stormwater Programs 

In 1982, Florida became the first state in the country to implement statewide regulations to 

address the issue of nonpoint source pollution by requiring new development and 

redevelopment to treat stormwater before it is discharged. The Stormwater Rule, as authorized 

in Chapter 403, F.S., was established as a technology-based program that relies on the 

implementation of BMPs that are designed to achieve a specific level of treatment (i.e., 

performance standards) as set forth in Rule 62-40, F.A.C. 

The rule requires the state’s water management districts (WMDs) to establish stormwater 

PLRGs and adopt them as part of a SWIM plan, other watershed plan, or rule. These PLRGs 

are a major component of the load allocation part of a TMDL. To date, stormwater PLRGs have 

been established for Tampa Bay, Lake Thonotosassa, the Winter Haven Chain of Lakes, the 

Everglades, Lake Okeechobee, and Lake Apopka. 

In 1987, the U.S. Congress established Section 402(p) as part of the federal Clean Water Act 

Reauthorization. This section of the law amended the scope of the federal NPDES stormwater 

permitting program to designate certain stormwater discharges as “point sources” of pollution. 

These stormwater discharges include certain discharges that are associated with industrial 

activities designated by specific standard industrial classification (SIC) codes, construction sites 

disturbing 5 or more acres of land, and master drainage systems of local governments with a 

population above 100,000, which are better known as MS4s. However, because the master 

drainage systems of most local governments in Florida are interconnected, the EPA has 

implemented Phase I of the MS4 permitting program on a countywide basis, which brings in all 

cities (incorporated areas), Chapter 298 urban water control districts, and the FDOT throughout 

the 15 counties meeting the population criteria. The Department received authorization to 

implement the NPDES stormwater program in 2000. 

An important difference between the NPDES program and other state stormwater permitting 

programs is that the former covers both new and existing discharges, while the state program 

focuses on new discharges. Additionally, Phase II of the NPDES Program, implemented in 

2003, expands the need for these permits to construction sites between 1 and 5 acres, and to 

local governments with as few as 1,000 people. - While these urban stormwater discharges are 

now technically referred to as “point sources” for the purpose of regulation, they are still diffuse 

sources of pollution that cannot be easily collected and treated by a central treatment facility as 

are other point sources of pollution, such as domestic and industrial wastewater discharges. 

The Department recently accepted delegation from the EPA for the stormwater part of the 

NPDES Program. It should be noted that all MS4 permits issued in Florida include a reopener 

clause that allows permit revisions to implement TMDLs when the implementation plan is 

formally adopted. 
Florida Department of Environmental Protection 

Division of Water Resource Management 

Bureau of Watershed Management 

2600 Blair Stone Road, Mail Station 3565 

Tallahassee, Florida 32399-2400 

(850) 245-8561 

www2.dep.state.fl.us/water/