Water Budgets, Water Quality, and Analysis

of Nutrient Loading of the Winter Park Chain 

of Lakes, Central Florida, 1989-92

By G.G. Phelps and E.R. German

With a section on Littoral Vegetation

By Brian Beckage and W. Scott Gain

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 95-4108

Prepared in cooperation with the

City of Winter Park, Florida, and

St. Johns River Water Management District

Tallahassee, Florida

1995
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Gordon P. Eaton, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only

and does not imply endorsement by the U.S. Geological Survey.

For additional information write to: Copies of this report can be 

purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey Earth Science Information Center

Suite 3015 Open-File Reports Section

227 North Bronough Street P.O. Box 25286, MS 517

Tallahassee, Florida 32301 Denver, CO 80225-0425
Contents III

CONTENTS

Abstract.................................................................................................................................................................................. 1

Introduction ........................................................................................................................................................................... 2

Purpose and Scope....................................................................................................................................................... 2

Previous Investigations................................................................................................................................................ 4

Description of the Study Area ..................................................................................................................................... 4

Methods of Investigation ............................................................................................................................................. 5

Acknowledgments ....................................................................................................................................................... 5

Lake Characteristics .............................................................................................................................................................. 5

Bathymetry .................................................................................................................................................................. 6

Bottom Sediments........................................................................................................................................................ 8

Summary of Littoral Vegetation .................................................................................................................................. 8

Water Budget ......................................................................................................................................................................... 10

Input............................................................................................................................................................................. 11

Rainfall .............................................................................................................................................................. 11

Surface Inflow ................................................................................................................................................... 14

Stormflow .......................................................................................................................................................... 14

Ground-Water Inflow......................................................................................................................................... 15

Output .......................................................................................................................................................................... 18

Lake Evaporation............................................................................................................................................... 18

Surface Outflow................................................................................................................................................. 20

Ground-Water Outflow...................................................................................................................................... 21

Budget Summary ......................................................................................................................................................... 22

Water Quality......................................................................................................................................................................... 22

Precipitation................................................................................................................................................................. 23

Surface Inflow and Lakes ............................................................................................................................................ 23

Field Measurements........................................................................................................................................... 29

Chemical and Biological Characteristics........................................................................................................... 32

Time Trends............................................................................................................................................. 33

Correlation Analysis ................................................................................................................................ 39

Stormwater................................................................................................................................................................... 44

Method of Sampling .......................................................................................................................................... 44

Chemical Characteristics ................................................................................................................................... 44

Ground Water............................................................................................................................................................... 48

Analysis of Nutrient Loading ................................................................................................................................................ 54

Constituent Budgets..................................................................................................................................................... 54

Modified Dillon-Rigler Model .................................................................................................................................... 57

Potential Effects of Stormwater Treatment ................................................................................................................. 58

Summary and Conclusions .................................................................................................................................................... 63

Selected References............................................................................................................................................................... 64

Littoral Vegetation by Brian Beckage and W. Scott Gain ..................................................................................................... 67

Appendixes ............................................................................................................................................................................ 81

PLATES

[Plates are in pocket]

Maps showing bathymetry and littoral vegetation of lakes in March 1992:

1. Lake Maitland

2. Lake Virginia

3. Lake Osceola

4. Lake Mizell
IV Contents

FIGURES

1. Map showing the Winter Park chain of lakes drainage basin................................................................................ 3

2. Color-fathometer sections from Lake Maitland, showing possible sinkholes....................................................... 7

3. Map showing bottom-sediment sampling sites and location of stormwater drains............................................... 9

4. Graph showing Lake Maitland bottom-sediment size distribution based on sieve and hydrometer analysis, 

October 1991 ......................................................................................................................................................... 10

5. Graph showing Lake Virginia bottom-sediment size distribution based on sieve and hydrometer analysis, 

October 1991 ......................................................................................................................................................... 11

6. Map showing surface water data-collection sites .................................................................................................. 13

7. Hydrograph showing monthly rainfall at Winter Park Library and water level in Lake Virginia, 

water years 1990-92............................................................................................................................................... 15

8. Hydrograph showing cumulative rainfall and change in stage of Lake Virginia, April 11-12, 1992.................... 16

9. Hydrographs showing daily discharge from Lake Sue, Lake Minnehaha, Park Lake, and Lake Maitland, 

October 1, 1989-September 30, 1992.................................................................................................................... 17

10. Generalized section showing relation of water table to potentiometric surface of the Upper Floridan 

aquifer and components of ground-water flow...................................................................................................... 18

11. Map showing surficial aquifer data-collection sites and reported septic tank locations ....................................... 19

12. Sketch showing mean flow-budget components ................................................................................................... 22

13-16. Graphs showing:

13. Median specific conductance of the Winter Park lakes and stage of Lake Virginia, 1989-92.................... 29

14. Median Secchi disk depth for the Winter Park lakes and stage of Lake Virginia, 1989-92........................ 30

15. Median dissolved oxygen concentrations for the Winter Park lakes and stage of Lake Virginia, 

1989-92 ....................................................................................................................................................... 31

16. Temperature, Secchi disk depth, and dissolved oxygen and chlorophyll-a concentrations for 

Lakes Maitland and Mizell, 1989-92 .......................................................................................................... 32

17. Diagrams showing range of medians of selected water-quality constituents for the Winter Park lakes............... 34

18-20. Graphs showing:

18. Median total phosphorus and total Kjeldahl nitrogen concentrations for the Winter Park lakes 

and stage of Lake Virginia, 1989-92 ........................................................................................................... 35

19. Median chlorophyll-a concentrations for the Winter Park lakes and stage of Lake Virginia, 1989-92...... 38

20. Selected water-quality constituents for:

a. Lake Maitland, 1967-92 ......................................................................................................................... 40

b. Lake Virginia, 1967-92 .......................................................................................................................... 41

c. Lake Osceola, 1980-92........................................................................................................................... 42

d. Lake Mizell, 1980-92 ............................................................................................................................. 43

21. Plot showing total nitrogen and phosphorus concentrations in unfiltered stormwater at two sites near 

Lake Osceola ......................................................................................................................................................... 45

22-25. Diagrams showing major ion concentrations in water from the surficial aquifer near:

22. Lake Maitland ............................................................................................................................................. 50

23. Lake Virginia .............................................................................................................................................. 51

24. Lake Osceola............................................................................................................................................... 52

25. Lake Mizell ................................................................................................................................................. 53

26. Bar graph showing total nitrogen, phosphorus, and dissolved chloride loads to the Winter Park lakes, 

1990-92.................................................................................................................................................................. 56

27-29. Graphs showing:

27. Nitrogen and phosphorus retention coefficients in Florida lakes................................................................ 59

28. Simulated steady-state nitrogen and phosphorus concentrations as a function of percent removal 

in stormwater inflow ................................................................................................................................... 61

29. Sensitivity of simulated lake concentrations of total nitrogen and total phosphorus to changes in 

quantities of ground-water inflow and outflow, stream inflow and outflow, and stormwater inflow......... 62
Contents V

TABLES

1. Physical characteristics of the Winter Park chain of lakes ..................................................................................... 6

2. Chemical analysis of bottom sediments from Lakes Virginia and Maitland.......................................................... 12

3. Surface-water data-collection sites in the Winter Park area ................................................................................... 14

4. Surficial aquifer sampling sites and head difference between lakes and the surficial aquifer ............................... 20

5. Estimated flow budgets for the Winter Park chain of lakes, water years 1990-92................................................. 22

6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92 ......................... 24

7. Water-quality variations with sampling depth in the Winter Park chain of lakes, April 1, 1992 ........................... 36

 8. Water-quality variations with sampling depth in the Winter Park chain of lakes, June 11, 1992 .......................... 37

9. Water-quality characteristics of stormwater at site 9 (Webster Drive) near Lake Osceola .................................... 46

10. Water-quality characteristics of stormwater at site 11 (Elizabeth Drive) near Lake Osceola ................................ 47

11. Surficial ground-water quality in the vicinity of the Winter Park chain of lakes................................................... 49

12. Estimated chloride and nutrient budgets for the Winter Park chain of lakes, water years 1990-1992................... 55

CONVERSION FACTORS, VERTICAL DATUM, ABBREVIATIONS, AND ACRONYMS

Sea level: In this report "sea level" refers to the National Geodetic Vertical Datum of 1929--a geodetic datum derived from a general 

adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929.

Equations for temperature conversion between degrees Celsius (°C) and degrees Fahrenheit (°F):

 °C = 5/9 (°F - 32)

 °F = 9/5 (°C) + 32 

Altitude, as used in this report, refers to distance above or below sea level.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25 °C).

Concentrations of chemical constituents in sediments are given either in milligrams per kilogram (mg/kg), grams per kilogram (g/kg), or 

micrograms per kilogram (μg/g).

Mass-to-volume ratios of stormwater debris are given in lb/gal. 

Areal loading ratios are given in grams per square meter per year (g/m2

/yr)

Multiply By To obtain 

Length 

inch (in.) 2.54 centimeter

foot (ft) 0.3048 meter 

mile (mi) 1.609 kilometer 

Area

acre 4,047 square meter

square foot (ft2) 0.0929 square meter

square mile (mi2

) 2.590 square kilometer 

Volume

gallon (gal) 3.785 liter 

gallon (gal) 0.003785 cubic meter 

cubic foot (ft3

) 0.028317 cubic meter 

Flow

foot per day (ft/d) 0.3048 meter per day 

cubic foot per second (ft3

/s) 0.02832 cubic meter per second 

inch per day (in/d) 2.54 centimeter per day

inch per month (in/mo) 2.54 centimeter per month 

inch per year (in/yr) 2.54 centimeter per year 

Mass

pounds (lb) 0.454 kilograms

tons per year (tons/yr) 0.9072 metric ton per year
VI Contents

 

ADDITIONAL ABBREVIATIONS

ft/ft feet/foot min minute

fw filtered water mo month

D discharge computed N nitrogen

g gram NTU Nephelometric turbidity units

g/kg grams per killogram P phosphorus

kHz kilohertz Pt-Co Units Platinum-Cobalt units

L liter QW bimonthly water-quality samples

μg/g micrograms per gram R rainfall

μg/L micrograms per liter rw raw water

μm micrometer S continuous stage

μS/cm microsiemens per centimeter at SD discharge for selected storms

25 degrees Celsius SS stage for selected storms

mg/g milligrams per gram ST stormwater-inflow samples

mg/kg milligrams per killogram SU Standard Unit

mg/L milligrams per liter sw screened water

mL milliliter Wh whole water

mm millimeter yr year

ACRONYMS

CF color fathometer

NOAA National Oceanic and Atmospheric Administration

SIN:SRP ratios of total-soluble-inorganic-nitrogen to

total-soluble-reactive-phosphate

TKN total Kjeldahl nitrogen

TOC total organic carbon

TSI tropic-state index

USEPA U.S. Environmental Protection Agency

USGS U.S. Geological Survey
Abstract 1

Water Budgets, Water Quality, and Analysis

of Nutrient Loading of the Winter Park

Chain of Lakes, Central Florida, 1989-92

By G.G. Phelps and E.R. German

Abstract

The Winter Park chain of lakes (Lakes 

Maitland, Virginia, Osceola, and Mizell) has a 

combined area of about 900 acres, an immediate 

drainage area of about 3,100 acres, and mean 

depths ranging from 11 to 15 feet. The lakes are 

an important recreational resource for the 

surrounding communities, but there is concern 

about the possible effects of stormwater runoff 

and seepage of nutrient-enriched ground water on 

the quality of water in the lakes.

The lakes receive water from several 

sources: rainfall on lake surfaces, inflow from 

other surface-water bodies, stormflow that enters 

the lakes through storm drains or by direct runoff 

from land adjacent to the lakes, and ground-water 

seepage. Water leaves the lakes by evaporation, 

surface outflow, and ground-water outflow. Of the 

three, only surface outflow can be measured 

directly. Rainfall, surface inflow and outflow, and 

lake-stage data were collected from October 1, 

1989, to September 30, 1992. Stormflow, 

evaporation and ground-water inflow and outflow 

were estimated for the 3 years of the study. 

Ground-water outflow was calculated by 

evaluating the rate of lake-stage decline during 

dry periods. Estimated ground-water outflow was 

compared to downward leakage rates estimated 

by ground-water flow models. Lateral groundwater inflow from surficial sediments was 

calculated as the residual of the flow budget.

Flow budgets were calculated for the 

3 years of the study. In water year 1992 (a year 

with about average rainfall), inflow consisted of 

rainfall, 48 inches; stormflow, 15 inches; surface 

inflow, 67 inches; and ground water, 40 inches. 

The calculated outflows were evaporation, 

47 inches; surface outflow, 90 inches; and ground 

water, 33 inches.

Water-quality data also were used to 

calculate nutrient budgets for the lakes. 

Bimonthly water samples were collected from the 

lakes and at surface inflow and outflow sites, and 

were analyzed for physical characteristics, 

dissolved oxygen, pH, specific conductance, 

major ions, the nutrients nitrogen and phosphorus, 

and chlorophyll (collected at lake sites only). 

Specific conductance ranged from about 190 to 

230 microsiemens per centimeter at 25 degrees 

Celsius in Lakes Maitland, Virginia and Osceola 

and from about 226 to 260 microsiemens per 

centimeter at 25 degrees Celsius in Lake Mizell. 

The median concentrations of total ammoniaplus-organic nitrogen in all the lakes ranged from 

0.79 to 0.99 milligrams per liter. Median total 

phosphorus concentrations ranged from less than 

0.02 to 0.20 milligrams per liter. Stormwater 

samples were collected for 17 storms at one 

storm-drain site and 16 storms at another stormdrain site on Lake Osceola. Median total nitrogen 

concentrations at the sites were 2.23 and 

3.06 milligrams per liter and median total 

phosphorus concentrations were 0.34 and 

0.40 milligrams per liter.

The water quality in the Winter Park lakes 

generally is fair to good, based on a trophic-state 

index used by the Florida Department of 

Environmental Protection for assessing the tropic 

state of Florida lakes. This index was determined 
2 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

from median total nitrogen, total phosphorus, and 

chlorophyll-a concentrations, and median Secchidisk transparency for all lakes for the period 

September 1989 to June 1992.

Based on a one-time sampling of 20 sites 

around the lakes, surficial ground-water quality is 

highly variable. Nutrient concentrations were 

highly variable and could not be correlated to the 

proximity of septic tanks. Fertilizer probably is the 

primary source of nutrients in the surficial ground 

water.

Nutrient budgets were calculated for the 

lakes for the 3 years of the study. The most variable 

source of nutrient loading to the lakes is 

stormwater. Nutrient-loading modeling indicates 

that reduction of nutrients in stormflow probably 

would improve lake-water quality. However, even 

with complete removal of nitrogen and phosphorus 

from stormwater, the lakes might still be 

mesotrophic with respect to both nutrients during 

periods of below average rainfall because of the 

input from the other sources of inflow to the lakes.

Littoral vegetation in the lakes was surveyed 

in March 1992. The length of shoreline containing 

vegetation was 44 percent in Lake Maitland, 

62 percent in Lake Virginia, 46 percent in Lake 

Osceola, and 76 percent in Lake Mizell. The types 

of vegetation present generally were similar for all 

four lakes.

INTRODUCTION

The Winter Park chain of lakes, located in the cities of Winter Park and Maitland, Florida, consists of 

Lakes Virginia, Mizell, Osceola, and Maitland. The 

lakes are part of a 21-lake system that begins with 

Spring Lake in Orlando and ends with the outflow from 

Lake Maitland to Howell Creek. The system has a total 

drainage area of about 17 mi2

 (fig. 1). The four lakes of 

the Winter Park chain are connected by navigable 

canals.

The area around the lakes is highly urbanized. 

Much of the land use in the area is residential. Commercial areas of downtown Winter Park and Maitland and 

the campus of Rollins College occupy part of the drainage area. Orange groves are cultivated in a small area 

along the north side of Lake Mizell and in the area 

between Lakes Osceola and Mizell. The 1994 combined 

population of the cities of Winter Park and Maitland 

was about 33,500 residents.

The lakes are an important recreational resource 

that provide fishing, boating, and swimming, as well as 

a scenic setting for lakeside estates and the surrounding 

communities. Because of the value of the lakes as an 

aesthetic and recreational resource, there is concern 

about the possible impact of development in the basin 

on lake-water quality. Quality of water in the lakes can 

be affected by stormwater from the surrounding area 

and seepage of ground water enriched by nutrients from 

fertilizer, septic tanks, or leaking sewer lines. Other 

sources of water entering the lakes include precipitation 

and surface flow from upstream lakes. Occasional algal 

blooms and high bacteria counts in Lake Virginia, 

resulting in long-term closing of the swimming beach, 

have increased the concerns of water managers and residents about lake-water quality. Knowledge of the relative contribution from various sources of the nutrient 

load to the lakes is needed so that a management plan 

for maintaining or improving lake-water quality can be 

designed. The U.S. Geological Survey (USGS) began a 

4-year study of the Winter Park chain of lakes in cooperation with the city of Winter Park and the St. Johns 

River Water Management District in order to quantify 

the hydrologic budgets for the lakes, to assess the quality of lake and inflow water, and, ultimately, to determine the principal sources of nutrient (nitrogen and 

phosphorus) loading to the lakes.

Purpose and Scope

This report summarizes the results of the 

4-year study of the Winter Park chains of lakes. It 

includes the estimated 1990-92 water budgets for the 

lakes. Elements of the budgets include surface inflow 

from the basin upstream, rainfall directly onto lake 

surfaces, stormwater inflow from the immediate 

drainage area and from storm drains, ground-water 

inflow, evaporation, surface outflow and groundwater outflow. Water quality and seasonal variation 

of water quality in the lakes and in surface inflow and 

outflow are also described. Data presented include 

concentrations of major ions, nutrients, chlorophyll-a

and -b, pH, dissolved oxygen, and measurements of 

transparency. Also summarized are nutrient concentrations in stormwater inflow based on sampling 

17 storms at 1 site and 16 storms at another site 
Introduction 3

Figure 1. The Winter Park chain of lakes drainage basin.

Orange

County

Lake

Lucien Lake

Charity

Lake

Hope

Lake

of the

Lake Woods

Faith

Howell

Lake

Adair Lake

Highland

Lake

Ivanhoe

Lake

Killarney

Lake

Concord

Lake

Berry

WINTER PARK

MAITLAND

ORLANDO

SEMINOLE CO.

ORANGE CO.

Polk County

Seminole County

DRAINAGE BASIN

BOUNDARY

Lisbon,

Lake County

Creek

Spring

Lake

28 ̊ 40’

81 ̊ 25’ 81 ̊ 20’

28 ̊ 35’

Lake

Maitland

Lake

Osceola

Rollins

College Lake

Mizell

Lake

Virginia

Lake

Minnehaha

Lake Howell

Lake

Sue

436

50

92

17

I-4

STUDY AREA

0 1

0 1 2 KILOMETERS

2 MILES
4 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

during 1989-92, and the relative proportions of nutrients in the dissolved, fine-particulate matter, and leafsized debris fractions of the total stormwater load. A 

preliminary appraisal of the quality of the surficial 

ground water surrounding the lakes, based on one-time 

samples collected at 20 sites, is also presented. Flow 

and water-quality data have been combined to provide 

estimates of a nutrient budget for the chain of lakes 

and an analysis of nutrient loading using a steady-state 

input-output model. The report also includes a catalog 

of emergent littoral vegetation existing in March 1992, 

a bathymetric survey of the lakes, and a tabulation of 

chemical and physical characteristics of sediment collected along 1 transect each in Lakes Virginia and 

Maitland.

Previous Investigations

The general hydrology of the Winter Park chain 

of lakes area is included in the description of the water 

resources of Orange County, Florida, by Lichtler, 

Anderson and Joyner (1968). The water quality of 

nearby Lakes Faith, Hope, Charity, and Lucien was 

studied by German (1983). Research by the Biology 

Department of Rollins College (1979) included studies 

of plankton, fish, and selected plant species in the 

Winter Park chain of lakes, as well as analysis of lakebottom cores and a preliminary model of lake water 

turnover. Another report prepared at Rollins College 

(Small, Richard, and Gregory, 1988) summarized 

water-quality data and biologic information collected 

in the lakes from 1984-88. The lack of inflow and outflow data for the chain of lakes was noted during those 

studies. An evaluation of the lakes was prepared for 

the city of Winter Park by Professional Engineering 

Consultants (1987). An inventory of septic tanks 

around the lakes was prepared for the city of Winter 

Park by Glace and Radcliff, Inc. (1989) and included a 

study of the fluctuations of surficial ground-water 

levels and of some chemical constituents in water 

samples collected downgradient from the septic tanks.

Description of the Study Area

The Winter Park chain of lakes is part of a 21-

lake system that begins in Orlando and drains northeastward to Howell Creek (fig. 1). The drainage basin 

for the total lake system is about 17 mi2

, of which 

approximately 3 mi2 is water surface. The four lakes 

included in this report have a combined water-surface 

area of about 900 acres (1.4 mi2

). Lake Maitland has a 

surface area of 470 acres; Lake Virginia, 224 acres; 

Lake Osceola, 154 acres; and Lake Mizell, 66 acres. 

The immediate drainage area of the lakes is about 

3,100 acres (3.5 mi2) (Professional Engineering 

Consultants, Inc., 1987). 

The drainage area of the chain of lakes lies 

across the boundary of two topographic areas delineated by Lichtler, Anderson, and Joyner (1968, fig. 3) 

and termed the “intermediate” and the “highlands” 

areas. The north part of the study area is in the intermediate topographic area, where land-surface altitudes 

generally range from 50 to 85 ft, including swamps in 

the low-lying areas. To the south is the highlands 

region, where land-surface altitudes typically are 

greater than 105 ft. The highlands area is characterized 

by sinkhole lakes and closed depressions. Landsurface altitude around the Winter Park chain of lakes 

is about 68 ft and lake-surface altitudes are about 66 ft. 

Within a mile to the east, south, and west of the lakes, 

land-surface altitudes rise to about 85 to 100 ft; and to 

the north, about 75 to 85 ft.

The climate of the Winter Park Lakes area is 

humid and subtropical. The average annual temperature measured at nearby Orlando is 72.4 °F, and the 

average annual rainfall is about 48 in. (National 

Oceanic and Atmospheric Administration, 1990). 

Total annual rainfall at Orlando for 1990 was 31.68 in. 

and for 1991, 60.91 in. The annual distribution of rainfall is characterized by two distinct seasons: a summer 

rainy season (June-September), when about 50 percent 

of the total annual rainfall usually occurs, and a dry 

season (October-May). During the rainy season, 

convection thunderstorms predominate, resulting in a 

spatially non-uniform distribution of rainfall. During 

the dry season, rainfall usually is associated with cold 

fronts and is more uniformly distributed across the 

area.

The surficial sediments in the area are mostly 

sands with some organic debris and occasional layers 

of clay or clayey sand. The thickness of the surficial 

sediments ranges from about 50 to about 75 ft. Underlying the surficial sands are sediments of Miocene age. 

Some of the sediments are undifferentiated clayey 

sands and some are the Hawthorn Formation. Hawthorn sediments include clayey sand, clay, and phosphate-bearing limestone and sandstone. The clayey 

sediments of the Hawthorn Formation do not form a 

continuous confining layer, but do retard the downward seepage of water from the water table to the 
Lake Characteristics 5

underlying Upper Floridan aquifer. The Miocene sediments range in thickness from about 75 to about 95 ft. 

Underlying the Miocene sediments is the Eocene 

Ocala Limestone of the Upper Floridan aquifer. The 

top of the Ocala Limestone was identified at about 

175 ft below land surface in a well approximately 

1/2 mi west of Lake Virginia. However, the surface of 

the limestone has been modified by erosion and the 

altitude of the top of the formation varies widely. Sinkholes, caused by fluctuations in the potentiometric surface of the Upper Floridan aquifer combined with the 

gradual subsurface movement of unconsolidated sediments into solution features in the limestone, are 

actively forming in the Winter Park area.

Methods of Investigation

Because of the complexity of this multidiscipline study, detailed information about data-collection 

methods is given in respective sections of this report. 

Data-collection methods can be summarized as 

follows: 

• Surface inflow to the lakes was gaged at three 

tributaries flowing into the lakes. Outflow from 

the chain of lakes was computed from lake stage 

in Lakes Virginia and Maitland using a rating 

based on a series of field discharge measurements 

at the outflow weir on Lake Maitland. 

• Rainfall was measured using a recording tippingbucket rain gage. 

• Stormflow was estimated by analyzing lake-stage 

hydrograph rises immediately following storms 

and evaporation was calculated using nearby pan 

evaporation data.

• Ground-water outflow was calculated by analyzing lake-stage hydrograph recession during dry 

periods and ground-water inflow was calculated 

as the residual of the water-flow budget. 

• The quality of inflow and lake water was determined from bimonthly samples collected from 

October 1989 to May 1992. 

• Samples of stormwater inflow from 2 storm 

drains on Lake Osceola were collected from 

17 storms at one site and 16 storms at the other 

site and analyzed for nutrients, specific conductance, and dissolved solids. 

• The nutrient content and rate of nutrient leaching 

from leaf debris were studied using samples of 

leaves removed from screens around storm 

drains. 

• Surficial ground water was sampled using a drivepoint sampler at 20 sites during February-June 

1992. 

• Bathymetric contours of the lakes were drawn 

based on data derived from color fathometer 

surveys of the lakes made in February and March 

1992. 

• Grab samples of lake-bottom materials were 

collected in October 1991 using an Eckman 

dredge at 7 sites each in Lakes Virginia and 

Maitland. Samples were analyzed for nutrients, 

total carbon, lead, and zinc, and a grain-size 

analysis was made by sieve and hydrometer. 

• A field survey of littoral vegetation in the lakes 

was made in March 1992.

Acknowledgments

The authors gratefully acknowledge T. L. 

Turner, E. P. Simonds, M. Brizio, and S. Jacobs, all of 

the U.S. Geological Survey, for their contributions in 

this study.

LAKE CHARACTERISTICS

The biological, geological, and chemical characteristics of a lake (which affect the trophic state of 

the lake) are closely related to the age of the lake, 

climate, local geology, and lake morphology, in addition to such factors as local land use and the quality of 

inflow water. Eutrophication is the process through 

which lakes become enriched by nutrients and gradually become filled with sediments, ultimately becoming dry land. As nutrients and sediment deposits 

accumulate, vegetation growth increases and the depth 

of the lake decreases. As the lake becomes shallower, 

the eutrophication process accelerates and the lake 

eventually becomes a bog or swamp, and, finally, dry 

land. This is a natural process and is the fate of most 

lakes. However, the effects of human activity can 

greatly accelerate the eutrophication process.

Nutrient-poor lakes, termed oligotrophic, are 

characterized by high concentrations of dissolved 

oxygen at all depths and low concentrations of dissolved-chemical constituents, particularly nutrients. 

Mesotrophic lakes are characterized by increased 

concentrations of dissolved constituents and increased 

plant growth, but not so excessively that plants become 

a threat to aquatic animal habitats and a nuisance to 
6 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

human activities. Eutrophic lakes are characterized by 

high concentrations of dissolved chemicals and nutrients, large numbers of phytoplankton (small plants of 

which algae are the most commonly known variety), 

and oxygen depletion with depth (Phelps, 1982).

The lakes of the Winter Park chain are relatively 

shallow (mean depths calculated during this study range 

from about 11 to 15 ft), which can affect lake-water 

quality by providing an environment suitable for rapid 

algal and submergent plant growth. Some physical characteristics of the lakes are summarized in table 1. The 

volume for each lake was calculated by digitizing the 

areas within each depth contour. Volume data are useful 

for calculating lake budgets and hydraulic-residence 

time.

Bathymetry

Surveys of the four lakes were made in FebruaryMarch 1992 using ground-penetrating radar and a color 

fathometer. Ground-penetrating radar has been used in 

some lakes to estimate the thickness of bottom sediments or the depth to a hard, reflecting geologic unit, 

such as the top of limestone. The purpose of using 

ground-penetrating radar was to locate possible sinkholes in the lakes, but the technique was not effective 

because the radar signal was attenuated at water depths 

of about 15 to 20 ft, possibly because of the dissolved 

solids concentrations in the lake water.

Color fathometer (CF) surveys of all 4 lakes also 

were made. The CF transmits signals in the 20 to 100 

kHz frequency range. The transmitted and reflected signals are shown on a screen similar to a color computer 

monitor and also are recorded on digital audio tapes for 

later replay. The replays of data from the surveys were 

recorded on video tape.

Table 1. Physical characteristics of the Winter Park chain of lakes

[Drainage area data from Professional Engineering Consultants, 1987, table 1. Area and volume calculated at a lake stage of 66.09 ft above sea level in 

March 1992. Mean depth = volume/surface area. ft2, square foot; ft3, cubic foot; ft, foot; --, not applicable]

Lake

Drainage

area

(acres)

Surface area Volume

(ft3)

Shoreline

length

(miles)

Maximum

depth

(ft)

Mean

depth

(ft) (acres) (ft2)

Maitland 1,374 470 20.5 x 106 23.3 x 107 6.2 30 11.4

Virginia 944 224 9.8 x 106 14.8 x 107 2.9 23 15.1

Osceola 567 154 6.7 x 106 7.2 x 107 2.8 23 10.7

Mizell 258 66 2.9 x 106 3.1 x 107 1.4 21 10.7

Total 3,143 914 39.9 x 106 48.4 x 107 13.3 -- --

The CF is useful because, in addition to showing 

the depth of the lake, the signals can penetrate into lakebottom materials, and provide information about the 

density of sediments. The best results were obtained 

using a transmission frequency of 20 kHz. Reflected signals with a small amplitude (weak signals) are blue and 

generally indicate soft bottom material. As the amplitude 

of the reflected signals become larger (stronger) the 

color changes from green to yellow to red. A red signal 

indicates hard bottom or subbottom materials. CF can be 

used in water depths greater than about 5 ft.

Bathymetric maps of Lakes Maitland, Virginia, 

Osceola, and Mizell compiled using the CF data are 

shown in plates 1-4. The lakes are all relatively shallow, 

with maximum depths ranging from about 30 ft in Lake 

Maitland to 21 ft in Lake Mizell.

During most of the CF traverses, the reflected 

signals indicated good signal penetration into relatively 

soft sediments. In a few areas, lake-bottom vegetation 

prevented good signal penetration into the bottom sediments.

Three bottom features that could be sinkholes 

were noted in Lake Maitland (fig. 2, pl. 1 for site location). Feature 11-M (fig. 2) is about 140 ft across and 

the bottom depth at the site suddenly drops from about 

15 to about 25 ft. Feature 8-M is about 110 ft across 

with a depth change of about 10 ft. The bottom material 

at both 8-M and 11-M is soft. Feature 4-M, which is 

about 85 ft across, is actually two coalescing features. 

The dark CF signal (red) at the bottom of 4-M was the 

hardest subsurface material noted in the CF surveys and 

could be limestone. If limestone is present in the lake 

bottom, downward leakage through the lake bottom can 

be a significant component of the flow budget. No sinkhole-like features were noted in the other lakes. However, more detailed CF surveys would be needed to 

eliminate the possible presence of other sinkholes.
L

akeCharacteristics7Figure 2. Color-fathometer sections from Lake Maitland, 

FEATURE 4-M

0 30

0 9 18 27 MET

60 90 FEE

APPROXIMATE HORIZONTAL DISTANCE

VERTICAL EXAGGERATION X3

DEPTH BELOW WATER

SURFACE, IN FEET

0

10203040

FEATURE 8-M

0 300 9 18 27 METERS

60 90 FEET

APPROXIMATE HORIZONTAL DISTANCE

VERTICAL EXAGGERATION X2

DEPTH BELOW WATER

SURFACE, IN FEET

0

10203040

10

2030

0 30

0 9 18 27 36 METERS

60 90 120 FEET

APPROXIMATE HORIZONTAL DISTANCE

VERTICAL EXAGGERATION X3.5

FEATURE 11-M

DEPTH BELOW WATER

SURFACE, IN FEET

0

10203040
8 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Bottom Sediments

Bottom sediment samples were collected using 

an Eckman dredge along traverses in Lakes Maitland 

and Virginia and sediment sizes were determined 

using sieves and a hydrometer. The traverses are 

shown in figure 3.

Because this sampling was a reconnaissance, 

grab samples were collected with a dredge, from 

which small-sized sediments could be washed out 

during the collection process, thus causing a bias in 

favor of larger grain sizes. Therefore, no conclusions 

about sedimentation rates can be made from the data. 

A series of lake-bottom core samples could provide 

more information about sedimentation rates. 

The distributions of bottom-sediment grain sizes 

for the two traverses are shown in figures 4-5. Most of 

the sediments were fine- to medium-grained sand with 

an average grain-size diameter in the range of about 

0.1 to 1.0 mm. At site M-6, the bottom was so hard 

that the dredge was unable to collect a sample. The 

samples collected at sites M-2, V-3, and V-4 contained 

a greater proportion of finer sediments than samples 

collected at the other sites. The size distribution of 

sediments in the lakes probably is related to the combined effects of currents, wind and boat traffic.

 The lake-bottom sediment samples collected in 

Lakes Virginia and Maitland on October 2, 1991, were 

analyzed for nutrients, total carbon, lead and zinc 

(table 2). The samples containing the greatest percentage of fine sediments, M-2, V-3, and V-4 (figs. 4 and 5),

also had the highest concentrations of lead and zinc. 

This probably is because metals tend to be adsorbed on 

fine-grained sediment particles (often clay) as opposed 

to coarser, sandy sediments. The sites from which the 

samples in Lake Virginia were collected (fig. 3) show 

the influence of storm drains. The northeast side of the 

lake is relatively undeveloped and has no storm drains. 

The sediments on that side of the lake had a lower percentage of fine sediments and lower lead and zinc concentrations than sites V-3 And V-4, which are closer the 

area where storm drains are present. The fine sediments 

probably are carried into the lakes in the stormflow.

The samples with the highest percentages of fine 

sediments also had the highest concentrations of total 

carbon. This probably is because fine-grained sediments 

incorporate decaying plant material. The resuspension 

of fine-grained sediments could contribute to the concentrations of total nitrogen and phosphorus in lake 

water, especially in relatively shallow lakes and during 

dry periods, when the lake volume is smaller.

Previous investigators (Rollins College, 1979, p. 

1) were concerned that sedimentation rates in the lakes 

seemed to be high, causing rapid infilling. However, 

based on the limited bottom-sediment sampling in this 

study and on comparison of current bathymetry to past 

data, there are no indications of rapid sediment infilling of the lakes.

Summary of Littoral Vegetation

Vegetation in the littoral (near shore) part of lakes 

can be important to the lake processes that affect 

eutrophication. The growth of some plants can be useful 

because they remove nutrients (nitrogen and phosphorous) from the water. However, the excessive growth of 

“nuisance” plants, such as hydrilla, can be detrimental 

because they contribute large amounts of plant detritus 

to the lake, which can adversely affect water quality and 

habitats. Many factors, such as disturbance of the shoreline and its overstory, nutrient concentrations in the lake 

water, and erosion and sedimentation rates, interact with 

natural conditions to affect the diversity of plant species 

in a lake. The extent and character of emergent vegetation is also strongly influenced by the means and 

extremes of water levels in the lake. 

A reconnaissance survey of the emergent littoral 

vegetation in the Winter Park chain of lakes was made 

by personnel of the U.S. Geological Survey in March 

1992. Plants were identified to species, but in some 

instances only to family. Woody species were inventoried but were excluded from areal coverage estimates 

because areal coverages for woody and non-woody species cannot be readily compared. The percentages of 

shoreline containing vegetation were: Lake Maitland, 

44 percent; Lake Osceola, 46 percent; Lake Virginia, 

62 percent; and Lake Mizell, 76 percent. Generally, the 

types of vegetation in all four lakes were similar, which 

is not surprising given the proximity of and connection 

between the lakes. Lake Maitland was dominated by 

torpedo grass, followed by cattails, with bald cypress 

present in more than 50 percent of the lake sections. 

Lake Virginia was dominated by cattails, followed by 

torpedo grass, with bald cypress and water primrose 

present in about 25 percent of the sections. Lake 

Osceola was not clearly dominated by any species, but 

torpedo grass and other Panicum species were most prolific, with bald cypress in 33 percent and water primrose 

in 25 percent of the sections. Nuisance vegetation did 

not seem to be a problem in the lakes. A detailed 

description of the vegetation survey is presented at the 

end of this report.
Lake Characteristics 9

0

0 .5 1 KILOMETER

.5 1 MILE

28 ̊38 ́

81 ̊22 ́ 21 ́ 81 ̊20 ́

37 ́

36 ́

28 ̊35 ́

Park

Lake

Lake

Sybelia

Lake

Minnehaha

Howell

Lake

Sue

Lake

Berry

Horatio Ave.

Howell Branch Rd.

Park Ave.

Park Ave.

Palmer Ave.

Aloma Ave.

Winter Park

Library

Fairbanks Ave.

Rollins

College

Mead

Garden

Creek

28 ̊38 ́

81 ̊22 ́ 81 ̊20 ́

37 ́

36 ́

28 ̊35 ́

Park

Lake

Lake

Sybelia

Lake

Minnehaha

Howell

Lake

Maitland

Lake

Osceola

Lake

Mizell

Lake

Virginia

Lake

Sue

Lake

Berry

Horatio Ave.

Park Ave.

Park Ave.

Palmer Ave.

Aloma Ave.

Winter Park

Library

Fairbanks Ave.

Orange Ave.

Osceola

Ave.

Rollins

College

Creek

EXPLANATION

M-6 SEDIMENT SAMPLING

SITE

STORMWATER DRAIN

M-1

M-2

M-3

M-4

M-5

M-6

M-7

V-1

V-3

V-2

V-5

V-6

V-4

V-7

92

17

Figure 3. Bottom-sediment sampling sites and location of stormwater drains.
10 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

estimate water budgets for the chain of lakes for water 

years 1990-92. A simple water budget can be written 

as: 

Rainfall + Surface Inflow + Stormflow

+ Ground-water Inflow = Evaporation

+ Surface Outflow + Ground-water Outflow 

+ Storage Change. (1)

WATER BUDGET

Inflow to, outflow from, and volume changes in 

the lakes were measured or estimated for 3 years 

(water years October 1, 1989, to September 30, 1992) 

to calculate flow and nutrient budgets for the Winter 

Park chain of lakes. The locations of surface water 

data-collection sites are shown in figure 6 and information about the types of data collected at each site is 

listed in table 3. Rainfall was measured at the Winter 

Park Library (fig. 6). The flow data were combined to 

Figure 4. Lake Maitland bottom-sediment size distribution based on sieve and hydrometer analysis, October 1991 (site 

numbers are from fig. 3). CUMULATIVE PERCENT

PARTICLE DIAMETER, IN MILLIMETERS

0

100

10

20

30

40

50

60

70

80

90

0.001 0.01 0.1 1

M-1

SILT FINE

SAND

VERY

FINE

SAND

COARSE

SAND

MEDIUM

SAND

M-2

M-3

M-4

M-5

M-7
Water Budget 11

seepage, more difficult to measure, were estimated for 

the 3 years of the study. 

Rainfall

A tipping-bucket rain gage, installed on the roof 

of the Winter Park Library, measured rainfall near the 

lakes during the study (fig. 6). The gage was placed 

near the center of the roof to minimize the effects of 

updrafts near the sides of the building. Measured rainInput

The lakes receive water from direct precipitation, stream inflow from other lakes, stormflow 

including direct runoff from land adjacent to the lakes 

and water from storm drains, and from ground-water 

seepage. Rainfall and surface inflow were measured 

directly during the study. Stormflow and ground-water 

Figure 5. Lake Virginia bottom-sediment size distribution based on sieve and hydrometer analysis, October 1991 (site 

numbers are from fig. 3). CUMULATIVE PERCENT

PARTICLE DIAMETER, IN MILLIMETERS

0

100

10

20

30

40

50

60

70

80

90

0.001 0.01 0.1 1

SILT FINE

SAND

VERY

FINE

SAND

COARSE

SAND

MEDIUM

SAND

V-1

V-2

V-3

V-4

V-5

V-6

V-7
12 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 fall was 37.96 in. for water year 1990, 58.49 in. for 1991, and 47.50 in. for 1992. The average rainfall at the Winter Park 

the study Table 2. Chemical analysis of bottom sediments from Lakes Virginia and Maitland [Site numbers are from figure 3. mg/kg, milligrams per kilogram; g/kg, gram per kilogram; μg/g, micrograms per gram; <, less than] Site num- ber Site identification number Moisture content, dry weight (percent of total) Nitrogen, NH4 total in bottom material (mg/kg as N) Nitrogen, NH4 + organic, total in bottom material (mg/kg as N) Nitrogen, NO2+NO3 total in bottom material (mg/kg as N) Phosphorus, total in bottom material (mg/kg as P) Carbon, inorganic + organic, total in bottom material (g/kg as C) 

V-1 283505081204900 82 27 9,900 <2.0 1,600 120 V-2 283508081204500 72 62 5,400 <2.0 680 67 V-3 283510081204100 90 220 19,000 <2.0 1,800 270 V-4 283513081203700 90 200 20,000 7.0 1,500 240 V-5 283516081203300 52 17 1,700 <2.0 230 16 V-6 283518081202900 21 1.3 280 3.0 <40 1.8 V-7 283521081202500 71 17 4,700 12 42 46 M-1 283641081211100 31 25 1,100 <2.0 590 34 M-2 283648081210900 85 94 12,000 13 4,400 260 M-3 283655081210700 77 41 5,900 <2.0 1,700 69 M-4 283702081210500 43 6.6 1,400 <2.0 71 15 M-5 283708081210300 21 1.0 240 <2.0 <40 1.1 M-6 283715081210000 31 2.6 860 <2.0 79 8.1 M-7 283722081205800 84 260 6,600 <2.0 660 58 
Water Budget 13

0

0 .5 1 KILOMETER

.5 1 MILE

28 ̊38 ́

81 ̊22 ́ 21 ́ 81 ̊20 ́

37 ́

36 ́

28 ̊35 ́

Park

Lake

Lake

Sybelia

Lake

Minnehaha

Howell

Lake

Maitland

Lake

Sue

Lake

Berry

Horatio Ave.

Park Ave.

Park Ave.

Palmer Ave.

Aloma Ave.

Winter Park

Library

Fairbanks Ave.

Osceola Ave.

Rollins

College

Mead

Garden

Creek

28 ̊38 ́

81 ̊22 ́ 81 ̊20 ́

37 ́

36 ́

28 ̊35 ́

Park

Lake

Lake

Sybelia

Lake

Minnehaha

Howell

Lake

Maitland

Lake

Osceola

Lake

Mizell

Lake

Virginia

Lake

Sue

Lake

Berry

Horatio Ave.

Howell Branch Rd.

Park Ave.

Palmer Ave.

Webster Ave.

Elizabeth Dr.

Aloma Ave.

Winter Park

Library

Orange Ave.

Osce a Ave.

Rollins

College

Creek

EXPLANATION

1

18

18

SURFACE-WATER-DATA

RAINFALL-DATA COLLECTION

1

16

15

12

10

9

8

7

6

3

2

4

5

11

13

14

17

COLLECTION SITE AND

NUMBER FROM TABLE 3

SITE AND NUMBER

FROM TABLE 3

17

92

Figure 6. Surface water data-collection sites.
14 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

was 47.98 in. Average yearly rainfall at the Orlando 

International Airport (about 12 mi south of Winter 

Park) is about 48 in. Rainfall at the airport was 

35.38 in., 59.61 in., and 49.44 in., during water years 

1990, 1991, and 1992, respectively. During water year 

1992, rainfall near the Winter Park chain of lakes was 

about average, but was about 10 in. less than average 

in 1990, and about 10 in. more than average in 1991. A 

graph of rainfall at Winter Park and water level in 

Lake Virginia during the 3 years of the study is shown 

in figure 7. 

The stage of Lake Virginia rapidly responds to 

rainfall as indicated in figure 8, which shows cumulative rainfall and lake stage with time during April 11-

12, 1992. Several storms contributed more than l in. of 

rainfall per day during that time. The stage of the lake 

rapidly responded to the first storm on April 11 and 

generally responds to rainfall within an hour after the 

rainfall event. The increase in lake stage between 8-

9 am on April 12 does not correspond to a rainfall 

event and could be the result of ground-water inflow 

or of rainfall from an earlier event in another part of 

Table 3. Surface-water data-collection sites in the Winter 

Park area 

[Map numbers are from figure 6. S, continuous stage; D, discharge computed; QW, bimonthly water-quality samples; ST, stormwater-inflow 

water-quality samples; SS, stage for selected storms; SD, discharge for 

selected storms; R, rainfall]

Map

number

Site

identification

number

Site name Data 

types

1 283452081212401 Lake Sue outflow canal at 

Lake Sue

S, D, QW

2 02234263 Lake Sue outflow canal at 

Winter Park

S, D, QW

3 283518081210201 Lake Virginia west QW

4 02234264 Lake Virginia staff gage S

5 283517081204001 Lake Virginia QW

6 283534081201801 Lake Mizell QW

7 283545081201901 Lake Mizell north QW

8 283556081204101 Lake Osceola south QW

9 283613081204501 Webster Dr. ST, SS, SD

10 283615081202801 Lake Osceola north QW

11 283617081200901 Elizabeth Dr. ST, SS, SD

12 283644081204901 Lake Maitland south QW

13 02234287 Park Lake outflow canal S, D, QW

14 283708081214201 Lake Maitland west QW

15 283709081210401 Lake Maitland north QW

16 02234299 Lake Minnehaha outflow 

canal

S, D, QW

17 283727081203501 Lake Maitland outflow S, D, QW

18 283542081204701 Winter Park Library R

the basin. Maximum stage of the lake during the study 

was about 66.94 ft and minimum stage was about 

64.84 ft.

Surface Inflow

Inflows from Lake Sue, Park Lake, and Lake 

Minnehaha were measured during the three water 

years. Continuous measurements of stage were made 

at sites 2, 13, and 16 (table 3 and fig. 6) and daily 

discharge was computed. The mean daily inflows for 

water years 1990-92 are as follows:

A hydrograph showing daily flow from Lakes 

Sue and Minnehaha and Park Lake is presented in 

figure 9. Negative flow as shown on the hydrograph 

for Lake Minnehaha results when water flows from 

Lake Maitland to Lake Minnehaha, instead of from 

Minnehaha to Maitland. This condition can occur 

during prolonged dry periods.

Stormflow

Direct measurement of stormflow runoff is 

difficult because more than 68 storm drains enter the 

Winter Park chain of lakes (fig. 3), making measurement of flow from all storm drains impractical. Therefore, runoff was calculated using data from the Lake 

Virginia stage hydrograph for rainfall events greater 

than 0.1 in., based on the assumption that rainfall 

amounts less than this threshold would not result in 

runoff. Runoff was estimated from the change in lake 

stage corrected for rainfall, and for inflow and outflow, 

with the assumption that the effects of evaporation and 

ground-water seepage during the event were negligible. The runoff rate calculated for 1990 was 4 in.; 

1991, 32 in.; and 1992, 15 in.

 The effects of variations in rainfall are evident 

from the estimated runoff values. Runoff was very low 

during 1990, which had 10 in. less than average 

(48 in.) rainfall; runoff was much greater in 1991 with 

rainfall 10 in. above average; and 1992, a year with 

average rainfall, had an estimated runoff of about 

15 in.

Lake Sue

(ft3/s)

Park Lake

(ft3/s)

Lake Minnehaha

(ft3/s)

Total

(ft3/s)

Total

(in.)

1990 4.8 0.8 1.0 6.6 56

1991 6.2 1.3 1.2 8.7 73

1992 5.9 1.0 1.1 8.0 67
Water Budget 15

Ground-Water Inflow

Lateral inflow of water from the surficial aquifer system to the lakes is an important component of 

the flow budget for the lakes, but probably the one 

with the most uncertainty. Flow occurs because of the 

head difference between the water table and the lake 

level. Lateral inflow occurs through approximately 

13 mi of lake shoreline (table 1). Surficial ground 

water flows laterally from all directions into the lakes, 

except in a few very localized areas where the lake 

level is higher than the water table. The relation 

64.0

67.5

64.5

65.0

65.5

66.0

66.5

67.0

LAKE STAGE, IN FEET ABOVE SEA LEVEL

O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1989 1990 1991 1992

0

16

4

2

6

8

10

12

14

RAINFALL, IN INCHES

O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S

1989 1990 1991 1992

Figure 7. Monthly rainfall at Winter Park Library and water level in Lake Virginia, water years 

1990-92.

between the lakes and the ground-water system is 

shown as a generalized section in figure 10. Surficial 

ground-water inflow to the lakes was calculated using 

Darcy’s equation and hydrogeologic data collected in 

1992. Because of uncertainties in some of the hydrogeologic parameters and the problem of applying data 

from one water year to other water years having very 

different hydrologic conditions, inflow was also calculated as the residual of the flow budget for each water 

year.

Inflow of surficial ground water to the lakes can 

be estimated using Darcy's equation in the form:
16 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Q = K I A (2)

where

Q is inflow, in cubic feet per day,

K is hydraulic conductivity, in cubic feet 

per day per square foot of cross sectional

area, which reduces to feet per day,

I is hydraulic gradient, dimensionless, and

A is area across which flow occurs, in feet

squared.

The horizontal hydraulic conductivity of the 

surficial sediments was estimated from the grain-size 

analysis of sediments collected from the bottoms of 

Lakes Virginia and Maitland (figs. 4 and 5). The 

predominate grain-size range for 10 of 13 samples was 

0

0.44

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0.22

0.24

0.26

0.28

0.30

0.32

0.34

0.36

0.38

0.40

0.42

CUMULATIVE RAINFALL AND CHANGE IN LAKE STAGE, IN INCHES

Change in lake stage

Rainfall

1800 2400 0600 1200 1800 2400

APRIL 11 APRIL 12

1992

Figure 8. Cumulative rainfall and change in stage of Lake Virginia, April 11-12, 1992.

.09 to 1.0 mm, typical of fine-to medium-grained sand. 

The hydraulic conductivity for a similar grain-size distribution, calculated from field permeability (Davis 

and DeWiest, 1966, figure 11.3 and table 11.1), is 

about 60 ft/d. Using the same relation, the hydraulic 

conductivity corresponding to the grain size distribution of the three samples that had a greater percentage 

of fine material is about 15 ft/d. The estimated range 

of hydraulic conductivity of the surficial sediments is 

therefore 15 to 60 ft/d. A uniform hydraulic conductivity of 20 ft/d was assumed for simplicity because the 

bottom sampling method probably was biased toward 

larger grain sizes.

 The hydraulic gradient that controls surficial 

ground-water seepage to and from a lake is determined 

by the head difference between the water table and the 
W

aterBudget17

0

70

10

20

30405060

DAILY DISCHARGE, IN CUBIC FEET PER SECOND O

O

NN

DD

JJ

FF

MM

AA

MM

JJ

JJ

AA

SS

OO

NN

DD

JJ

FF

MM

AA

MM

JJ

JJ

AA

SS

OO

NN

DD

JJ

FF

MM

AA

MM

JJ

JJ

AA

SS

19891989

19901990

19911991

19921992

LAKE SUE02234263 

02234287 283727081203501

02234299 

-612-4-2

02468

10

OO

NN

DD

JJ

FF

MM

AA

MM

JJ

JJ

AA

SS

OO

NN

DD

JJ

FF

MM

AA

MM

JJ

19891989

19901990

1919

LAKE MINNEHAHA

0

20

2468

1012141618

PARK LAKE

0

120

20406080

100

LAKE MAITLAND

Figure 9. Daily discharge from Lake Sue, Lake Minnehaha, Park Lake, and Lake Maitland, October 1, 1989-September 30, 1992 (loca

shown in fig. 6).
18 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

lake stage. The gradient was measured in FebruaryMay 1992 at 20 sites around the lakes (fig. 11) by 

measuring the head difference between the water table 

and the lake using a drive-point manometer. Gradient 

values ranged from -2.71 x 10-3 to 6.59 x 10-1

(table 4), with a median gradient value of 1.10 x 10-2. 

A negative gradient is an indication of water moving 

from the lake to the surficial aquifer, rather than from 

the surficial aquifer to the lake. Negative gradients 

occurred at sites 3, 6, 8, and 9; at site 2 the heads in the 

lake and the surficial aquifer were equal.

The effective lake depth across which groundwater inflow occurs is important to the calculation 

because the area (A) in equation 2 is computed by 

multiplying the total length of lake shoreline by the 

effective depth. The effective depth depends on lake 

morphology and the relation of the local flow system 

to regional flow and may be difficult to estimate.

Kerfoot (1984) used an effective depth of 15 ft for a 

pond in glacial outwash on Cape Cod, Massachusetts.

In a study of Lake Lucerne in Polk County, Florida, an 

effective depth of 16 ft was used (T. Lee, U.S. 

Geological Survey, written commun., 1993). The 

topography around Lake Lucerne has more relief than 

that around the Winter Park chain of lakes. Based on 

methodology described by McBride and Pfannkuch 

(1975), the effective depth across which flow occurs in 

the Winter Park lakes was estimated to be 10 ft.

Total annual inflow calculated using a horizontal hydraulic conductivity of 20 ft/d and the median 

lateral hydraulic gradient of 1.10 x 10-2 was 17 in/yr. 

By comparison, the ground-water inflow for water 

year 1992 calculated as the residual of the flow budget 

was 40 in. Although the calculations based on Darcy’s 

equation were not used in the flow budgets, they are 

useful in pointing out the possible sources of error in 

ground-water flow estimates and the effect such errors 

might have on the flow and constituent budgets. For 

example, if the hydraulic gradient were increased one 

order of magnitude (while keeping the effective depth 

and hydraulic conductivity the same), the calculated 

inflow rate would have been 170 in/yr. On the other 

hand, if the hydraulic conductivity were increased 

from 20 to 40 ft/d and the hydraulic gradient and effective depth kept the same, the calculated inflow would 

have been 34 in/yr. 

Output

Water from the lakes is lost to evaporation and 

to surface and ground-water outflow. Only surface 

outflow can easily be measured directly.

Lake Evaporation

Evaporation of water from lake surfaces is an 

important element of the flow budget. The rate of 

evaporation depends on many factors, including 

temperature, the amount of solar radiation, vapor pressure, and wind speed at a particular site. Some water 

also is transpired by plants, so the lake evaporation 

rate may depend on the amount and type of vegetation 

present. In the following discussion the term lake 

evaporation refers to the total loss of water by evaporation and transpiration. A common way to estimate 

lake evaporation is to measure evaporation from a 

standard pan and then derive an empirical relation 

between observed pan evaporation and estimated lake 

evaporation.

Monthly rainfall, pan evaporation, and stage of 

Lake Virginia were measured in 1977 (Ross, 1979, 

p. 48). The best correlation between lake stage and pan 

evaporation determined in that study resulted from 

estimating evaporation to be 0.8 times pan evaporation. This correlation compares favorably with the 

mean annual pan-to-lake-coefficient of 0.81 calculated 

for Lake Okeechobee by Kohler (1954, table 24).

Monthly coefficients calculated in that study ranged 

from 0.69 for February to 0.91 for July and August.

A detailed study of evaporation was made at 

Lake Lucerne in Polk County (T. Lee, U.S. Geological 

Survey, written commun., 1993). Measurements of 

lake and ground-water levels, rainfall, and pan evaporation were made for the 1986 water year (October 1, 

1985, to September 30, 1986). During that year, 

Figure 10. Relation of water table to potentiometric surface 

of the Upper Floridan aquifer and components of groundwater flow.

LATERAL INFLOW

WATER TABLE

NOT TO SCALE

LAND SURFACE

SURFICIAL AQUIFER

SYSTEM

(UNCONSOLIDATED

SEDIMENTS)

UPPER FLORIDAN AQUIFER

(LIMESTONE)

VERTICAL OUTFLOW

POTENTIOMETRIC SURFACE OF THE UPPER FLORIDAN AQUIFER

?

?

?

? ?

? ?

?

?

?
Water Budget 19

0

0 .5 1 KILOMETER

.5 1 MILE

28 ̊38 ́

81 ̊22 ́ 21 ́ 81 ̊20 ́

37 ́

36 ́

28 ̊35 ́

Park

Lake

Lake

Sybelia

Lake

Minnehaha

Howell

Lake

Maitland

Lake

Sue

Lake

Berry

Horatio Ave.

Howell Branch Rd.

Park Ave.

Park Ave.

Palmer Ave.

Aloma Ave.

Winter Park

Library

Fairbanks Ave.

Osceol a Ave.

Rollins

College

Mead

Garden

Creek

Park

Lake Lake

Maitland

Lake

Osceola

Lake

Mizell

Lake

Virginia

Lake

Sue

Orange Ave.

20

18

19

17

16

14

12

13

11

10

9

8

6 7

4

4

1 2

3 5

15

EXPLANATION

SURFICIAL-AQUIFER DATA

REPORTED SEPTIC TANK

COLLECTION SITE AND

NUMBER FROM TABLE 4

LOCATION

92

17

Figure 11. Surficial aquifer data-collection sites and reported septic tank locations.
20 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

respectively. Evaporation rates calculated as 

80 percent of pan evaporation were 50.3, 48.5 and 

46.9 in. Because there is some uncertainty in the evaporation rates, 51 in. was used for 1990 and 48 in. for 

1991 in order to balance the flow budgets.

Surface Outflow

Nearly all of the surface-water outflow from the 

Winter Park chain of lakes discharges through a canal 

controlled by a weir near site 17 into Howell Creek 

(fig. 6) except for rare reverse flow from Lake 

Maitland to Lake Minnehaha. Previously, discharge 

from Lake Maitland was estimated using a theoretical 

weir-design rating. To provide more accurate 

discharge estimates, a continuous stage recorder was 

installed and periodic discharge measurements made 

so that a stage-discharge rating could be determined. 

From May 30, 1991, to August 20, 1992, 5 discharge 

measurements were made at site 17:

Table 4. Surficial aquifer sampling sites and head difference between lakes and the surficial aquifer 

[Map numbers are from figure 12. in., inch; ft/ft, feet per foot]

Map

number

Site identification 

number Site name Description

Head

difference

(in.)

Gradient 

(ft/ft)

1 283503081203701 Lake Virginia S., Laurel Rd. 10 ft onshore 2.56 2.10 x 10-2

2 283506081202201 Lake Virginia S.E. 1 ft offshore 0 0

3 283523081202701 Lake Virginia N.E. 10 ft offshore -0.16 -1.31 x 10-3

4 283525081210001 Lake Virginia W., Lakeview Dr. 2 ft onshore 0.32 1.29 x 10-2

5 283527081201001 Lake Mizell S.E. 2 ft offshore 0.55 2.30 x 10-2

6 283537081202401 Lake Mizell S.W. 0.5 ft onshore -0.32 -5.20 x 10-2

7 283537081204101 Lake Virginia, Dinky Dock 9 ft onshore 0.83 7.69 x 10-3

8 283547081202201 Lake Mizell N. 0.5 ft onshore -0.59 -9.80 x 10-2

9 283549081203201 Lake Osceola S.E., Trismen Ter. 12 ft onshore -0.39 -2.71 x 10-3

10 283600081205001 Lake Osceola S.W., Canton Ave. 5 ft onshore 6.50 1.08 x 10-1

11 283610081204501 Lake Osceola, Webster Dr. 3 ft onshore 0.94 2.61 x 10-2

12 283617081200902 Lake Osceola N.E., Elizabeth Dr. 6 ft onshore 0.79 1.10 x 10-2

13 283625081203501 Lake Osceola N.W., Palmer Ave. 1 ft onshore 5.52 4.59 x 10-1

14 283630081205401 Lake Maitland S., Olde England Dr. 1 ft onshore 4.33 3.61 x 10-1

15 283641081202901 Lake Maitland, Alabama Dr. 1 ft offshore 7.88 6.59 x 10-1

16 283642081211101 Lake Maitland S., New York Ave. 10 ft onshore 0.87 7.25 x 10-3

17 283647081212301 Lake Maitland S.W., Green Cove Rd 2 ft onshore 1.77 7.40 x 10-2

18 283702081203701 Lake Maitland E., Pinetree Rd. 4 ft onshore 2.68 5.58 x 10-2

19 283713081214701 Ft. Maitland Park 5 ft offshore 0.39 6.50 x 10-3

20 283723081210201 Lake Maitland N., Adams Dr. 4 ft onshore 0.20 4.17 x 10-3

annual lake evaporation estimated from an energy 

budget was about 58 in., about 8 in. higher than longterm estimates for the region. The rate may have been 

higher than expected because of drier than normal 

conditions: rainfall for the 1986 water year at Lake 

Lucerne was about 10 in. less than normal. The lowest 

evaporation rate calculated from a weekly energy 

budget was about 0.04 in/d in early January 1986. The 

highest rate was about 0.26 in/d in early May 1986.

Pan evaporation at the National Oceanic and 

Atmospheric Administration (NOAA) weather station 

in Lisbon, Lake County, Florida (fig. 1), was used to 

estimate evaporation for the Winter Park lakes. Pan 

evaporation at Lisbon in May and July 1989 was 8.11 

and 8.87 in., respectively, compared to the maximum 

Lake Lucerne rate (0.26 in/d) which is equivalent to 

8.06 in/mo. The lowest rate at Lake Lucerne 

(0.04 in/d) corresponds to a monthly total of 1.24 in., 

compared to 1.98 in. at Lisbon in December 1989. 

Annual lake evaporation was estimated to be 0.8 times 

pan evaporation. Pan evaporation rates at Lisbon for 

water years 1990-92 were 62.88, 60.63 and 58.63 in., 
Water Budget 21

Outflow rates calculated for water years 1990-

92 were 20, 103, and 90 in., respectively. Daily discharge rates from Lake Maitland are shown in figure 

9.

Ground-Water Outflow

Water also leaves the Winter Park lakes by outflow to the ground-water system. Although some of 

the ground-water outflow occurs as lateral flow to the 

surficial aquifer system, most of the ground-water outflow occurs as downward leakage through the surficial 

and Miocene sediments to the underlying Upper 

Floridan aquifer (fig. 10).

The rate of downward leakage depends on the 

vertical hydraulic gradient (the head difference 

between the surficial and Upper Floridan aquifers per 

foot of sediments separating the two aquifers) and the 

hydraulic conductivity of those sediments. The leakage rate can be calculated directly using Darcy’s equation or it can be estimated from the recession of the 

lake-stage hydrograph. Leakage rates calculated using 

either method can then be compared to rates used in 

ground-water flow models. The rate of downward 

leakage was assumed to be constant throughout the 

year because both the lake level and the potentiometric 

surface respond similarly during the wet and dry 

seasons and the head difference remains relatively 

constant. Continuous stage measurements of Lake 

Virginia from October 1, 1989, to September 30, 1992, 

show that the lake stage fluctuated slightly more than 

4 ft (between 62.65 and 66.93 ft above sea level). 

During the same period, the potentiometric surface of 

the Upper Floridan aquifer fluctuated in a range of 

about 5 ft (from about 49 to 55 ft above sea level). The 

highest lake and potentiometric-surface levels usually 

occur at the end of the summer rainy season (August 

or September) and the lowest levels at the end of the 

winter dry season (May). Some lag can occur between 

changes in either the lake or potentiometric levels. The 

head difference between the lake and the Upper 

Floridan ranged from about 17 to 22 ft during 

1990-92.

Date Stage

(ft)

Discharge

(ft3/s)

05/30/91 66.54 45

06/17/91 66.20 8

07/15/91 67.00 95

08/06/91 66.40 26

08/20/92 66.76 58

It is assumed that there is negligible lateral 

inflow of surficial ground water to the lakes during dry 

periods so the change in lake stage during those times 

depends almost totally on loss of water to evaporation 

and to downward leakage. This assumption is based on 

the fact that the stage of Lake Virginia stops rising 

within 24 hours after a rainfall event. Additionally, the 

horizontal hydraulic gradient toward the lake is very 

low. During several short dry periods in 1991, the 

daily stage drop, minus the correction for evaporation, 

equalled about 0.09 in/d or about 33 in/yr of downward leakage. The rate of downward leakage from the 

lakes estimated from lake hydrographs is consistent 

with downward leakage rates from detailed groundwater flow models of the area (L.C. Murray, U.S. 

Geological Survey, oral commun., 1993).

The possible vertical leakage rates computed 

using Darcy’s equation can have a wide range of 

values because of the possible range of the estimated 

hydraulic conductivity and thickness of sediments separating the lake bottoms from the Upper Floridan 

aquifer. The sediment thickness can be estimated from 

the geophysical logs of nearby wells and probably 

ranges from about 75-150 ft. Because the surface of 

the Upper Floridan has been eroded, the altitude of the 

surface can vary widely, as shown schematically in 

figure 10. Using a head difference of 15 ft and an 

estimated sediment thickness of 100 ft, the gradient is 

0.15. For a thickness of 150 ft, the vertical hydraulic 

gradient is 0.10; and if the thickness is 50 ft, the 

gradient is 0.3.

Estimates of the vertical hydraulic conductivity 

of the sediments also can vary greatly. At Lake 

Lucerne in Polk Country, Florida, the vertical hydraulic conductivity calculated for sediments underlying 

the lake was 0.09 ft/d plus or minus 0.08 (T. Lee, U.S. 

Geological Survey, written commun., 1993). Hydraulic conductivity estimates for the Winter Park area 

from regional computer modeling range from 0.01 to 

0.03 ft/d with a confining-bed thickness of 100 ft 

(Tibbals, 1990, fig. 30). Downward leakage rates 

calculated using various combinations of these estimates of vertical hydraulic conductivity and sediment 

thickness range from 5 to more than 300 in/yr. 

Assuming a vertical head difference of about 15 ft, a 

sediment thickness of about 100 ft (resulting in a 

vertical gradient of 0.15) and a vertical hydraulic conductivity of 0.05 ft/d, the calculated leakage rate 

(about 33 in/yr) is consistent with the rate estimated 

from the hydrograph recession and with ground-water 
22 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

flow-modeling studies. Because the head difference, 

and thus the vertical hydraulic gradient, remained relatively constant, ground-water outflow was kept 

constant for the 3 water years while other components 

were adjusted slightly. For example, slight adjustments 

were made in the evaporation rate to balance the flow 

budgets.

Budget Summary

Annual flow budgets for the Winter Park chain 

of lakes were estimated for water years 1990-92 using 

the information described in the previous sections 

(table 5). Rainfall and surface inflow and outflow 

measured at the lakes are considered to be reliable. 

The calculated values of runoff and evaporation are 

estimated with less certainty. The most difficult components to estimate, and the least reliable, are the rates 

of ground-water inflow and outflow. In water year 

1990 (a dryer than average year), the ground-water 

inflow rate, calculated as the residual of the flow 

budget, was zero, which seems unlikely. Probably the 

actual evaporation rate was higher than estimated from 

pan evaporation for that year. 

Based on the mean values from water years 

1990-92, about 31 percent of the inflow to the Winter 

Park Lakes comes from rainfall, about 11 percent from 

stormflow, 42 percent from inflow through surface 

streams, and 16 percent from ground-water inflow. 

Evaporation accounts for about 32 percent of the outflow, ground water for about 21 percent, and outflow 

to surface streams about 46 percent. On average, there 

is no change in lake storage. The relative contributions 

by the flow budget components are shown in figure 

12. Using the 1992 total inflow rate for the lakes, 

170 in/yr (table 5), and the total volume of the lakes 

(48.4 x 107 ft3, table 1), the average residence time for 

the lakes is about 310 days.

Table 5. Estimated flow budgets for the Winter Park chain of lakes, water years 1990-92

[All measurements are in inches]

Inflow 1990 1991 1992 Mean Outflow 1990 1991 1992 Mean

Rainfall 38 58 48 48 Evaporation 51 48 47 49

Stormflow 4 32 15 17 Surface outflow 20 103 90 71

Surface inflow 56 73 67 65 Estimated ground-water outflow 33 33 33 33

Estimated ground-water inflow 0 28 40 23 Lake storage change -6 7 0 0

Total 98 191 170 153 Total 98 191 170 153

WATER QUALITY

Water-quality data, as well as flow data, are 

needed to calculate constituent budgets for the chain 

of lakes. Data from previous studies were examined 

and bimonthly samples were collected at sites in the 

lakes and at inflow sites for 3 years. Samples also were 

collected at different depths in the lakes in April and 

June 1992. Samples of surficial ground water were 

collected once and existing chemical data for precipitation were compiled. Water samples were collected 

using standard U.S. Geological Survey techniques 

described by Wood (1976) and Fishman and Friedman 

(1989).

Water samples from the Winter Park chain of 

lakes have been collected by the Orange County 

Environmental Protection Department and by 

personnel from Rollins College. Those sampling 

efforts were systematic and continued for time periods 

ranging from 4 to more than 20 years. Additionally, a 

few samples have been collected as part of other 

studies of the lakes made by consultants to the city of 

Winter Park.

The Orange County Environmental Protection 

Department has sampled numerous lakes on a quarterly 

SURFACE

OUTFLOW

71"

SURFACE

INFLOW

65"

S

T

O

R

M

F

L

O

W

17"

GW

OUT

33"

GW

IN

23"

Lakes

EVAP

49"

RAIN

48"

Figure 12. Mean flow-budget components.
Water Quality 23

basis since 1972. Samples are collected at the midpoints 

of each lake and usually at the surface, although 

occasional surface, mid-depth, and near-bottom samples 

are collected. The samples are analyzed for major ions, 

nutrients, metals, bacteria, chlorophyll, and plankton. 

The four lakes of the Winter Park chain are included in 

the county sampling network, but no analyses of the 

county data have been published.

The Biology Department of Rollins College 

began the first of several ecological studies of the 

Winter Park chain of lakes in 1976. The most comprehensive of these was made in cooperation with the city 

of Winter Park from 1984-88. Monthly samples of nearsurface and near-bottom water were collected at random 

locations in each lake beginning in October 1984. Sampling of Lakes Osceola and Maitland was discontinued 

after 2 years; sampling of Lakes Virginia and Mizell 

continued until June 1988. Field measurements of dissolved oxygen, temperature, specific conductance, and 

transparency (Secchi disk) were made. The samples 

were analyzed for pH, specific conductance, total 

Kjeldahl nitrogen (TKN, ammonia-plus-organic nitrogen), nitrate nitrogen, total phosphorus, orthophosphate, 

and alkalinity. In addition to water-quality sampling, the 

Rollins College study included sampling for bacteria, 

phytoplankton, zooplankton, benthic fauna, and fish 

species.

The data collected for Lakes Virginia and Mizell 

in the Rollins College study are summarized by Small, 

Richard, and Gregory (1988, p. 6-9 and table 4). They 

concluded that the water quality of Lakes Virginia and 

Mizell was similar. However, specific conductance was 

higher in Lake Mizell than in Lake Virginia; the mean 

of near-surface specific conductance in Lake Virginia 

for water years 1985-87 ranged from 181 to 209 μS/cm, 

compared to 251 to 267 μS/cm in Lake Mizell. They 

also noted seasonal changes in such constituents as dissolved oxygen, pH and specific conductance, and most 

nutrient concentrations in both lakes. 

The chlorophyll-a and Secchi-disk transparency 

data also were used to calculate Carlson indices, a measure of a lake’s trophic state (Carlson, 1977). Small and 

his colleagues (1988) concluded that the Carlson indices calculated for Lakes Virginia and Mizell indicate 

that the lakes are in the early stages of eutrophication.

Precipitation

Samples of rainfall have been collected and 

analyzed by the U.S. Geological Survey at several sites 

in Florida (Irwin and Kirkland, 1980). German (1983) 

analyzed samples of rainfall at Lake Hope in Maitland, 

Florida (fig. 1). No new analyses were made during this 

study.

The bulk precipitation sampled at Lake Hope 

(German, 1983) had a range of specific conductance 

from 13 to 58 μS/cm with a mean of 23 μS/cm. The pH 

of the samples ranged from 5.0 to 7.5 and chloride concentrations ranged from 0.6 to 2.7 mg/L, with a mean of 

1.6 mg/L. Total nitrogen ranged from 0.19 to 6.8 mg/L, 

with a mean of 1.6 mg/L, and total phosphorus ranged 

from 0.01 to 0.89 mg/L, with mean of 0.18 mg/L. Total 

organic carbon (TOC) ranged from 1.0 to 20 mg/L, with 

a mean of 4.0 mg/L. The samples collected at Lake 

Hope were composites collected over 3-mo periods. 

Because of uncertainties about the preservation of nutrient samples during the composite sampling periods, 

atmospheric deposition rates for Florida lakes given by 

Baker and others (1981) were used for nitrogen and 

phosphorus, rather than analyses of precipitation samples.

Surface Inflow and Lakes

The U.S. Geological Survey collected water samples bimonthly at 14 sites in the chain of lakes (fig. 6 

and table 3) from October 1989 to June 1992. Surfacewater discharge into or out of the lakes was sampled at 

five of the sites. The other sampling sites were distributed within the lakes. Field measurements of dissolved 

oxygen were made 1 ft below the water surface at each 

site. A depth-integrated sample was collected and field 

determinations were made of pH, specific conductance, 

and temperature. The samples were analyzed in the laboratory for major ions, nutrients, organic carbon, color, 

turbidity, alkalinity, and chlorophyll-a and -b. A series 

of samples also was collected from different depths in 

the lakes. In April 1992 samples from Lakes Virginia, 

Mizell, and Osceola were analyzed for the same constituents listed above. Samples collected in June 1992 in 

Lakes Virginia, Mizell, and Maitland were analyzed for 

pH, specific conductance, dissolved oxygen, and nutrients. All of the water-quality data collected during this 

study are listed in the appendix. A statistical summary 

of data for all surface-inflow and lake sites is shown in 

table 6. In the following discussion, the lake sites are 

emphasized. Data for the inflow, outflow, and lake sites 

(appendix and table 6) were used to calculate the constituent budgets.
24 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Table 6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92 [Concentrations are in milligrams per liter unless otherwise noted. Nitrogen species are reported as nitrogen (N); phosphorus species are reported as phosphorus (P). °C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; <, less than; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams p

Unit; μg/L, micrograms per liter; --, not reported] Water-quality constituent Site name and identification number Lake Sue outlet at Winter Park 02234263 Park Lake outlet 02234287 

Sample size Maxi- mum Mini-mum Median Sample size Maxi- mum Mini- mum Median Sample size 

Water temperature (°C) 17 31.0 13.5 24.5 15 31.0 13.5 27.0 15 Turbidity (NTU) 17 10.0 .17 .83 15 2.4 .15 .72 15 Color (Pt-Co Units) 17 25 <5 10..0a 15 30 5 10.0 15 Specific conductance (

μS/cm) 17 294 184 204 15 385 196 225 15 

Oxygen, dissolved (mg/L) 14 11 3.6 5.5 12 9.4 3.8 6.8 13 pH, Wh, field (SU) 17 8.0 6.8 7.4 15 8.5 6.9 7.4 15 Nitrogen, nitrite 17 .03 <.01 .01a 15 .04 <.01 .01a 15 Nitrogen, ammonia + organic 17 1.5 .48 .78 15 2.1 .59 .76 15 NO2 + NO3, total 17 .19 .04 .13 15 .60 <.02 .08a 15 Phosphorus, total 17 .09 <.01 .06a 15 .16 .04 .06 15 Carbon, organic, total 17 6.6 3.3 4.9 15 8.5 4.0 6.0 15 Calcium, dissolved 17 38 22 23 15 44 26 31 15 Magnesium, dissolved 17 7.5 3.1 4.0 15 6.3 3.1 3.5 15 Sodium, dissolved 17 11 7.8 9.8 15 18 7.1 8.0 15 Potassium, dissolved 17 2.7 1.7 2.2 15 4.3 2.0 2.7 15 Chloride, dissolved 17 19 14 16 15 36 12 13 15 Sulfate, dissolved 17 15 12 14 15 25 12 13 15 Fluoride, dissolved 2 .10 .10 -- 2 .10 .10 -- 2 Boron, total (

μg/L) 2 40 30 -- 2 50 40 -- 2 

Molybdenum total (

μg/L) 2 2.0 1.0 -- 2 2.0 1.0 -- 2 

Phosphorus, ortho, total 17 .07 <.01 .02a 15 .08 <.01 .03a 15 Alkalinity (mg/L as CaCO3) 17 11 50 57 15 103 64 79 15 
Water Quality 25

Table 6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92--Continued[Concentrations are in milligrams per liter unless otherwise noted. Nitrogen species are reported as nitrogen (N); phosphorus sreported as phosphorus (P). °C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; <, less tha

microsiemens per centimeter at 25 °C ; mg/L, milligrams per liter; Wh, whole water; SU, Standard Unit; μg/L, micrograms pe

not reported] 

Water-quality constituent

Site name and identification number

Lake Maitland outflow

283727081203501

Lake Sue outflow canal at Lake S

283452081212401

Sample 

size

Maximum Mini-mum Median Sample size Maxi- mum Mini- mum Med

Water temperature (°C) 9 30.5 13.0 27.5 14 33.0 17.0 26.

Turbidity (NTU) 9 3.0 .56 1.7 14 4.2 -- 

Color (Pt-Co Units) 9 30 5.0 20 14 15 <5 10Specific conductance (μS/cm) 9 300 192 203 14 210 167 185Oxygen, dissolved (mg/L) 8 8.1 5 6.0 12 9.5 5.4 7.pH, Wh, field (SU) 9 9.0 7.3 7.6 14 9.1 7.3 8.Nitrogen, ammonia 9 .40 <.01 .02a 14 .09 <.01 Nitrogen, nitrite 9 .16 <.01 .01a 14 .01 <.01 Nitrogen, ammonia + organic 9 1.7 .61 .95 14 1.8 .52 NO2 + NO3, total 9 .44 <.02 .02a 14 .09 <.02 Phosphorus, total 9 .14 <.01 .04a 14 .05 <.01 Carbon, organic, total 9 9.2 4.6 6.1 14 6.4 3.7 5.Calcium, dissolved 9 40 21 22 14 24 18 21Magnesium, dissolved 9 4.7 3.0 4.0 14 3.6 2.7 3.Sodium, dissolved 9 11 7.8 9.3 14 12 8.2 10.Potassium, dissolved 9 4.0 2.2 2.9 14 2.8 1.9 2.Chloride, dissolved 9 21 14 18 14 19 14 18Sulfate, dissolved 9 20 9.3 15 14 17 13 14Fluoride, dissolved 2 .10 .10 -- 2 .10 10.0 --Boron, total (μg/L) 2 40 40 -- 2 50 40 --

Molybdenum, total (μg/L) 2 -- -- -- 2 -- -- --

Phosphorus, ortho, total 9 .08 <.01 .02a 14 .03 <.01 

Alkalinity (mg/L as CaCo3) 9 105 47 50 14 56 42 49
26 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Table 6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92--Continued [Concentrations are in milligrams per liter unless otherwise noted. Nitrogen species are reported as nitrogen (N); phosphorus species are reported as phosphorus (P). °C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; <, less than; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams p

Unit; μg/L, micrograms per liter; --, not reported] Water-quality constituent Site name and identification number Lake Virginia 283517081204001 Lake Virginia West 283518081210201 

Sample size Maxi-mum Mini- mum Median Sample size Maxi- mum Mini- mum Median Sample size 

Water temperature (°C) 16 33.0 17.0 25.7 14 32.5 18.0 25.5 16 

Turbidity (NTU) 16 4.4 .13 1.3 14 4.4 .15 1.3 16 Transparency (inches) 16 78 20 40 14 76 20 40 16 Color (Pt-Co Units) 16 20 <5 10.0a 14 20 <5 10.0a 16 

Specific conductance (

μS/cm) 16 231 191 202 14 231 192 204 15 

Oxygen, dissolved (mg/L) 14 10.0 6.7 8.9 13 10.0 6.4 9.0 14 pH, Wh, field (SU) 16 9.1 7.6 8.2 14 9.1 7.7 8.3 16 Nitrogen, ammonia 16 .07 <.01 .01a 14 .08 <.01 .01a 16 Nitrogen, nitrite 16 -- <.01 -- 14 -- <.01 -- 16 Nitrogen, ammonia + organic 16 1.7 .52 .82 14 1.6 .57 .79 16 NO2 + NO3, total 16 -- <.02 -- 14 -- <.02 -- 16 

Phosphorus, total 16 .05 <.01 .03a 14 .05 <.01 .03a 16 

Carbon, organic, total 16 6.6 3.5 5.0 14 6.5 3.7 5.0 16 Calcium, dissolved 16 27 21 23 14 27 21 23 16 Magnesium, dissolved 16 4.7 3.6 4.0 14 4.7 3.5 4.0 16 Sodium, dissolved 16 11 8.6 9.9 14 11 9.0 10 16 Potassium, dissolved 16 3.0 2.2 2.6 14 2.9 2.1 2.6 16 Chloride, dissolved 16 19 15 17 14 19 16 18 16 Sulfate, dissolved 16 17 14 15 14 18 15 16 16 Fluoride, dissolved 2 .10 .10 -- 2 .10 .10 -- 2 Boron, total (

μg/L) 2 50 30 -- 2 40 40 -- 2 

Molybdenum, total (

μg/L 2 2.0 2.0 -- 2 2.0 2.0 -- 2 

Phosphorus, ortho, total 16 .02 <.01 .01a 14 .02 <.01 .01a 16 Chlorophyll-a phytoplankton (

μg/L) 15 32 4.3 14 13 28 5.6 15 15 

Chlorophyll-b phytoplankton (

μg/L) 15 1.7 -- .60a 13 2.0 -- .50a 15 

Alkalinity (mg/L as CaCO3) 16 66 50 54 14 66 52 56 16 
Water Quality 27

Table 6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92--Continued[Concentrations are in milligrams per liter unless otherwise noted. Nitrogen species are reported as nitrogen (N); phosphorus species are reported a°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; <. less than; μS/cm, microsiemens per centimeter at 25 °C; whole water; SU, Standard Unit; μg/L, micrograms per liter; --, not reported]

Water-quality constituent

Site name and identification number

Lake Mizell North

283545081201901

Lake Osceola South

283556081204101

Sample 

size

Maximum Mini- mum Median Sample size Maxi- mum Mini- mum Median Sample size 

Water temperature (°C) 15 32.5 18.0 25.5 16 32.0 17.5 25.5 16 

Turbidity (NTU) 14 3.9 .24 .80 16 2.3 .27 1.0 16 Transparency (inches) 14 98 18 44 16 62 19 39 16 Color (Pt-Co Units) 14 20 <5 7.5a 16 20 <5 5.0a 16 

Specific conductance (μS/cm) 15 259 226 250 16 233 194 208 16 

Oxygen, dissolved (mg/L) 14 10.0 5.9 9.2 14 11 6.1 9.0 14 Ph, Wh, field (SU) 15 9.4 7.5 8 16 9.2 7.5 8.2 16 Nitrogen, ammonia 14 .22 <.01 .01a 16 .30 <.01 .01a 16 

Nitrogen, nitrite 14 -- <.01 -- 16 -- -<.01 -- 16 Nitrogen, ammonia + organic 14 1.7 .51 .99 16 1.7 .70 .90 16 NO2 + NO3, total 14 -- <.02 -- 16 -- <.02 -- 16 

Phosphorus, total 14 .06 <.01 .03a 16 .16 <.01 .03a 16 

Carbon, organic, total 14 7.9 3.1 5.6 16 6.8 1.4 5.2 16 Calcium, dissolved 14 23 21 23 16 27 21 24 16 Magnesium, dissolved 14 7.0 5.8 6.4 16 4.7 3.8 4.2 16 Sodium, dissolved 14 11 8.8 9.6 16 11 8.5 9.7 16 Potassium, dissolved 14 9.3 7.4 8.2 16 2.9 2.2 2.6 16 Chloride, dissolved 14 25 21 24 16 19 16 18 16 Sulfate, dissolved 14 36 27 30 16 19 15 16 16 Fluoride, dissolved 2 0.10 0.10 -- 2 0.10 0.10 -- 2 Boron, total (μg/L) 2 70 50 -- 2 50 30 -- 2 Molybdenum, total (μg/ L) 2 -- -- -- 2 3.0 2.0 -- 2 

Phosphorus, ortho, total 14 .03 <.01 .01a 16 .03 <.01 .01a 16 

Chlorophyll-a phytoplankton (μg/L 13 31 3.5 9.6 15 36 5.6 17 15 

Chlorophyll-b phytoplankton (μg/L) 3 1.4 <.1 .30a 15 1.2 <.1 .80a 15 

Alkalinity (mg/L as CaCO3) 14 50 41 46 16 81 52 57 16 
28 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Table 6. Statistical summary of selected water-quality data for the Winter Park chain of lakes, 1989-92 --Continued [Concentrations are in milligrams per liter unless otherwise noted. Nitrogen species are reported as nitrogen (N); phosphorus species are reported as phosphorus (P). °C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; <, less than; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams p

Unit; μg/L, micrograms per liter; --, not reported] Water-quality constituent Site name and identification number Lake Maitland South 283644081204901 Lake Maitland West 283708081214201 

Sample size Maxi- mum Mini- mum Median Sample size Maxi- mum Mini- mum Median Sample size 

Water temperature (°C) 16 31.5 17.0 25.5 14 31.0 17.5 25.5 16 

Turbidity (NTU) 16 3.9 .17 1.0 14 4.1 .19 1.4 16 Transparency (inches) 16 68 27 43 14 65 28 41 16 Color (Pt-Co Units) 16 20 <5 5.0a

aValue is estimated by using a log-probability regression to predict the values of data below the detection limit.

If the number of observations above the detection limit is less than 5, the estimated values are considered unreliable and are not reported.

If the number of observations is greater than 1 and less than or equal to 5, only the maximum and minimum are reported.If the number of observations is equal to 1, only the maximum is reported.

14 20 <5 10a 16 

Specific conductance (

μS/cm) 16 228 195 208 14 230 190 206 16 

Oxygen, dissolved (mg/L) 14 9.6 6.1 8.5 13 10.0 6.6 7.9 14 Ph, Wh, field (SU) 16 8.8 7.3 8.0 14 9.1 7.6 8.1 16 Nitrogen, ammonia 16 .13 <.01 .01a 14 .05 <.01 .01a 16 Nitrogen, nitrite 16 -- <.01 -- 14 -- <.01 -- 16 Nitrogen, ammonia + organic 16 1.4 .47 .80 14 1.6 .63 .82 16 NO2 + NO3, total 16 -- <.02 -- 14 -- <.02 -- 16 

Phosphorus, total 16 .06 <.01 .03a 14 .06 <.01 .04a 16 

Carbon, organic, total 16 6.6 1.2 5.2 14 6.5 4.3 5.5 16 Calcium, dissolved 16 25 22 23 14 25 21 22 16 Magnesium, dissolved 16 4.4 3.8 4.1 14 4.4 3.6 4.0 16 Sodium, dissolved 16 11 8.7 10.0 14 11 8.8 10.0 16 Potassium, dissolved 16 3.4 2.2 2.9 14 4.8 2.2 3.0 16 Chloride, dissolved 16 21 16 19 14 21 17 19 16 Sulfate, dissolved 16 20 16 18 14 21 15 18 16 Fluoride, dissolved 2 0.10 0.10 -- 2 0.10 0.10 -- 2 Boron, total (

μg/L) 2 50 30 -- 2 50 30 -- 2 

Molybdenum, total (

μg/L) 2 2.0 2.0 -- 2 2.0 2.0 -- 2 

Phosphorus, ortho, total 16 .03 <.01 .01a 14 .03 <.01 .01a 16 Chlorophyll-a phytoplankton (

μg/L) 15 26 5.0 12 13 19 5.8 12 15 

Chlorophyll-b phytoplankton (

μg/L) 15 1.2 <.1 .30a 13 .90 <.1 .30a 15 

Alkalinity (mg/L as CaCO3) 16 55 -- 52a 14 54 48 51 16 
Water Quality 29

Field Measurements

Properties of surface inflow and lake water 

measured in the field included dissolved oxygen, pH, 

temperature, specific conductance, and Secchi-disk 

depth. Those properties generally varied with lake 

stage and season, and, to some extent, from lake to 

lake. For the purpose of comparing the water quality 

characteristics of the lakes, the median concentrations 

185

265

190

195

200

205

210

215

220

225

230

235

240

245

250

255

260

SPECIFIC CONDUCTANCE, IN MICROSIEMENS

O N D J FM A M J J A S O N D J FM A M J J A S ON D J FM A M J J A S

1989 1990 1991 1992

O N D J FM AM J J A SOND J FM AM J J AS ON D J F MAM J J AS

1989 1990 1991 1992

LAKE MAITLAND

LAKE OSCEOLA

LAKE MIZELL

LAKE VIRGINIA

64

68

65

66

67

LAKE STAGE, IN FEET

ABOVE SEA LEVEL

LAKE VIRGINIA

Figure 13. Median specific conductance of the Winter Park lakes and stage of Lake Virginia, 

1989-92.

for all sites in each lake on each sampling date was 

used. For example, the median of the three sites in 

Lake Maitland was compared with the medians of the 

two sites each in Lakes Mizell, Osceola and Virginia.

Specific conductance ranged from about 190 

to about 230 μS/cm for Lakes Maitland, Osceola, 

and Virginia and from 226 to 260 μS/cm in Lake 

Mizell (fig. 13). The higher specific conductance in 

Lake Mizell is probably because it is isolated from 
30 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

the surface-water flow system of the other 3 lakes. 

There is no surface inflow to Lake Mizell, only 

direct stormflow from land around the lake, stormflow from 9 storm drains, and ground-water inflow. 

The peak of specific conductance in all 4 lakes 

occurs at about the same time as the lowest lake 

stage measured during the study in March 1991. 

This probably is because during very dry weather 

there is little inflow of surface-water or stormflow, 

10

130

20

30

40

50

60

70

80

90

100

110

120

SECCHI DISK DEPTH, IN INCHES

O N D J FM A M J J A S O N D J FM AM J J A S O N D J FM AM J J A S

1989 1990 1991 1992

LAKE MAITLAND LAKE OSCEOLA

LAKE MIZELL

LAKE VIRGINIA

O N D J FM A M J J A S O N D J F M A M J J A S O N D J FM AM J J A S

1989 1990 1991 1992

68

64

65

66

67

LAKE STAGE, IN FEET

ABOVE SEA LEVEL

LAKE VIRGINIA

Figure 14. Median Secchi disk depth for the Winter Park lakes and stage of Lake Virginia, 1989-92.

which generally have a lower specific conductance 

than ground water.

Secchi-disk depth, which is a measure of the 

transparency of the lake water, fluctuates seasonally, 

but does not seem to be related to fluctuations in lake 

stage (fig. 14). The highest Secchi-disk values 

(indicating the clearest water) generally occurred in 

February-March and might be related to the dying of 

algae in the winter.
Water Quality 31

 Dissolved oxygen concentration also fluctuates 

seasonally and probably is related to productivity of 

algae. Generally, the lowest dissolved oxygen 

concentrations occur in the summer when water 

temperature is highest (figs. 15 and 16), although the 

amount of rainfall which affects lake flushing also can be 

important. For example, the relatively high dissolved 

oxygen concentrations in June 1991 could have been due 

to the large spring and early summer rainfall amounts. 

5.0

11.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

DISSOLVED OXYGEN, IN MILLIGRAMS PER LITER

O N D J FM A M J J A S O N D J FM AM J J A S ON D J FM A M J J A S

1989 1990 1991 1992

O N D J FM A M J J A S O N D J FM A M J J A S ON D J FM A M J J A S

1989 1990 1991 1992

64

68

65

66

67

LAKE STAGE, IN FEET

ABOVE SEA LEVEL

LAKE VIRGINIA

LAKE MAITLAND

LAKE OSCEOLA

LAKE MIZELL

LAKE VIRGINIA

Figure 15. Median dissolved oxygen concentrations for the Winter Park lakes and stage of Lake 

Virginia, 1989-92.

Because of the subtropical climate in central Florida and 

the relatively shallow lake depths, the lakes are not stratified and do not exhibit the spring and fall turnover (disappearance of thermal stratification) observed in lakes in 

temperate climates. Dissolved oxygen concentrations in 

the water of the Winter Park chain of lakes generally are 

higher than the 5 mg/L standard for the preservation of 

aquatic habitats in surface waters established by the 

Florida Department of Environmental Protection (1983).
32 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Some comparisons between the characteristics 

of the largest lake (Maitland) and the smallest (Mizell) 

were also made (fig. 16). As mentioned previously, the 

specific conductance of water in Lake Mizell is generally higher than in Lake Maitland. The temperature of 

the two lakes is similar. Dissolved oxygen concentrations generally follow a similar trend, although from 

August 1990 to August 1991 dissolved oxygen was 

consistently higher in Lake Mizell than in Lake 

Maitland. During that time, chlorophyll-a concentraFigure 16. Temperature, Secchi disk depth, and dissolved oxygen and chlorophyll-a concentrations for 

Lakes Maitland and Mizell, 1989-92.

35

15

20

25

30

TEMPERATURE,

IN DEGREES CELSIUS

ON D J F M AM J J AS O N D J F M A M J J A S O N D J F M AM

1989 1990 1991 1992

ON D J F M AM J J AS O N D J F M A M J J A S O N D J F M AM

1989 1990 1991 1992

ON D J F M AM J J AS O N D J F M A M J J A S O N D J F M AM

1989 1990 1991 1992

ON D J F M AM J J AS O N D J F M A M J J A S O N D J F M AM

1989 1990 1991 1992

Lake Maitland

Lake Maitland

Lake Maitland

Lake Maitland

Lake Mizell

Lake Mizell

Lake Mizell

Lake Mizell

4

12

6

8

10

DISSOLVED OXYGEN,

IN MILLIGRAMS PER LITER

0

30

10

20

-a CHLOROPHYLL CONCENTRATION,

IN MILLIGRAMS PER LITER 150

0

50

100

SECCHI DISK DEPTH, IN INCHES

tions in Mizell were lower than in Maitland, except for 

a peak in Mizell in late April 1991. Secchi-disk depths 

in both lakes were similar except for the unusually 

high value in Mizell in late February 1990. 

Chemical and Biological Characteristics

The bimonthly sampling of surface inflow and 

lake sites also included analysis for major ions 

(calcium, sodium, magnesium, potassium, chloride, 
Water Quality 33

sulfate, and fluoride), nutrients (nitrogen and phosphorus), organic carbon, and chlorophyll-a and -b. Major 

ion concentrations were similar for all the lakes except 

for magnesium, potassium, and sulfate concentrations 

in Lake Mizell (table 6 and fig. 17). Those constituents 

were noticeably higher in Lake Mizell, which is consistent with the generally higher specific conductance 

in the lake. Although total nitrogen was about the 

same in Lake Mizell as in the other lakes, chlorophyll-a concentrations were somewhat lower and 

Secchi-disk transparency generally was higher than in 

the other lakes. 

Concentrations of total ammonia-plus-organic 

nitrogen ranged from 0.470 to 1.7 mg/L, with median 

concentrations in all lakes ranging from 0.79 to 

0.99 mg/L (table 6). Nitrate, nitrite, and ammonia 

concentrations were low (most were less than the laboratory detection limit), indicating that most of the 

nitrogen in the lakes is organic nitrogen. Median total 

phosphorus concentrations ranged from 0.02 to 

0.20 mg/L. The fluctuation of median total Kjeldahl 

nitrogen and total phosphorus concentrations for all 

the sites in each lake and the stage of Lake Virginia are 

shown in figure 18. The nitrogen concentrations in all 

the lakes generally follow a similar trend with time, as 

do the phosphorus concentrations, but the trends of 

both nutrient concentrations in any particular lake usually are not the same. An exception is from MarchAugust 1991 when nitrogen and phosphorus concentrations both increased in the early part of the summer, 

then decreased in August. No relation between 

nutrient concentrations and lake stage is apparent from 

the graphs.

Samples were collected at different depths in 

April and June 1992 to determine the variations of 

major ion and nutrient concentrations with depth. 

Water samples from the deepest levels had lower temperature and dissolved oxygen, and higher specific 

conductance and ammonia concentrations (tables 7 

and 8). Total phosphorus concentrations were slightly 

higher in the water samples from deeper levels, but 

total orthophosphorus concentrations were about the 

same. In April dissolved oxygen concentrations near 

the lake bottoms ranged from 0.2 to 5.1 mg/L but in 

June, when the water was warmer, all bottom concentrations were 0.2 mg/L or less. Ammonia concentrations were higher in deeper water samples, especially 

in June, when ammonia concentrations exceeding 

1 mg/L were found at several sites. The higher 

ammonia concentrations in deeper water samples 

probably are the result of the low dissolved oxygen 

concentrations in those samples. 

Fluctuations in nutrient concentrations might be 

expected to influence the concentrations of phytoplankton (algae) in lakes. Chlorophyll-a is the 

primary photosynthetic pigment of all oxygenproducing green plants and is present in all algae 

(Greeson and others, 1977, p. 209). A measurement of 

chlorophyll-a concentration is therefore an indicator of 

the quantity of living microorganisms (biomass) in an 

aquatic environment, which can in turn be an indicator 

of water quality. Chlorophyll-a concentrations might 

be expected to fluctuate seasonally, but their variation 

seems to be more complex (fig. 19). For example, a 

peak of chlorophyll-a concentration occurred in Lake 

Osceola in March 1990, while levels in the other lakes 

were relatively low. High levels occurred in all the 

lakes during the summer of 1991, a year with higher 

than average rainfall. Chlorophyll-a seems to increase 

with temperature and increased lake levels, possibly 

associated with increased discharge and nutrient loading.

Time Trends

There has been concern that nutrient concentrations have been increasing in the Winter Park chain of 

lakes. To examine possible long-term trends, data were 

retrieved from the U. S. Environmental Protection 

Agency’s (USEPA) STORET data base, which 

includes data collected by Orange County Environmental Control and the U. S. Geological Survey. Data 

collected by Rollins College from 1984-87 apparently 

were not included in STORET, so those data do not 

appear on the plots. The nitrogen and phosphorus data 

collected by Rollins College for Lake Virginia were 

compared to the data from STORET. Nitrogen data fit 

the plot of STORET data very well, but there is more 

scatter in the Rollins phosphorus data than in the 

STORET data. Plots of total nitrogen, total phosphorus 

and chlorophyll-a concentrations and Secchi-disk 

transparency are shown for each lake in figures 20a.-

20d. There is some evidence for decreasing Secchidisk transparency in Lakes Maitland and Virginia and 

increasing chlorophyll-a in Lake Maitland. In Lake 

Virginia, there are not as many early chlorophyll-a

samples, so a trend is not apparent. Phosphorus and 

transparency had somewhat cyclic patterns but no 

apparent increasing trends. The nitrogen data were 

more ambiguous, possibly showing increasing trends 

in Lakes Virginia and Mizell.
34 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Figure 17. Range of medians of selected water-quality constituents for the Winter Park lakes (total phosphorus concentrations less 

than the detection limit of 0.01 mg/L are plotted as 0).

0

40

10

20

30

0

125

EXPLANATION

25

50

75

100

0

2.0

0.5

1.0

1.5

0

0.10

0.02

0.04

0.06

0.08

IN MILLIGRAMS PER LITER

TOTAL NITROGEN,

IN MILLIGRAMS PER LITER

TOTAL PHOSPHOROUS,

Lake Maitland

Lake Osceola

Lake Mizell

Lake Virginia

Lake MaitlandLake Osceola

Lake Mizell

Lake Virginia

Lake MaitlandLake Osceola

Lake Mizell

Lake Virginia

IN MICROGRAMS PER LITER

-a, CHLOROPHYLL

SECCHI-DISK DEPTH,

IN INCHES

Maximum Median Minimum

0

5

10

15

20

25

30

0

40

10

20

30

0

300

50

100

150

200

250

0

80

20

40

60

SPECIFIC CONDUCTANCE, IN

ALKALINITY, IN MILLIGRAMS PER

LITER AS CALCIUM CARBONATE

MICROSEIMENS PER CENTIMETER

SULFATE,

IN MILLIGRAMS PER LITER

CHLORIDE,

IN MILLIGRAMS PER LITER

0

12

2

4

6

8

10

0

10

2

4

6

8

0

30

5

10

15

20

25

0

8

2

4

6

CALCIUM,

IN MILLIGRAMS PER LITER

MAGNESIUM,

IN MILLIGRAMS PER LITER

SODIUM,

IN MILLIGRAMS PER LITER

POTASSIUM,

IN MILLIGRAMS PER LITER
Water Quality 35 MEDIAN TOTAL KJELDAHL NITROGEN CONCENTRATION, IN MILLIGRAMS PER LITER

MEDIAN TOTAL PHOSPHORUS CONCENTRATION, IN MILLIGRAMS PER LITER 0.10

0

0.02

0.04

0.06

0.08

0

0.10

0.02

0.04

0.06

0.08

0

0.10

0.02

0.04

0.06

0.08

64

68

65

66

67

LAKE STAGE, IN FEET

ABOVE SEA LEVEL

ON D J F MAM J J A SO N D J FMA M J J A SON D J F M AM J J AS

1989 1990 1991 1992

ON D J F MAM J J A SO N D J FMA M J J A SON D J F M AM J J AS

1989 1990 1991 1992

ON D J F MAM J J A SO N D J FMA M J J A SON D J F M AM J J AS

1989 1990 1991 1992

ON D J F MAM J J A SO N D J FMA M J J A SON D J F M AM J J AS

1989 1990 1991 1992

ON D J F MAM J J A SO N D J FMA M J J A SON D J F M AM J J AS

1989 1990 1991 1992

0.5

2.0

1.0

1.5

0.5

2.0

1.0

1.5

0

2.0

0.5

1.0

1.5

0.6

1.6

0.8

1.0

1.2

1.4

0.10 1.6

0

0.02

0.04

0.06

0.08

Total phosphorus

Total phosphorus

Total phosphorus

Total phosphorus

Total Kjeldahl nitrogen

Total Kjeldahl nitrogen

Total Kjeldahl nitrogen

Total Kjeldahl nitrogen

LAKE MAITLAND

LAKE OSCEOLA

LAKE MIZELL

LAKE VIRGINIA

LAKE VIRGINIA 

Figure 18. Median total phosphorus and total Kjeldahl nitrogen concentrations for the Winter Park lakes and stage of 

Lake Virginia, 1989-92 (total phosphorus concentrations less than the detection limit of 0.01 mg/L are plotted as 0).
36 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Table 7. Water-quality variations with sampling depth in the Winter Park chain of lakes, April 1, 1992 [°C, degrees Celsius; NTU, nephelometric turbidity units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; <, less than; --, not determined] Samp- ling depth (feet) Tem- pera- ture, water

(°C)

Turbidity

(NTU)

Color

(platinumcobalt

units)

Specific

 conductance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH 

wholewater, 

field 

(standardunits)

Nitrogen, ammonia 

total

(mg/L as N)

Nitrogen, 

nitrite 

total 

(mg/L 

as N)

Nitrogen, ammonia + 

organic 

total 

(mg/L as N)

Nitrogen

NO2

+NO3

total

(mg/L as N)

Phosphorus, 

total

 (mg/L

 as P)

Carbon, 

organic 

total 

(mg/L as C)

Calcium, 

dissolved 

(mg/L 

as Ca)

Magnesium,

 dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L) 

as Na)

Potassium, 

dissolved

(mg/L 

as K)

Chl

rid

dis

solv

(mg

 as C

Lake Virginia (site number 283513081203700)

1.7 22.5 1.4 10 202 10.8 9.1 .01 <.01 .95 <.02 .08 5.7 22 4.0 10.0 2.7 19 8.7 21 -- -- 201 9.6 8.8 .01 <.01 .86 <.02 .08 4.6 -- -- -- -- -- 

19.0 20.5 2.0 10 203 5.1 7.3 0.050 <0.010 0.91 <0.020 0.080 5.0 23 3.9 9.6 3.0 19 

Lake Mizell North (site number 283545081201901)

1.0 23.0 2.0 10 249 10.0 8.7 .01 <.01 .78 <.02 .09 5.0 23 6.6 9.6 8.4 24 2.7 22.5 -- -- 249 10.0 8.8 -- -- -- -- -- -- -- -- -- -- -- 4.9 22 -- -- 248 10.1 8.8 -- -- -- -- -- -- -- -- -- -- -- 6.6 22 -- -- 248 9.6 8.7 -- -- -- -- -- -- -- -- -- -- -- 8.8 21 -- 10 246 8.2 7.9 -- -- -- -- -- -- -- -- -- -- -- 

12.5 20.5 2.6 10 248 2.8 7.1 .01 <.01 .92 <.02 .09 4.9 23 6.6 9.6 8.4 23 

Lake Osceola South (site number 283556081204101)

1.1 22.5 2.0 10 214 10.8 9.0 .01 .01 .80 <.02 .08 5.1 25 4.4 10.0 2.7 19 7.8 21.5 -- -- 213 9.9 8.9 -- -- -- -- -- -- -- -- -- -- -- 

10.1 20.5 -- -- 213 8.7 8.2 -- -- -- -- -- -- -- -- -- -- -- 13 20 -- -- 213 4.2 7.2 -- -- -- -- -- -- -- -- -- -- -- 19 19.5 1.3 10 221 0.2 6.8 .09 <.01 .84 <.02 .09 4.1 24 4.4 10.0 2.7 19 
Water Quality 37

Table 8. Water-quality variations with sampling depth in the Winter Park chain of lakes, June 11, 1992[°C, degrees Celsius; μS/cm; microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; SU, Standard Units; <, less than]

Site

identification

number

Sampling

depth

(feet)

Temperature,

water

(°C)

Specific

conductance 

(μS/cm)

Oxygen,

dissolved

(mg/L)

pH,

whole water,

field

(SU)

Nitrogen,ammonia

total

(mg/L as N)

Nitrogen,

nitrite

total

(mg/L as N)

Nitrogen,

ammonia+ 

organic, 

total 

(mg/L as N)

N

N

(m

Lake Virginia

283517081204001 1.0 30.5 211 8.4 8.8 0.02 <0.01 1.4 

7.8 30.0 208 5.4 7.8 .02 <.01 1.4 

15.6 23.5 235 .1 7.5 .99 <.01 2.0 

Lake Virginia West

283518081210201 1.0 30.5 211 8.2 8.2 .02 <.01 1.3 

8.0 28.0 208 2.0 7.3 .02 <.01 1.3 

16.0 24.0 265 .1 7.4 1.1 <.01 2.6 

Lake Mizell

283534081201801 1.0 30.5 260 7.9 9.0 .02 <.01 1.4 

5.9 30.5 261 6.0 7.7 .01 <.01 1.4 

12.1 25.0 273 .2 7.2 .28 <.01 1.3 

Lake Mizell North

283545081201901 1.0 30.5 256 7.6 8.7 .01 <.01 1.5 

6.0 30.0 254 5.8 7.3 .01 <.01 1.5 

11.8 25.0 322 .6 7.2 1.3 <.01 4.0 

Lake Osceola South

283556081204101 1.0 30.0 215 7.6 6.9 .04 <.01 1.3 

11 25.5 225 .1 6.9 .21 <.01 1.5 

22.0 21.0 291 .1 7.1 2.5 <.01 4.0 

Lake Osceola North

283615081202801 1.0 30.5 215 7.7 7.4 .15 <.01 1.6 

9.9 26.5 207 .1 7.0 .02 <.01 1.4 

20.0 22.0 259 .1 6.6 2.3 <.01 3.3 

Lake Maitland South

283644081204901 1.0 30.5 216 8.5 9.2 .02 <.01 1.2 

10.3 27.0 210 1.4 7.2 .02 <.01 1.1 20.6 23.0 285 .2 7.1 1.5 <.01 3.2 

Lake Maitland West

283708081214201 .9 30.5 209 8.2 8.9 .02 <.01 .97 

7.0 28.5 209 5.6 7.5 .02 <.01 1.0 

14.3 26.5 259 3.7 7.2 .19 <.01 1.1 

Lake Maitland North

283709081210401 1.0 31.0 208 8.8 9.2 .02 <.01 1.0 

9.1 29.0 209 5.3 8.2 .02 <.01 .96 

18.5 26.0 285 .1 7.2 .83 <.01 2.0 
38 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Figure 19. Median chlorophyll-a concentrations for the Winter Park lakes and stage of Lake Virginia, 1989-92.

0

5

10

15

20

25

30

35 

0

5

10

15

20

25

30

35 

5

10

15

20

25

30

35 

0

5

10

15

20

25

30

35 

CHLOROPHYLL CONCENTRATION, IN MICROGRAMS PER LITER -a

ON D J F MAM J J A S ON D J FM AM J J A SON D J F MAM J J A S

1989 1990 1991 1992

ON D J F MAM J J A S ON D J FM AM J J A SON D J F MAM J J A S

1989 1990 1991 1992

ON D J F MAM J J A S ON D J FM AM J J A SON D J F MAM J J A S

1989 1990 1991 1992

ON D J F MAM J J A S ON D J FM AM J J A SON D J F MAM J J A S

1989 1990 1991 1992

LAKE MAITLAND

LAKE OSCEOLA

LAKE MIZELL

LAKE VIRGINIA

64

68

65

66

67

LAKE STAGE, IN FEET

ABOVE SEA LEVEL

ON D J F MAM J J A S ON D J FM AM J J A SON D J F MAM J J A S

1989 1990 1991 1992

LAKE VIRGINIA 
Water Quality 39

The Florida Department of Environmental 

Protection assesses the quality of surface waters of the 

State at 2-year intervals. This assessment is submitted to 

the U.S. Environmental Protection Agency in accordance with the Federal Clean Water Act (Florida 

Department of Environmental Protection, 1994). The 

lakes are assessed using a trophic state index (TSI) that 

is based on the classification system developed by Carlson (1977). The TSI defines lake quality in terms of 

chlorophyll-a, total nitrogen, and total phosphorus concentrations, and Secchi-disk transparency. Lake-water 

quality is classified according to TSI values, with values 

in the range of 0 to 59 considered indicative of good 

water quality, 60 to 69 considered fair, and 70 or greater 

considered poor. Using median values for these measurements of water quality for the Winter Park lakes 

during the 3-year sampling period results in the TSI values listed below. All of the TSI values are indicative of 

good water quality, except for Secchi-disk transparency, 

which falls within the fair category.

Correlation Analysis

A rank correlation analysis was done to determine the relation of lake water quality to short and 

long-term runoff. Rank correlation analysis uses the 

relative rank of the water-quality characteristic in 

relation to all samples, rather than the concentration or 

Chlorophyll-a

(μg/L)

Secchidisk

transparency

(in.)

Total 

nitrogen

(mg/L)

Total 

phosphorus

(mg/L)

Median value, 

all lakes

12 40 0.84 0.03

TSI 53 60 53 45

value. For example, the lowest value for each characteristic is assigned a rank of 1, and the highest value is 

Lake

Water

temperature

Specific 

conductancepH Calcium Magnesium Sodium Potassium

Alkalinity Chloride Sulfate Chlorophyll-a

Coefficient of rank correlation with lake stage

Virginia 0.55 -- -- -- -- -- -0.56 -0.55 -0.52 -0.71 --

Mizell .50 -.74 -- -.69 -- -.65 -- -- -- -- 0.53

Osceola .50 -.55 -- -- -.57 -.62 -.53 -- -- -.62 .77

Maitland -- -.54 .51 -- -.57 -.59 -- -- -- -- --

replaced with the number of samples in the data set 

(17 for most water-quality characteristics). This use of 

ranks eliminates effects from the type of data distribution (normal or not normal). The correlation of water 

quality with the total rainfall for a period of 2 weeks 

before the sample date was selected as a measure of 

short-term runoff effects. The use of a 2-week period 

is arbitrary and other periods might show a different 

correlation to lake water quality. Lake stage was 

selected as an indicator of long-term runoff quantities 

because the total volume of water in the lakes is a 

function of runoff quantities for a relatively long (but 

unspecified) period of time.

Non-zero coefficients of correlation indicate 

that there is a relation between the parameters being 

compared. The probability that a coefficient of correlation was significantly different from zero was determined and the correlation was considered to be 

significant if there was less than a 5 percent chance 

that the coefficient of correlation could actually be 

zero (the coefficients were significant at the 5-percent 

level). A positive coefficient of correlation indicates a 

direct relation between the variables being tested; a 

negative coefficient indicates an inverse relation. 

None of the water-quality characteristics were 

related to 2-week antecedent rainfall at a 5-percent 

significance level, indicating that short-term runoff 

does not significantly affect lake water quality. However, several characteristics, listed in the table below, 

were related to lake stage at a 5-percent significance 

level, indicating a correlation to long-term runoff. The 

coefficients of rank correlation are listed only if they 

are significant at the 5-percent level.

The rank-correlation analysis indicates that 

specific conductance and some major-dissolved 

constituent concentrations tend to be lower at 

higher lake stages (negative coefficient of rank correlation). This is an indication of the dilution effects 

caused by rainfall and storm runoff on lake water. 
40 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Figure 20a. Selected water-quality constituents for Lake Maitland, 1967-92.

1965 1975 1980 1985 1990 1995 1970

1965 1975 1980 1985 1990 1995 1970

1965 1975 1980 1985 1990 1995 1970

1965 1975 1980 1985 1990 1995 1970

TOTAL PHOSPHORUS 

CONCENTRATION,

IN MILLIGRAMS PER LITER TOTAL NITROGEN CONCENTRATION,

IN MILLIGRAMS PER LITER

SECCHI DISK DEPTH

IN INCHES

0

200

50

100

150

0

40

10

20

30

0

0.10

0.02

0.04

0.06

0.08

0

4

1

2

3

CHLOROPHYLLa

CONCENTRATION, IN

MICROGRAMS PER LITER

U.S. Geological Survey

Other sources 

EXPLANATION

SOURCE OF DATA
Water Quality 41

Figure 20b. Selected water-quality constituents for Lake Virginia, 1967-92.

0

300

100

200

0

60

20

40

0

0.6

0.2

0.4

0

2

1

1965 1970 1975 1985 1980 1990 1995

1965 1970 1975 1985 1980 1990 1995

1965 1970 1975 1985 1980 1990 1995

1965 1970 1975 1985 1980 1990 1995

TOTAL PHOSPHORUS 

CONCENTRATION,

IN MILLIGRAMS PER LITER

TOTAL NITROGEN

CONCENTRATION,

IN MILLIGRAMS PER LITER

SECCHI DISK DEPTH

IN INCHES

U.S. Geological Survey

Other sources 

EXPLANATION

SOURCE OF DATA

CHLOROPHYLLa

CONCENTRATION, IN

MICROGRAMS PER LITER
42 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Figure 20c. Selected water-quality constituents for Lake Osceola, 1980-92.

0

60

60

80

80

20

20

40

40

0

2

1

3

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

TOTAL PHOSPHORUS 

CONCENTRATION,

IN MILLIGRAMS PER LITER

TOTAL NITROGEN

CONCENTRATION,

IN MILLIGRAMS PER LITER

SECCHI DISK DEPTH

IN INCHES

U.S. Geological Survey

Other sources 

EXPLANATION

SOURCE OF DATA

0

100

0

0.02

0.04

0.06

0.08

CHLOROPHYLLa

CONCENTRATION, IN

MICROGRAMS PER LITER
Water Quality 43

Figure 20d. Selected water-quality constituents for Lake Mizell, 1980-92.

0

60

20

40

0

2.0

0.5

1.0

1.5

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

TOTAL PHOSPHORUS 

CONCENTRATION,

IN MILLIGRAMS PER LITER

TOTAL NITROGEN

CONCENTRATION,

IN MILLIGRAMS PER LITER

SECCHI DISK DEPTH

IN INCHES

U.S. Geological Survey

Other sources 

EXPLANATION

SOURCE OF DATA

0

200

50

100

150

0

0.02

0.04

0.06

0.08

CHLOROPHYLLa

CONCENTRATION, IN 

MICROGRAMS PER LITER
44 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

There is a positive rank correlation between chlorophyll-a concentration and lake stage in Lakes Mizell 

and Osceola. This could indicate that the cumulative 

effect caused by nutrients washed into the lakes stimulates algae growth and causes a higher chlorophyll-a

concentration. However, the positive relation between 

chlorophyll-a and lake stage may be indirect and may 

be the result of a common seasonality effect. That is, 

the higher lake stages tend to occur during warmer 

months when algae growth is more pronounced. This 

possibility is supported by the relation between water 

temperature and lake stage in all but one lake. The 

positive correlation between water temperature and 

lake stage indicates that higher lake stages occur 

during warmer periods (the summer rainy season).

Stormwater

All of the storm drains in the city of Winter Park 

are equipped with plastic screen to prevent leaf and 

other stormwater-borne debris from entering the lakes. 

At least 68 storm drains empty into the Winter Park 

chain of lakes (fig. 3). Stormwater quality was sampled at sites 9 and 11 (fig. 6), both on storm drains 

discharging into Lake Osceola. The sites were selected 

because of the convenience in measuring discharge 

and installing and operating the automatic sampling 

equipment. They also were typical of stormwater 

discharge at other locations in the chain of lakes in 

terms of size and adjacent land use. All samples of 

stormwater were discharge-weighted composites for 

individual storms.

Method of Sampling

Storm discharge and accumulated stormwater 

volume for each storm were estimated at sites 9 and 11 

from measurements of stage above a V-notch weir, 

made at 1-min intervals using a micrologger. The 

weirs were installed in the storm drains at an elevation 

that was higher than the maximum lake elevation. 

Discharge was computed from a stage-discharge 

relation derived from the theoretical sharp-crested 

weir function (Brater and King, 1976) for the weir and 

for the culvert walls, when stage exceeded the depth of 

the weir notch. The micrologger activated a sampler 

each time accumulated stormwater discharge reached 

a selected volume. The sampler then pumped a 

selected volume of water from the storm sewer into a 

40-L vessel. The pumped volume and the accumulated 

stormwater volume were selected to provide an 

adequate volume of water for laboratory analysis from 

storms producing about 0.2 in. to 2.0 in. of rain. 

Because the lake level occasionally exceeded 

the elevation of the mouth of the storm drain at site 11, 

the part of the drain where the sampler intake was 

located sometimes contained lake water. To avoid 

sampling before the lake water was flushed from the 

storm drain by stormwater, specific conductance of the 

water present at the sampler intake was monitored by 

the micrologger at 1-min intervals. The sampling 

event was not begun until the specific conductance of 

the water had fallen to less than 100 μS/cm, indicating 

that most of the lake water had been flushed from the 

system. The specific conductance of the lake water 

generally was greater than 200 μS/cm.

The composite samples of stormwater were 

removed from the sampler within a few hours of the 

end of the storm and chilled to 4 °C. Samples were 

analyzed for total nitrogen, total phosphorus, 

suspended solids, and specific conductance. For 

selected storms, additional samples were analyzed for 

dissolved nitrogen and phosphorus, and for screenable 

nitrogen, phosphorus, and solids. The samples for 

dissolved nitrogen and phosphorus were filtered 

through a 0.45-micron membrane filter. The samples 

for screenable material were prepared by passing a 

well-mixed aliquot of the sample though the plastic 

screening material used in construction of the stormwater-debris traps. The screened water was then analyzed for total nitrogen, total phosphorus, and 

suspended solids.

Chemical Characteristics

Water-quality analyses of composite samples 

from site 9 for 17 storms are given in table 9, and 

table 10 gives the results for composite samples from 

site 11 for 16 storms. Box plots of total nitrogen and 

phosphorus in unfiltered stormwater are given in 

figure 21.

Nitrogen and phosphorus concentrations were 

of comparable magnitude at the two stormwater sites. 

The median total nitrogen concentration was 

2.23 mg/L at site 9 and 3.06 mg/L at site 11 (tables 9 

and 10, fig. 21). The median total phosphorus concentration was 0.40 mg/L at site 11 and 0.34 mg/L at 

site 9. The relatively small differences in concentrations between these two sites is an indication that the 

data collected at these two sites is transferrable to 

other locations around the lakes. 
Water Quality 45

Comparison of the screened and filtered samples indicates that most of the suspended solids, nitrogen, and 

phosphorus in stormwater is carried by particles 

smaller than the debris-trap screen-pore size (about 

25 μm) and larger than the filter-pore size (0.45 μm), 

as summarized in the following table. This indicates 

that the debris traps are not very effective in reducing 

Figure 21. Total nitrogen and phosphorus concentrations in unfiltered stormwater at 

two sites near Lake Osceola (site numbers are from fig. 6). TOTAL PHOSPHORUS CONCENTRATION, IN MILLIGRAMS PER LITER TOTAL NITROGEN CONCENTRATION, IN MILLIGRAMS PER LITER Site 9 Site 11

Number of samples

Maximum

Median

90th percentile

75th percentile

25th percentile

10th percentile

Minimum

EXPLANATION

16

16

16

17

17

6

5 

4

3

2

1

1

0 

0 

0.2

0.4 

0.6

0.8

Site

Total nitrogen Total phosphorus Suspended solids

Percent

remaining

after

screening

Percent

remaining

after

filtering

Percent

remaining

after

screening

Percent

remaining

after

filtering

Percent remaining

after

screening

9 93 32 89 31 78

11 84 33 93 41 79

nutrients in stormwater. Screening the stormwaterthrough debris-trap screening material removed only 

about 7 to 16 percent of the total nitrogen and about 7 to 

11 percent of the total phosphorus. A filtering system 

that could remove particles as small as 0.45 μm would 

still allow 30 to 40 percent of the nitrogen and phosphorus loads to enter the lakes as dissolved constituents.
46 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Table 9. Water-quality characteristics of stormwater at site 9 (Webster Drive) near Lake Osceola

[All concentrations are in milligrams per liter. Specific conductance is given in microsiemens per centimer at 25 °C. in, inches; rw, raw water; sw, screened 

water; fw, filtered water; --, no sample taken]

Date

Storm 

rainfall, 

(in. )

Total 

nitrogen

(rw)

Total 

nitrogen

(sw)

Total 

nitrogen

(fw)

Total 

phosphorus, 

(rw)

Total 

phosphorus, 

(sw)

Total 

phosphorus, 

(fw)

Suspended 

solids,

(rw)

Suspended 

solids, 

(sw)

Specific 

conductance

91-03-31 0.72 2.79 2.64 0.96 0.60 0.58 0.32 -- -- 102

91-04-06 2.34 2.03 1.68 .32 .34 .29 .09 121 63 63

91-04-07 .69 1.30 1.10 .47 .25 .23 .11 36 31 65

91-04-17 1.07 2.24 2.23 .67 .38 .35 .14 72 60 83

91-04-23 2.30 2.17 2.00 .64 .40 .40 .11 133 83 53

91-05-01 .55 1.85 1.88 .42 .21 .21 .07 83 35 61

91-05-19 1.01 2.66 2.26 .59 .40 .38 .14 100 84 60

91-05-21 .07 1.74 -- -- .28 -- -- 77 -- 65

91-06-02 .06 2.36 -- -- .26 -- -- 60 -- 105

91-06-06 .65 1.20 1.07 .45 .19 .18 .07 39 32 66

91-06-25 .38 2.23 -- 1.16 .30 -- .15 44 -- 78

91-07-27 .53 2.67 -- -- .28 -- -- 66 -- 85

91-08-18 .19 3.29 -- -- .46 -- -- 147 -- 102

91-08-24 .47 1.65 1.52 .83 .24 .23 .12 74 53 65

92-02-05 1.61 2.01 1.71 .84 .35 .31 .14 78 64 57

92-05-27 .99 4.01 -- -- .53 -- -- 112 -- 140

92-06-02 .38 4.13 4.12 1.61 .51 .45 .08 108 86 120

Median 2.23 1.88 .66 .34 .31 .12 78 62 66

Mediana

a

For dates when rw, sw, and fw determinations were made.

2.03 1.88 0.64 0.35 0.31 .11 80 62 --

The actual effectiveness of the stormwaterscreening process cannot be determined precisely from 

these data because the automatic samplers that collect 

the water samples for analysis restrict the size and 

total volume of debris. Thus, the data are biased 

toward debris small enough to be pumped through the 

3/8-in. diameter sampling tubing. However, an estimate of the effectiveness of debris removal can be 

made by calculating the nutrient loads removed, based 

on the volume of debris collected and on the nutrient 

content of the debris. 

Quantities of debris removed from storm-drain 

screens are measured in units of 30-gal containers by 

the city of Winter Park. To convert this volumetric 

measure to a mass of phosphorus and nitrogen, the 

dry-mass-to-volume ratio and the nutrient content of 

the debris was determined. The dry-mass-to-volume 

ratio was estimated by collecting the debris from 

8 traps after a storm in February 1992. Most of the 

debris were oak-tree leaves, but some twigs and grass 

also were present. A volumetric measure of the debris 

was made using a 2-gal bucket, and the dry weight of 

the debris was obtained by first air-drying, then weighing, the material. The dry-mass-to-volume ratios of the 

debris ranged from 0.39 to 1.02 lb/gal, and averaged 

0.71 lb/gal.

Three different estimates of the nutrient content 

of the debris were made. The estimates differ substantially in technique, and represent different possible 

interactions between the debris and the lakes. The 

estimates provide a better understanding of the 

possible range of the nutrient content of debris available to the lakes.

One estimate of the nutrient content of debris 

was derived from analysis of live plant material 

reported by the University of Florida (Morris and 

Pritchett, 1982). Trunk, branch, and foliage samples of 

trees, including two species of oak trees that grow near 

the Winter Park lakes, were analyzed for several 

constituents, including total nitrogen and phosphorus. 
Water Quality 47

Table 10. Water-quality characteristics of stormwater at site 11 (Elizabeth Drive) near Lake Osceola

[All concentrations are in milligrams per liter. Specific conductance is given in microsiemens per centimer at 25 °C. in, inches; rw, raw water; sw, screened 

water; fw, filtered water; --, no sample taken]

Date

Storm 

rainfall, 

(in. )

Total 

nitrogen

(rw)

Total 

nitrogen

(sw)

Total 

nitrogen

(fw)

Total 

phosphorus, 

(rw)

Total 

phosphorus, 

(sw)

Total 

phosphorus, 

(fw)

Suspended 

solids,

(rw)

Suspended 

solids, 

(sw)

Specific 

conductance

91-06-07 .27 2.08 1.88 0.37 0.25 0.23 0.04 61 50 69

91-06-19 .47 3.02 2.36 .94 .27 .26 .10 8 44 88

91-06-25 .38 2.99 -- 1.35 .40 -- .13 60 -- 92

91-06-26 1.76 2.27 1.78 .16 .42 .47 .10 92 79 47

91-07-20 2.33 1.46 1.36 .56 .31 .28 .09 61 45 40

91-07-28 .84 1.68 1.69 .94 .21 .20 <.01 32 28 55

91-08-13 .24 3.10 -- -- .32 -- -- 45 -- 80

91-08-18 .19 2.56 -- -- .35 -- -- 67 -- 80

91-08-24 .47 1.60 1.59 .83 .27 .24 .13 30 38 80

92-01-14 .48 3.82 3.53 1.69 .71 .69 .29 94 90 124

92-01-23 .15 3.09 -- -- .42 -- -- 80 -- 92

92-02-23 .94 3.50 2.79 .60 .73 .67 .22 96 82 80

92-03-25 .97 5.17 -- -- .86 -- -- 162 -- 90

92-05-14 .79 4.10 -- -- .48 -- -- 52 -- 98

92-05-27 .99 3.78 -- -- .60 -- -- 188 -- 80

92-06-02 .38 3.42 -- -- .40 -- -- 40 -- --

Median 3.06 1.83 .83 .40 .27 .13 61 48 80

Mediana

a

For dates when rw, sw, and fw determinations were made.

2.18 1.83 0.72 0.29 0.27 0.12 61 48 --

The percent of the dry mass of nitrogen and phosphorus in the leaves is given below:

Another estimate of the nutrient concentration of 

the debris was made by collecting some dry, dead 

debris--mostly fallen oak-tree leaves--from the street 

near one of the debris traps. Leaves from the land 

surface were selected rather than leaves from the traps 

because of the possibility that nitrogen and phosphorus 

could have been leached from the mostly submerged 

debris in the traps before removal. The leaves were 

rinsed with distilled water to remove surface dirt, placed 

in a blender, and pulverized. The material was then 

digested and ten sample splits were analyzed for total 

ammonia-plus-organic nitrogen and total phosphorus 

using analytical methods for bottom material (Fishman 

and Friedman, 1989). The percent of total dry mass 

ranged from 0.057 to 0.084 for nitrogen, with a mean of 

0.066 percent. For phosphorus, the range was 0.021 to 

0.026 percent and the mean was 0.023 percent. 

A third estimate of the nutrient content of debris 

was made by placing dead, fallen leaf debris collected 

from streets into water from the lakes and determining 

the amount of nutrients leached. This was done by placing 30-g samples of debris (mostly oak leaves) in 4-L 

containers that were filled with water from Lake Virginia and capped, leaving no air space. One container 

was sampled almost immediately (within 45 min) and 

the others were stored in the absence of light at room 

temperature (22-25 °C). At selected time intervals, a 

container was opened and a 250 mL aliquot of water 

was removed for analysis of total nitrogen and phosphorus content. Results are given below:

Species

Nitrogen, in 

percent of 

dry mass

Phosphorus, 

in percent of 

dry mass

Quercus latifolia 1.34 0.066

Quercus nigra 1.39 0.060
48 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

These data indicate that some nitrogen and 

phosphorus are leached from the leaves almost immediately and that additional nitrogen and phosphorus 

are leached after 3 days and after 10 days, respectively. 

Although the amounts of nitrogen and phosphorus 

leached after 10 days may not represent the total 

amounts available through complete digestion of the 

leaves, comparison of the leaching data with that from 

the previous analyses of leaf debris indicates similar 

amounts of material: 0.06 percent nitrogen leached 

after 10 days compared with a mean nitrogen content 

of 0.066 percent in digested samples, and 0.03 percent 

phosphorus leached compared with 0.023 in the 

digested samples.

To estimate the amount of nutrients removed by 

the debris traps, the data for nutrient contents derived 

from the third method mentioned were used. The 

rounded values of 0.06 percent nitrogen and 

0.03 percent phosphorus were used to make the 

following estimates of total mass removal for calender 

years 1989-91:

These data indicate that, although the debris 

traps are useful for removing large organic debris and 

nonbiodegradable material, the mass of nutrients 

removed from stormwater is very small.

Ground Water

Although there are uncertainties in the calculations of the amount of ground-water inflow, ground 

water probably makes up, on average, about 15 percent 

of the total inflow to the lakes (table 5). Therefore, the 

Leaching time,

days

Nitrogen,

concentration,

mg/L

Nitrogen, 

leached,

mg/kg

Nitrogen, 

leached,

in percent of 

dry mass

Phosphorus, concentration,

mg/L

Phosphorus, 

leached,

mg/kg

Phosphorus, 

leached,

in percent

of dry mass

0.02 0.86 120 0.012 0.09 10 0.001

3 2.8 370 .037 1.9 250 .025

10 4.8 640 .064 2.5 330 .033

 10 (duplicate) 4.5 600 .060 2.2 290 .029

Year

Amount of 

debris 

removed 

(gallons)

Estimated

dry mass

(pounds)

Estimated 

phosphorus mass

(pounds)

Estimated

nitrogen 

mass 

(pounds)

1989 1,560 1,100 -- --

1990 2,580 1,800 -- --

1991 6,700 4,800 -- --

Mean 3,610 2,600 1.56 0.78

quality of the ground water can have a significant 

impact on the quality of water in the lakes. Twenty samples of surficial ground water were collected from the 

periphery of the lakes in February-June 1992. The locations of sites sampled are shown in figure 11 and the 

analyses of the samples are given in table 11.

The quality of the surficial ground water was 

highly variable. The specific conductance ranged from 

about 200 to 740 μS/cm. The water was generally 

acidic, probably because of organic matter in the surficial sediments. The pH ranged from 4.6 to 7. Calcium 

concentrations ranged from less than 10 to 140 mg/L 

and sulfate from less than 1 to 130 mg/L.

The variation of surficial ground-water quality 

can be seen by comparing diagrams of major ion concentrations (figs. 22-25). The diagrams, which are 

grouped by lake, do not show any obvious changes 

from lake to lake. The ground-water samples collected 

from around Lake Maitland (fig. 22), show slightly 

less variation than the other lakes, but this could be the 

result of random variations, rather than an actual 

difference in ground-water quality between lakes.

The most unusual samples came from sites 4, 8 

and 11 (one each from near Lakes Virginia, Mizell, 

and Osceola, respectively). Those samples all had 

relatively high specific conductance, calcium, and 

alkalinity. The influence of water from the Upper 

Floridan aquifer at those sites is unlikely because the 

vertical hydraulic gradient is downward and Upper 

Floridan irrigation water probably is not used at the 

sites. A possible explanation is that cement debris 

might have been used as fill along the shoreline near 

the sampling sites, although this was not obvious when 

the samples were collected.

Nitrogen and phosphorus concentrations in the 

surficial ground water also varied over a wide range. 

Comparing the sums of total ammonia and organic 

nitrogen, nitrate, and nitrite, the highest value occurred 

at site 5 (15.39 mg/L) and the lowest (less than 

0.21 mg/L) at sites 17 and 18. Total orthophosphorus 

ranged from 0.08 mg/L at sites 8 and 20 to less than 

0.01 mg/L at sites 1, 2, 10, 13, 14, 15, 17, and 19. 
W

aterQuality49

Table 11. Surficial ground-water quality in the vicinity of the Winter Park chain of lakes[°C degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum -cobalt units; μS/cm, microsiemens per centimeter at 25 °C; Wh, whole water; SU, standa μg/L, micrograms per liter; --not analyzed; <, less than]

Site

 identification

 number

Date Map 

no.

Temperature, 

water 

(°C)

Turbidity

(NTU)

Color

(Pt-Co

units)

Specific

 conductance

(μS/cm)

pH, 

Wh,

field (SU)

Nitrogen,ammonia 

total

(mg/L as N)

Nitrogen, 

nitrite 

total 

(mg/L 

as N)

Nitrogen, ammonia,+ 

organic 

total 

(mg/L 

as N)

Nitrogen,

NO2

+NO3

total

(mg/L as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total

(mg/L 

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium, 

dissolved 

(mg/L 

as Ca)

Magnesium,

 dissolved 

(mg/L as 

Mg)

Sodium,

 dissolved 

(mg/L) 

as Na)

Potassium, 

dissolved 

(mg/L as K).

Chloride, 

dissolved 

(mg/L as Cl)

283503081203701 05-04-92 1 -- <1.0 <5 210 4.6 0.010 <0.010 0.36 4.60 0.040 <0.010 0.3 12.0 3.8 10.0 4.1 32 283506081202201 05-20-92 2 25.0 4.6 35 710 6.2 ..030 <.010 .30 .040 .020 <.010 3.4 56 34 16 30 68 283523081202701 05-20-92 3 24.0 <1.0 35 200 6.0 4.20 .020 5.0 <.020 .120 .040 5.7 20 3.4 7.0 4.0 10.0 283525081210001 05-04-92 4 26.0 3.9 <5 400 7.0 .080 <.010 .38 .070 .140 .050 1.3 81 1.5 4.8 .70 4.6 283527081201001 06-10-92 5 23.0 2.2 5 475 4.9 .020 <.010 .39 15.0 .030 .010 2.0 52 12 4.8 24 18 283537081202401 06-10-92 6 25.0 <1.0 30 275 6.0 2.20 .010 2.8 <.020 .050 .060 8.5 30 9.4 4.5 7.0

10.0

283537081204101 02-21-92 7 21.5 -- -- 250 -- .100 <.010 .27 <.020 .020 .010 -- 26 8.6 3.5 .80 36 283547081202201 06-10-92 8 26.0 29 30 740 6.4 .980 <.01 1.7 <.020 .110 .080 16 140 7.2 11 2.5 30 283549081203201 05-05-92 9 24.0 <1.0 15 210 6.3 .090 <.010 .46 .040 .090 .070 5.2 21 3.6 10.0 4.3 20 283600081205001 05-06-92 10 -- <1.0 <5 275 6.2 <.010 <.010 <.20 .020 .030 <.010 1.2 31 6.1 10.0 3.5 24 283610081204501 02-21-92 11 20.0 -- -- 550 -- .120 .010 .64 .140 .100 .020 -- 96 5.7 13 3.5

28

283617081200902 05-05-92 12 24.0 <1.0 <5 225 5.5 .040 <.010 .31 <.020 .050 .020 5.6 14 6.1 14 3.4 29 283625081203501 05-07-92 13 22.0 1.1 35 200 5.4 .030 <.010 1.0 <.020 .040 <.010 13 22 5.4 6.8 .60 20 283630081205401 05-07-92 14 20.0 1.9 <5 245 5.8 <.010 <.010 .38 3.60 .060 <.010 .6 21 5.8 8.0 4.1 28 283641081202901 06-11-92 15 25.5 62 10 373 4.8 .02 <.010 .26 7.6 .600 <.01 .9 23 14 17 5.1 36 

283642081211101 05-06-92 16 26.0 1.8 10 470 6.1 .100 .010 .55 <.020 .110 .060 6.0 63 6.7 15 5.7

43

283647081212301 05-07-92 17 20.0 <1.0 <5 240 4.8 <.010 <.010 <.20 .030 .040 <.010 .2 15 6.5 12 1.7 33 283702081203701 05-07-92 18 23.0 3.6 5 215 4.9 <.010 <.010 <.20 .400 .110 .050 0.7 9.6 4.8 16 3.2 26 283713081214701 05-21-92 19 24.5 14 50 250 4.7 .560 .010 .81 <.020 .080 <.010 2.1 9.8 6.3 14 9.9 34 283723081210201 05-07-92 20 22.0 1.9 60 210 5.4 .540 <.010 1.1 <.020 .070 .080 13 15 4.0 11 5.1 29 
50 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

0

0 .5 1 KILOMETER

.5 1 MILE

20

18

19

17

16

14

15

19SURFICIAL-AQUIFER DATA

COLLECTION SITE AND

NUMBER FROM TABLE 4

N

Figure 22. Major ion concentrations in water from the surficial aquifer near Lake Maitland 

(site numbers are from fig. 11).
Water Quality 51

Figure 23. Major ion concentrations in water from the surficial aquifer near Lake Virginia (site 

numbers are from fig. 11).

0

0 .5 1 KILOMETER

.5 1 MILE

4 SURFICIAL-AQUIFER DATA

COLLECTION SITE AND

NUMBER FROM TABLE 4

7

4

1

2

3

0 

Milliequivalents per liter 

5 4 4 3 3 2 2 11 5

Sodium + Potassium Chloride + Fluoride

CATIONS ANIONS

Magnesium

Calcium

Sulfate

Bicarbonate + Carbonate

EXPLANATION 

N
52 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

Figure 24. Major ion concentrations in water from the surficial aquifer near Lake Osceola (site 

numbers are from fig. 11).

0

0 .5 1 KILOMETER

.5 1 MILE

12

13

11

10

9

N

9 SURFICIAL-AQUIFER DATA

COLLECTION SITE AND

NUMBER FROM TABLE 4
Water Quality 53

0

0 .5 1 KILOMETER

.5 1 MILE

8

6

5

N

8 SURFICIAL-AQUIFER DATA

COLLECTION SITE AND

NUMBER FROM TABLE 4

Figure 25. Major ion concentrations in water from the surficial aquifer near Lake Mizell (site numbers are 

from fig. 11).
54 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

The nutrient concentrations in surficial ground water 

apparently were not related to the proximity to property with a septic tank (fig. 11). The highest nitrogen 

and phosphorus concentrations occurred at sites that 

do not have septic tanks. This indicates that fertilizer 

applications probably are the primary source of nutrients in the surficial ground water. The highest nitrogen 

concentration was at a site near an orange grove.

The surficial ground water also was analyzed 

for boron and molybdenum because those elements do 

not naturally occur in ground water in Florida. Boron 

and molybdenum are trace elements added to fertilizer. 

Borax (which contains boron) is an ingredient of laundry soap and thus could indicate the effects of outflow 

from septic tanks. The results of analyses for molybdenum were not conclusive. The highest concentration of 

boron, 200 μg/L, was at site 2, and the second highest 

concentration was 120 μg/L at site 5. Neither site is 

near a septic tank. The boron at those sites probably is 

the result of fertilizer application to nearby land. For 

comparison, the boron concentration in treated wastewater in southwest Orange County was 190 μg/L 

(L.A. Bradner, U.S. Geological Survey, oral commun., 

1993).

ANALYSIS OF NUTRIENT LOADING

Simple steady-state input-output models can be 

used to predict the trophic status of a lake and nutrient 

concentrations as functions of inflow loading. 

Commonly used models of this type include the 

Vollenweider model (1968), and the Dillon-Rigler 

model (1974). These models were originally developed using data for lakes in more temperate parts of 

North America, and the applicability of the models to 

subtropical lakes (such as in Florida) has been questioned. Baker and others (1981) have extensively 

investigated the use of simple input-output models and 

have developed modifications that improve the applicability of the models to Florida lakes. These models 

have been formulated in terms of both total nitrogen 

and total phosphorus. In order to apply steady-state 

input/output models, the flow and nutrient budgets for 

the lakes must be calculated. Flow budgets were 

discussed in a previous section. This section describes 

the development of nutrient budgets and their application to a steady-state loading model.

Constituent Budgets

The discharge and water-quality data for the 

Winter Park chain of lakes were combined to calculate 

chloride and nutrient budgets for the lakes. Budgets 

were calculated for the chemically conservative 

(nonreactive) constituent chloride to estimate the 

validity of the hydrologic budgets.

The concentrations of chloride, nitrogen, and 

phosphorus for surface inflow and outflow used in the 

calculations were the medians of all the samples 

collected at the respective sites during the study 

(table 6). Ground-water inflow concentrations were 

the medians of the 20 samples collected (table 11). The 

concentrations used for ground-water outflow were 

medians of the water samples collected near the lake 

bottoms (tables 7 and 8). The concentrations used for 

the change in lake-storage terms were derived from 

the medians of all samples collected in all the lakes. 

The data for chloride concentration in rainfall are from 

Lake Hope in Maitland (Irwin and Kirkland, 1980, 

p. 63)(fig. 1). Data for atmospheric deposition of 

nitrogen and phosphorus are from Baker and others 

(1981), who estimated deposition rates for urban areas 

in Florida. The chloride concentration for stormflow 

(7 mg/L) was from data collected at Lakes Faith, 

Hope, and Charity by German (1983) (fig. 1).

Net loads were calculated for water years 1990-92 

(table 12 and fig. 26). Water year 1990 was a dryer-thanaverage year, 1991 was wetter-than-average, and 1992 

was about average. Because chloride is a conservative 

constituent, the difference between inflow and outflow 

of chloride is an indication of the accuracy of the constituent budgets. These differences, with respect to inflow 

loads, ranged from 3 percent in 1992 to 18 percent in 

1991. The differences probably are because of a combination of uncertainties in the water budget and in chemical characterization of the inflow waters.

The percent of the total loads contributed by each 

source of inflow for water year 1992 is different for 

each of the three constituents studied. For example, 

ground water probably contributed 47 percent of the 

total chloride load to the lakes, but only about 20 percent of the nitrogen and 15 percent of the phosphorus. 

Rainfall contributes 3 percent of the chloride, 19 percent of the nitrogen, and 15 percent of the phosphorus. 

Stormflow, in contrast, contributes 4 percent of the 

chloride, 24 percent of the nitrogen, and 44 percent of 

the phosphorus. Surface inflow contributes 45 percent 

of the chloride, 37 percent of the nitrogen, and 

26 percent of the phosphorus. 
Water Quality 55

Table 12. Estimated chloride and nutrient budgets for the Winter Park chain of lakes, water years 1990-1992

[Chloride concentration data for rainfall and stormflow are from German, 1983. Nitrogen and phosphorus loads were computed from areal loading rates 

from Baker and others (1981), and are 0.76 grams per square meter per year for nitrogen and 0.05 grams per square meter for phosphorus. Lake area used to 

calculate loads is 4.5 x 107

 ft2. in/yr, inch per year; mg/L, milligrams per liter; tons/yr, tons per year; --, no contribution or not applicable]

Flow

(in/yr)

Chloride

concentration

(mg/L)

Total nitrogen

concentration

(mg/L)

Total 

phosphorous

concentration

(mg/L)

Chloride 

load

(tons/yr)

Nitrogen 

load

(tons/yr)

Phosphorus 

load

(tons/yr)

1990 Inflow:

Rainfall 38 1.6 -- -- 7.1 3.5 0.23

Stormflow 4 7 2.6 .37 3.3 1.2 0.17

Surface inflow 56 16 .9 .05 104.7 5.9 0.33

Estimated ground-water inflow 0 28 .8 .05 0 0 0

Total 98 115.1 10.6 0.73

1990 Outflow:

Evaporation 51 -- -- -- -- -- --

Surface outflow 20 18 .85 .05 42.0 2.0 0.12

Estimated ground-water outflow 33 21 2.0 .07 81.0 7.7 0.27

Lake storage change -6 19 .84 .04 -13.3 -0.7 -0.03

Total 98 109.7 9.0 0.36

Net change: +5.4 +1.6 +0.37

1991 Inflow:

Rainfall 58 1.6 -- -- 11.0 3.5 0.23

Stormflow 32 7 2.6 .37 26.2 9.7 1.38

Surface inflow 73 16 .9 .05 136.4 7.7 0.43

Estimated ground-water inflow 28 28 .8 .05 91.6 2.6 0.16

Total 191 265.2 23.5 2.20

1991 Outflow:

Evaporation 48 -- -- -- -- -- --

Surface outflow 103 18 .85 .05 216.6 10.2 0.60

Estimated ground-water outflow 33 21 2.0 .07 81.0 7.7 0.27

Lake storage change 7 19 .84 .04 16.0 0.6 0.02

Total 191 313.6 18.5 0.89

Net change: -48.4 +5.0 +1.31

1992 Inflow:

Rainfall 48 1.6 -- -- 9.0 3.5 0.23

Stormflow 15 7 2.6 .37 12.3 4.6 0.66

Surface inflow 67 16 .9 .05 125.2 7.0 0.39

Estimated ground-water inflow 40 28 .8 .05 130.8 3.7 0.23

Total 170 277.3 18.8 1.51

1992 Outflow:

Evapotranspiration 47 -- -- -- -- -- --

Surface outflow 90 18 .85 .05 189.2 9.0 0.53

Estimated ground-water outflow 33 21 2.0 .07 81.0 7.7 0.27

Lake storage change 0 19 .84 .04 -- -- --

Total 170 270.2 16.7 0.80

Net change: +7.1 2.1 +0.71
56 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

The most variable source of nitrogen and phosphorus loading to the lakes is stormwater (table 12 and 

fig. 26). The total 1990 annual rainfall was only 38 in. 

and stormwater contributed about 12 percent of the 

nitrogen and 23 percent of the phosphorus to the lakes, 

less than the amount contributed by bulk precipitation 

or tributary inflow. The total annual rainfall was 59 in. 

Figure 26. Total nitrogen, phosphorus, and dissolved chloride loads to 

the Winter Park lakes, 1990-92.

300

0

50

100

150

200

250

2.5

0

0.5

1.0

1.5

2.0

25

0

5

10

15

20

SOURCE

rain

storm runoff

tributary inflow

ground-water inflow

LOAD TO LAKES, IN TONS PER YEAR

TOTAL NITROGEN

TOTAL PHOSPHORUS

DISSOLVED CHLORIDE

1990 1991 1992

1990 1991 1992

1990 1991 1992

in 1991 and stormwater contributed about 63 percent 

of the phosphorus load and 41 percent of the nitrogen 

load, more than any other inflow component.

Errors in the estimates of various flow-budget 

components can result in errors in the constituent-load 

budgets. To determine the effect of such errors, a 
Water Quality 57

sensitivity analysis was made using the data for water 

year 1992, a year of about average rainfall and no 

change in lake storage. The estimated values for 

several components of the flow budget were varied to 

determine the effect on the constituent-load budget. As 

part of the sensitivity analysis, ground-water inflow 

and stormwater inflow were increased but not 

decreased, because the estimates used in the flow 

budgets were thought to be minimum values. 

Although several components were evaluated in the 

analysis, only ground-water inflow and stormwater 

inflow had any significant effect on the constituentload budget. Increasing the ground-water inflow rate 

by 50 percent resulted in an increase in the groundwater component of the chloride load of 10 percent 

(from 47 to 57 percent); however, the nitrogen load 

increased only 7 percent (from 20 to 27 percent) and 

the phosphorus load increased only 8 percent (from 16 

to 22 percent). Increasing stormwater inflow by 

25 percent resulted in an increase in the chloride load 

from 4 to 6 percent, in the nitrogen load from 24 to 

29 percent, and in the phosphorus load from 43 to 

50 percent. Increasing or decreasing both surface 

inflows and outflows by 10 percent had little effect on 

the load budgets, changing the loads of all components 

by only 1 to 2 percent. 

Modified Dillon-Rigler Model

Baker and others (1981) reported that the best 

model for predicting nitrogen and phosphorus concentrations for lakes where input and output can be 

measured was a modification of the Dillon-Rigler 

model. This model requires the determination of a 

retention coefficient and is not applicable to lakes for 

which a flow and nutrient budget has not been 

determined. The flow and nutrient budget can be 

estimated for the Winter Park chain of lakes, so the 

Dillon-Rigler model was selected for predicting the 

response of the lakes to changes in nutrient-inflow 

loading.

Generally, the quantity of either total nitrogen or 

of total phosphorus in lake water is more important 

than the other in controlling the rate of algal growth in 

lakes. In the majority of temperate-zone lakes, 

phosphorus is the limiting nutrient (Baker and others, 

1981). However, nitrogen may be the more common 

limiting nutrient in Florida. Algal bioassays of 

31 lakes in Florida, part of the National Eutrophication 

Survey by the U.S. Environmental Protection Agency 

during the early 1970’s, indicated that 74 percent of the 

31 lakes were nitrogen limited (U.S. Environmental 

Protection Agency, 1977). In the absence of algal 

bioassays, ratios of total-soluble-inorganic-nitrogen to 

total-soluble-reactive-phosphate (SIN:SRP) indicate 

which nutrient (nitrogen or phosphorus) is limiting. 

SIN:SRP ratios of less than 10:1 indicate nitrogen 

limitation and ratios greater than 20:1 indicate phosphorus limitation.

No algal bioassays were made for the Winter 

Park lakes, but the low ratios of nitrogen to phosphorus indicate that the lakes probably are nitrogen 

limited. Using median concentrations for all water 

samples for the lakes, the ratios of ammonia-plusnitrate-plus-nitrite nitrogen to orthophosphate ranged 

from 0.5 to 1.0. Although this low nitrogen-to-phosphorus ratio can indicate that nitrogen control is more 

important than phosphorus control, the response of 

lake productivity to nutrient input is so complex that 

control of both nitrogen and phosphorus input probably is desirable, and analysis of both nitrogen and 

phosphorus input-output models is discussed in this 

section.

The Dillon-Rigler equation which has been used 

for simulating nitrogen or phosphorus concentration in 

Florida lakes is (Baker and others, 1981):

C = A1[L(1-R)/Qs]

A2 (3)

where

C is predicted constituent concentration, 

in milligrams per liter;

L is constituent input load to the lakes, in 

grams per square meter per year;

 R is retention coefficient (dimensionless);

Qs is hydraulic loading rate, or the sum of

all input volumes to 

lakes divided by total lake area, in

meters per year;

A1 and A2 are empirical coefficients used to

optimize the agreement between 

predicted and actual in-lake concentrations (Baker and others,1981)

The retention coefficient, Rn for nitrogen or Rp

for phosphorus, is defined by:

R = 1 - Pout/Pin (4)
58 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

where

Pout is the amount of nitrogen or phosphorus 

leaving the lake (mass), and

Pin is the amount of nitrogen or phosphorus 

entering the lake (mass).

No attempt was made to find the values for A1

and A2 that give the best agreement between simulated 

and actual concentration. Rather, the equation was 

used in its basic form (A1 and A2 equal to 1) to simulate total nitrogen and total phosphorus concentrations 

in the Winter Park lakes, as a function of input 

loading. A comparison of the actual and simulated inlake total nitrogen and total phosphorus concentrations 

for the entire lake system as a unit is given below. In 

these simulations, the retention coefficients were 

determined for each year and the simulated nitrogen 

and phosphorus concentrations were computed using 

the constituent input load and the hydraulic loading for 

the year. For convenience, hydraulic loading rates 

were converted to feet per year. 

The simulated and actual total nitrogen and total 

phosphorus concentrations in lake water generally are 

in close agreement. The largest discrepancy between 

simulated and actual concentrations is for total nitrogen in 1992. The reason for this relatively large 

discrepancy may be related to the seasonality of 

nitrogen concentrations (fig. 18). Total nitrogen concentrations tend to peak in spring and early summer, 

and in 1992 two sets of samples were taken during this 

peak. No further samples were taken that year, so the 

median of the nitrogen concentrations for water year 

1992 may be higher than a seasonally-representative 

median. 

The values for Rn and Rp can vary in relation to 

the relative contribution for the various sources of 

nutrients. For example, nitrogen and phosphorus in 

storm runoff resulting from large particles (such as 

leaf fragments) might be deposited on the lake bottom, 

buried, and thus removed from further reaction in the 

lakes; however, nutrients transported into the lake in 

dissolved or fine-particulate form would not be 

removed by settling and burial. Thus, R could be 

higher during years with more stormwater inflow.

The possibility that R varies according to the 

amount of storm runoff seems to be indicated by estimates of Rn and Rp for each of the 3 years of study 

(fig. 27). The Rn ranged from 0.07 in 1990 to 0.24 in 

1991. A similar pattern occurred for Rp: the Rp for 

both 1990 and 1992 was about 0.47 while the Rp for 

1991 was 0.60. The hydraulic loading rate for the 

lakes was 8.2 ft (98 in.) in 1990; 16.0 ft (192 in.) in 

1991; and 14.2 ft (170 in.) in 1992. Of these totals, the 

stormwater input to the lakes in 1990 was 4 in.; 1992, 

15 in.; 1991, 32 in. These data indicate that Rn and Rp

can vary with the amount of stormwater inflow to the 

lakes, but might be relatively constant below a threshold stormwater input of 15 in.

The Rn values calculated for the Winter Park 

lakes are in the lower range of values computed for 

other Florida lakes (fig. 27). This could indicate that 

the Winter Park lakes are more effective in fixing 

nitrogen than other lakes, or it could indicate an error 

in the nitrogen budget. However, the Rn values are not 

extremely low compared to other Florida lakes. The 

Rp values calculated for the Winter Park lakes are 

within the range of those calculated for other lakes 

with similar hydraulic loading (fig. 27). This general 

similarity of Rn and Rp values for the Winter Park 

chain of lakes to those estimated for other lakes 

suggests that estimates of nutrient inputs to the Winter 

Park lakes are not widely in error. This supports the 

use of the modified Dillon-Rigler model for predicting 

changes in lake nutrient concentrations in response to 

changes in inflow nutrient loading. 

Potential Effects of Stormwater Treatment

Reduction of nutrients in stormwater inflow to 

the lakes probably would be the most practical method 

for improving or maintaining lake water quality 

because the other sources of nutrients are more diffuse 

and generally contain lower concentrations. The 

Dillon-Rigler model was used to predict steady-state 

lake nitrogen and phosphorus concentration as a function of percent nutrient removal in stormwater. In 

judging the significance of lake nutrient-concentration 

reductions, the criteria of Baker and others (1981) for 

Florida lakes are used: lakes are considered to be in a 

mesotrophic state (moderately enriched) if nitrogen 

Year

Total nitrogen, 

median for all lakes

(mg/L)

Total phosphorus, median 

for all lakes

(mg/L)

Actual Model Actual Model

1990 0.88 0.85 0.04 0.03

1991 0.83 0.80 0.03 0.04

1992 1.10 0.84 0.03 0.04
Water Quality 59

Figure 27. Nitrogen and phosphorus retention coefficients in Florida lakes (Data for other Florida lakes are from U.S. 

Environmental Protection Agency, 1977).

-0.2

1.0

0.2

0.4

0.6

0.8

RETENTION COEFFICIENT, Rp

0 20 40 60 80 100 120 140 160 180 200 220 240

HYDRAULIC LOADING, IN FEET PER YEAR

Winter Park lakes

Other Florida lakes

-2.0

1.5

-1.5

-1.0

-0.5

0

0.5

1.0

RETENTION COEFFICIENT, R n

0 20 40 60 80 100 120 140 160 180 200

Winter Park lakes

Other Florida lakes

TOTAL NITROGEN

TOTAL PHOSPHORUS

0

220 240

1991

1992

1990

1991

1992 1990
60 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

concentrations are 0.5 mg/L or higher, or phosphorus 

concentrations are 0.025 mg/L or higher; and the lakes 

are considered to be in a eutrophic state (highly 

enriched) if the nitrogen concentrations are 1.0 mg/L 

or higher, or phosphorus concentrations are 0.05 mg/L 

or higher. Because the 3 study years represented a 

wide range in precipitation and storm runoff, predicted 

effects of stormwater treatment were made for each 

year using the retention coefficients determined for 

that year. 

It should be emphasized that input-output models, such as the Dillon-Rigler model used in this study, 

are relatively simple representations of lake systems 

and apply only to steady-state conditions. Also, there 

is some degree of uncertainly in quantity and quality 

of ground-water inflow and quantity of ground-water 

outflow. Therefore, the following simulations of nutrient concentrations should not be regarded as being 

exact, but rather as estimates intended to determine the 

usefulness of treating stormwater inflow to the lakes. 

Yearly time periods may not represent steady-state 

conditions, so the simulations should be regarded as 

representative of steady-state periods of varying 

amounts of runoff in assessing possible effects of 

stormwater treatment. Thus, 1990 should be viewed as 

representative of periods with low rainfall, 1991 as 

representative of periods of high rainfall, and 1992 as 

representative of periods of average rainfall. The 

actual time period needed to approximate steady-state 

conditions may be several years, so the simulations 

made for 1990, 1991, and 1992 should not be interpreted as representing effects of stormwater treatment 

that would occur within 1 year.

 Stormwater inflow to the lakes was only 4 in. 

during 1990, or about 4 percent of the total inflow of 

98 in. Because of the small quantity of stormwater 

inflow, predicted treatment effects are relatively small 

(fig. 28). The steady-state lake nitrogen and phosphorus concentrations with no stormwater treatment are 

predicted to be 0.85 and 0.034 mg/L, respectively, and 

with full treatment (all nitrogen and phosphorus 

removed from stormwater) the predicted lake 

concentrations are 0.75 mg/L (nitrogen) and 

0.026 mg/L (phosphorus). Thus, even with the complete removal of nitrogen and phosphorus from stormwater, the lakes still would be in a mesotrophic state 

with respect to both nutrients because of the nutrient 

input from rainfall, ground-water seepage, and surface 

inflow.

Stormwater inflow to the lakes in 1991 was 

32 in., or about 17 percent of the total inflow of 192 in. 

Stormwater inflow transported more than half of the 

phosphorus and about 41 percent of the nitrogen to the 

lakes and contributed more nitrogen and phosphorus 

than any other source. Without treatment, the predicted steady-state nitrogen and phosphorus concentrations are 0.80 and 0.039 mg/L, respectively. With 

complete nutrient removal from the stormwater 

inflow, the predicted steady-state lake nitrogen and 

phosphorus concentrations drop to 0.47 and .015 

mg/L, respectively, below the mesotrophic level. 

Though complete nutrient removal is impractical, the 

model shows that reductions of nutrient levels in 

stormwater inflow could be beneficial to the lakes.

When the model was applied to data from 1992, 

a year with near-normal rainfall, results indicated that 

removal of nitrogen and phosphorus from stormwater 

inflow would lower lake nitrogen concentrations by 

about 0.2 mg/L and lake phosphorus concentrations by 

about 0.017 mg/L. Other inputs of nutrients would still 

cause the lakes to be in a mesotrophic state with 

respect to nitrogen but not phosphorus.

These modeling results indicate that reduction 

in nutrient content of stormwater inflow could benefit 

the lakes through lower lake phosphorus and nitrogen 

concentrations, except during periods with belownormal rainfall when other sources of nutrients are 

more important. However, except during high-rainfall 

periods, even complete removal of nutrients from 

stormwater could not lower lake concentrations of 

total nitrogen to levels below those considered to be 

mesotrophic.

Possible effects of uncertainties in estimates of 

inflow-outflow quantities on simulated nutrient concentrations were investigated by a sensitivity analysis. 

In this analysis, the same sets of inflow-outflow data 

used to assess the sensitivity of the constituent budgets 

to flow quantities were used. Data for 1992 were used 

because that year had about average rainfall and no 

change in lake storage.

The highest estimates of total nitrogen and phosphorus in lake water, with no removal of nitrogen or 

phosphorus from stormwater, are for the case where the 

estimate of stormwater inflow was increased by 

25 percent and ground-water inflow was reduced by 

the amount of the added stormwater (fig. 29). The lowest estimates of total nitrogen and phosphorus were for 

the case where ground-water inflow was increased by 

100 percent, with ground-water outflow increased by 
Water Quality 61

0

0.05

0.01

0.02

0.03

0.04

SIMULATED TOTAL PHOSPHORUS CONCENTRATI

ON, IN MILLI

GRAMS PER LITER

0 10 20 30 40 50 60 70 80 90 100

PERCENT CONSTITUENT REMOVAL IN STORM WATER INFLOW

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

SIMULATED TOTAL NITROGEN CONCENTRATI

ON, IN MILLI

GRAMS PER LITER

0 10 20 30 40 50 60 70 80 90 100

Minimum mesotropic level

Minimum mesotropic level

WATER YEAR

1990

1991

1992

WATER YEAR

1990

1991

1992

Figure 28. Simulated steady-state nitrogen and phosphorus concentrations as a function of percent removal in 

stormwater inflow.
62 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

0

0.05

0.01

0.02

0.03

0.04

SIMULATED TOTAL PHOSPHORUS CONCENTRATION, IN MILLI

GRAMS PER LITER SIMULATED TOTAL NITROGEN CONCENTRATI

ON, IN MILLI

GRAMS PER LITER

0 10 20 30 40 50 60 70 80 90 100

PRECENT CONSTITUENT REMOVAL IN STORMWATER INFLOW

Ground water inflow increased by 50%, balanced by ground water outflow

Ground water inflow increased by 50%, balanced by ground water outflow

Ground water inflow increased by 100 percent, balanced by ground water outflow

Ground water inflow increased by 100 percent, balanced by ground water outflow

Ground water inflow increased by 100 percent, balanced by surface outflow

Ground water inflow increased by 100 percent, balanced by surface outflow

Stormwater inflow increased by 25 percent, balanced by ground water inflow

Stormwater inflow increased by 25 percent, balanced by ground water inflow

Stream inflow and outflow both decreased by 10 percent, balanced by ground water inflow

Stream inflow and outflow both decreased by 10 percent, balanced by ground water inflow

Stream inflow and outflow increased by 10 percent, balanced by ground water inflow

Stream inflow and outflow increased by 10 percent, balanced by ground water inflow

0

1.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 10 20 30 40 50 60 70 80 90 100

Minimum mesotropic level

Minimum mesotropic level

Figure 29. Sensitivity of simulated lake concentrations of total nitrogen and total phosphorus to changes in 

quantities of ground-water inflow and outflow, stream inflow and outflow, and stormwater inflow.
Summary and Conclusions 63

the same amount. The difference in simulated N and P 

(no removal of N or P from storm water) for these two 

extremes is only about 0.05 mg/L total nitrogen and 

0.007 mg/L total phosphorus. With complete removal 

of nitrogen and phosphorus in storm water, the difference between the two extremes is even smaller. Therefore, the sensitivity analysis does not indicate that 

large errors in simulated concentrations of N and P 

could result from uncertainty in the flow budget.

SUMMARY AND CONCLUSIONS

The Winter Park chain of lakes (Lakes Maitland, 

Virginia, Osceola, and Mizell) have a combined area 

of about 900 acres and an immediate drainage area of 

about 3,100 acres. The lakes are an important recreational resource for the surrounding communities, but 

there is concern about the possible effects from stormwater runoff and nutrient-enriched ground-water seepage on the quality of water in the lakes.

Color fathometer surveys were used to compile 

bathymetric maps of the lakes. Mean depths range 

from about 11 to 15 feet and maximum depths range 

from about 30 feet in Lake Maitland to 21 feet in Lake 

Mizell. Three features that may be sinkholes were 

noted in Lake Maitland. If the hydraulic connection to 

the underlying Upper Floridan aquifer through such 

features is good, downward leakage of water through 

the lake bottom could be significant. Based on 

14 samples of bottom sediments collected in Lakes 

Maitland and Virginia, the bottom material is predominately fine to medium sand (in the range of 0.1 to 

1.0 millimeter). 

Because the type and amount of vegetation in 

the littoral part of lakes can be important to the 

processes that affect eutrophication, a survey of littoral 

vegetation was made in March 1992. The most 

common species of emergent vegetation in terms of 

percent of total vegetated area include torpedo grass, 

cattail, and elephant ear. Plant similarity indices for 

the four lakes indicate little difference in terms of 

species present. Nuisance vegetation did not seem to 

be a problem in the lakes.

The lakes receive water from several sources: 

rainfall on lake surfaces, inflow from other surfacewater bodies, stormflow that enters the lakes through 

storm drains or by direct runoff from land adjacent to 

the lakes, and from ground-water seepage. Rainfall, 

surface-inflow, and lake-stage data were collected 

from October 1, 1989, to September 30, 1992, so that 

flow budgets could be calculated for the lakes. Stormflow and ground-water seepage, more difficult to 

measure, were estimated for the 3 years of the study by 

evaluating stage hydrographs.

Water leaves the lakes by evaporation, by 

surface outflow, and by ground-water outflow. Of the 

three, only surface outflow can be measured directly. 

Lake evaporation was estimated to be 80 percent of 

pan evaporation. Ground-water outflow was calculated by analyzing lake stage recessions during dry 

periods. The results were consistent with estimates 

based on the head difference between the lakes and the 

underlying Upper Floridan aquifer, and the estimated 

thickness of sediments separating the two. The estimated ground-water outflow rate also is consistent 

with vertical leakage rates derived from ground-water 

flow modeling.

Flow budgets were calculated for the 3 years of 

the study. In water year 1992 (a year with about average rainfall), inflow consisted of rainfall, 48 inches 

(in.); stormflow, 15 in.; surface inflow, 67 in.; and 

ground water, 40 in. The calculated outflows were 

evaporation, 47 in.; surface outflow, 90 in.; ground 

water, 33 in.

In addition to flow data, water-quality data were 

used to calculate nutrient budgets for the lakes. 

Bimonthly water samples were collected for 3 years at 

sites in the lakes and at surface-inflow and -outflow 

sites, and were analyzed for physical characteristics, 

dissolved oxygen, pH, specific conductance, major 

ions, nutrients, and chlorophyll. Specific conductance 

ranged from about 190 to 230 microsiemens per centimeter in Lakes Maitland, Virginia, and Osceola and 

from about 226 to 260 microsiemens per centimeter in 

Lake Mizell. The difference probably is because Lake 

Mizell is smaller and somewhat isolated from the flow 

system of the other lakes. The median concentrations 

of total ammonia-plus-organic nitrogen in all the lakes 

ranged from 0.79 to 0.99 milligrams per liter (mg/L). 

Median total phosphorus concentrations range from 

less than 0.02 to 0.20 mg/L. Samples collected from 

near the bottom of Lakes Virginia and Osceola had 

lower temperature and dissolved oxygen and higher 

specific conductance and ammonia concentrations 

than the depth-integrated samples.

The water quality in the Winter Park lakes generally is fair to good, based on a trophic-state index 

used by the Florida Department of Environmental 

Protection for assessing the tropic state of Florida 

lakes. This index was determined from median total 
64 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes Central Florida, 1989-92

nitrogen, total phosphorus, and chlorophyll-a concentrations, and median Secchi-disk transparency for all 

lakes for the period September 1989 to June 1992.

Stormwater samples were collected for 

17 storms at one site and 16 storms at another stormdrain site on Lake Osceola. Median total nitrogen 

concentrations were 2.23 and 3.06 mg/L and median 

total phosphorus concentrations at the sites were 0.40 

and 0.34 mg/L. Experiments with leaf litter indicate 

that debris traps around storm drains undoubtedly 

reduce the volume of large debris entering the lakes. 

However, the traps do little to reduce the loads of 

nutrients entering the lakes because dissolved loads 

contribute the largest part of the total nutrient concentrations.

Based on a one-time sampling of 20 sites around 

the lakes, surficial ground-water quality is highly 

variable. Nutrient concentrations also were highly 

variable and could not be correlated to the proximity 

of septic tanks. Fertilizer probably is the major source 

of nutrients in the surficial ground water. 

Nutrient budgets were calculated for the lakes 

for the 3 years of the study. The most variable source 

of nutrient loading to the lakes is stormwater. Models 

of nutrient loading were also calculated for the lakes 

using the Dillon-Rigler (1974) equation as modified 

by Baker and others (1981). These models indicate 

that the Winter Park chain of lakes are in the lower 

range of retention values for nitrogen compared to 

other Florida lakes and about average for phosphorus. 

The modeling indicates that reduction of nutrients in 

stormflow would probably improve lake-water 

quality; however, even with complete removal of 

nitrogen and phosphorus from stormwater, the lakes 

might still be mesotrophic during periods of belowaverage rainfall because of the input from the other 

sources of inflow to the lakes.

Selected References

Baker, L.A., Brezonik, P.L. and Kratzer, C.R., 1981, 

Nutrient loading-trophic state relationships in Florida 

lakes: Florida Water Resources Research Center 

Publication no. 56, 126 p.

Brater, E.F., and King, H.W., 1976, Handbook of hydraulics 

for the solution of hydraulic engineering problems 

(6th ed.): McGraw-Hill, 584 p.

Brenner, Mark, Binford, M.W. and Deevey, E.S., 1991, 

part III, Lakes, chap. 11, Freshwater wetlands and 

aquatic ecosystems, in Myers, R.L. and Ewel, J.J., eds., 

Ecosystems of Florida: Orlando, University of Central 

Florida Press, p. 364-391.

Canfield, D.E. Jr., 1983, Prediction of chlorophyll-a

concentrations in Florida lakes: The importance of 

phosphorus and nitrogen: Water Resources Bulletin, 

v. 19, no. 2, p. 255-262.

Canfield, D.E., Jr., and Hoyer, M.V., 1987, The nutrient 

assimilation capacity of the Little Wekiva River: 

University of Florida Institute of Food and 

Agricultural Sciences, Gainesville, 268 p.

Carlson, R.E., 1977, A trophic state index for lakes: 

Limnology and Oceanography, v. 22, p. 3661-369.

Davis, S.N. and DeWiest, R.J.M., 1966, Hydrogeology: 

New York, John Wiley, 463 p.

Dillon, P.J. and Rigler, F.H., 1974, A test of a simple 

nutrient budget model predicting the phosphorus 

content of lake waters: Journal of Fishery Resources 

Board, Canada, v. 31 p. 1771-1778.

Engstrom, D.R. and Brezonik, P. L., 1989, Evaluation of 

sediment accumulation rates in Lakes Virginia and 

Maitland in the Winter Park chain of lakes, Winter 

Park, Florida: Report submitted to Prefessional 

Egineering Consultants, Inc. for the City of Winter 

Park, 22 p. 

Fishman, M.J. and Friedman, L.C., eds., 1989, Methods for 

determination of inorganic substances in water and 

fluvial sediments (3rd ed.): U.S. Geological Survey 

Techniques of Water-Resources Investigations, book 5, 

chap. A1, 545 p.

Florida Department of Environmental Regulation, 1983, 

Water-quality standards, in Florida Administrative 

Code: Tallahassee, chap. 17-3.

Florida Department of Environmental Protection, 1994, 

1994 Water quality assessment for the State of Florida, 

Technical appendix, submitted in accordance with the 

Federal Clean Water Act Section 305(b): Tallahassee, 

87 p.

German, E.R., 1983, Water quality of Lakes Faith, Hope, 

Charity and Lucien, 1971-79 in an area of residential 

development and highway construction at Maitland, 

Florida: U.S. Geological Survey Water-Resources 

Investigations 82-51, 71 p.

———1989, Quantity and quality of stormwater runoff 

recharged to the Floridan aquifer system through two 

drainage wells in the Orlando, Florida area: U. S. 

Geological Survey Water Supply Paper 2344, 51 p.

Glace and Radcliffe, Inc., 1989, Septic tank study, Winter 

Park, Fla.: Prepared for the city of Winter Park, 7 p. 

and apps. A and B. 
Selected References 65

Greeson, P.E., Ehlke, T.A., Irwin, G.A., Lium, B.W., and 

Slack, K.V., eds., 1977, Methods for collection and 

analysis of aquatic biological and microbiological 

samples: U. S. Geological Survey Techniques of 

Water-Resources Investigations, book 5, chap. A4, 

332 p.

Irwin, G.A. and Kirkland, R.T., 1980, Chemical and 

physical characteristics of precipitation at selected 

sites in Florida: U.S. Geological Survey Water 

Resources Investigations 80-81, 70 p.

John, P.H. and Lock, M.A., 1977, The spacial distribution of 

groundwater discharge into the littoral zone of a New 

Zealand lake: Journal of Hydrology, v. 33, no. 3/4, 

p. 391-395.

Kerfoot, W.B., 1984, Darcian flow characteristics 

upgradient of a kettle pond determined by direct 

ground water flow measurement: Ground Water 

Monitoring Review, v. 4, no. 4, Fall 1984, p. 188-192.

Kohler, M.A., 1954, Lake and pan evaporation in water-loss 

investigations: Lake Hefner studies, technical report, 

U. S. Geological Survey Professional Paper 269, 

p. 127-148. 

Krebs, C.J., 1985, Ecology--The experimental analysis of 

distribution and abundance (3d ed.): New York, 

Harper Collins Incorporated, 800 p.

Lake County Water Authority, undated, Our vital wetlands: 

Tavares, Florida, Lake County Water Authority, 28 p.

Lichtler, W.F., Anderson, Warren, and Joyner, B.F., 1968, 

Water Resources of Orange County, Florida: Florida 

Geological Survey, Report of Investigations 50, 150 p.

McBride, M.S. and Pfannkuch, H.O., 1975, The distribution 

of seepage within lake beds: U.S. Geological Survey 

Journal of Research, v. 3, no. 5, p. 505-512.

Morris, L.A., and Pritchett, W.L., 1982, Nutrient storage 

and availability in two managed pine flatwoods forests 

in Impacts of Intensive Forest Management Practices, 

Coleman, S.S., Mace, A.C., and Swindel, B.F., eds., 

University of Florida, Gainesville, FL., p. 17-26.

Munter, J.A. and Anderson, M.P., 1981, The use of groundwater flow models for estimating lake seepage rates: 

Ground Water, v. 19, no. 6, p. 608-616.

National Oceanic and Atmospheric Administration, 1990, 

Climatological data, annual summary for Florida, 

1990, v. 94, no. 13, 16 p.

Phelps, G.G., 1982, Hydrology of Lake Tohopekaliga, 

Osceola County, Florida: U. S. Geological Survey 

Water-Resources Investigations Open-File Report 

81-536, 2 sheets.

Professional Engineering Consultants, Inc., 1987, 

Preliminary evaluation of Winter Park chain of lakes, 

Phase I, 74 p. and app.

Rollins College, 1979, The Lake Virginia report 1976-1979 

research program: Ecological Studies of Central 

Florida Lakes, v. VIII, 98 p.

Ross, J.S., 1979, Water turnover in the Winter Park chain, in

Rollins College, The Lake Virginia report 1976-1979 

research program: Ecological Studies of Central 

Florida Lakes, v. VIII, 98 p.

Small, J.W., Jr., Richard, D.I., and Gregory, Eileen, 1988, 

An assessment of the water quality of the Winter Park 

lake chain: Rollins College Biology Department, 

29 p. and app.

Tarver, D.P., Rodgers, J.A., Mahler, M.J., and Lazor, R.L., 

1978, Aquatic and wetland plants of Florida: 

Tallahassee, Florida Department of Natural resources, 

127 p.

Tibbals, C.H., 1990, Hydrology of the Floridan aquifer 

system in east-central Florida: U.S. Geological Survey 

Professional Paper 1403-E, 98 p.

U.S. Environmental Protection Agency, 1977, National 

Entrophrication Survey Working Papers No. 224, 225, 

and 243-280: Corvallis, Oregon, U.S. EPA.

Vollenweider, R.A., 1968, Scientific fundamentals of the 

eutrophication of lakes and flowing waters with 

particular reference to nitrogen and phosphorus as 

factors in eutrophication: Technical Report 

DAS/CSI/68.27, OECD, Paris, 159 p. (Revised 1971).

Wetzel, R.G., 1975, Limnology: Philadelphia, W.B. 

Saunders Company, 743 p.

White, W.A., 1970, The geomorphology of the Florida 

peninsula: Florida Geological Survey Bulletin 51, 

164 p.

Winter, T.C., 1981, Effects of water-table configuration on 

seepage through lakebeds: Limnology and 

Oceanography, v. 26, no. 5, p. 925-934.

Wood, W.W., 1976, Guidelines for collection and field 

analysis of ground-water samples for selected unstable 

constituents: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 1, chap. D2, 

24 p.

Wunderlin, R.P., 1992, Guide to the vascular plants of 

central Florida: Tampa, University Presses of Florida, 

472 p.
Littoral Vegetation

By Brian Beckage and W. Scott Gain
68 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92
Littoral Vegetation 69

CONTENTS

Introduction ........................................................................................................................................................................... 71

Methods ................................................................................................................................................................................. 72

Results ................................................................................................................................................................................... 73

Discussion.............................................................................................................................................................................. 74

Figures

1. Section across a lake littoral zone, showing typical plant species ......................................................................... 72

2. Frequency of occurrence of emergent plant species .............................................................................................. 78

3. Relative areal coverage of emergent plant species................................................................................................. 79

4. Similarity indices for the Winter Park chain of lakes based on emergent plant species........................................ 80

Tables

1-4. Species of emergent vegetation observed in March 1992, at:

1. Lake Maitland ......................................................................................................................................................... 74

2. Lake Virginia........................................................................................................................................................... 75

3. Lake Osceola........................................................................................................................................................... 76

4. Lake Mizell ............................................................................................................................................................. 77
70 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92
Littoral Vegetation 71

Littoral Vegetation

By Brian Beckage and W. Scott Gain

INTRODUCTION

The littoral zone of a lake is the area in which 

the gradual transition from terrestrial to submerged 

aquatic vegetation occurs. A section across a typical 

lake edge is shown in figure 1. Plant species on the 

landward side include overstory trees such as red 

maple, bald cypress, southern magnolia, and 

chinaberry. Toward the lake, these species give way to 

woody shrubs and small trees such as willow, wax 

myrtle, Brazilian pepper, and water primrose and, 

finally, to patches of cattails, various grasses, rushes, 

and other assorted emergent, herbaceous species. As 

the water deepens at the edge of the littoral zone, 

floating plants--such as the yellow cow lily--and 

submerged aquatic plants--such as tapegrass and 

Illinois pondweed--predominate.

Emergent littoral vegetation is rooted below the 

water surface for at least part of the year, but has aerial 

leaves and reproductive structures. This vegetation is 

highly productive with respect to the synthesis of 

organic material because it is able to utilize the 

resources of two environments: the higher water level 

and nutrient availability of the lake, and the much 

greater availability of atmospheric oxygen and carbon 

dioxide in the terrestrial environment (Wetzel, 1975, 

p. 355). In Florida, littoral vegetation can be 

particularly prolific because of the long growing 

season, intense solar radiation, and relatively shallow 

depths of lakes (Brenner and others, 1991, p. 381).

The vegetation in the littoral zone performs a 

variety of important functions which support other 

facets of the lake ecosystem. Within the lake, this 

vegetation is an important basal component of 

herbivorous and detrivorous food webs and provides a 

substrate for algae and other microfloral components 

of the lake ecosystem, as well as a protective 

environment for the reproduction of much of the lake 

fauna. The littoral zone is particularly important to fish 

reproduction because it provides a foraging ground as 

well as protection from predators. Similarly, the 

emergent vegetation in the littoral zone provides 

shelter and foraging grounds for birds, terrestrial 

mammals, and reptiles. Plants in the littoral zone play 

an important part in nutrient cycling within the lake by 

taking up nutrients from the sediments and releasing 

them into the water column where they can be utilized 

by other organisms. The littoral zone is a major source 

of organic matter into the lake because of the great 

productivity of emergent vegetation, along with the 

large amount of attached algae.

Anthropogenic changes in water quality and 

quantity can have a considerable effect on the diversity 

and abundance of emergent aquatic vegetation. 

Changes in land use in the drainage basin of a lake can 

cause increased lake-water concentrations of nitrogen 

and phosphorous and create conditions under which 

exotic plant species can displace native vegetation. 

The erosion and deposition of sediment associated 

with stormwater runoff into lakes also may be 

important because of the displacement of established 

vegetation associated with bank scouring and filling 

which provides conditions favorable to the 

establishment of invasive, exotic species. 

The extent and character of emergent vegetation 

in a lake also is strongly affected by the variability and 

extremes of water levels in the lake. Many plants in 

the littoral zone can only germinate and become 

established during periods of low water or other 

extreme conditions. Bald cypress is one such example. 

After initial establishment during a period of low 

water, bald cypress are very tolerant of prolonged 

flooding as long as they are not completely 

submerged. Many other plant species cannot replace 

themselves without natural water-level fluctuations, 

resulting in changes in the species composition in the 

littoral zone as senescent plants die. Changes in 

sunlight intensity created by developing forest canopy 

and invasive species can significantly reduce the rate 

of development of other aquatic vegetation in streams. 
72 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92

Canfield and Hoyer (1987, p. 4), showed that shade 

provided by streambank vegetation was a dominant 

factor controlling the location and abundance of 

aquatic plants in the Little Wekiva River in Florida. 

Although this finding was specific to a riparian system, canopy development probably plays a similarly 

important role along lake margins.

Figure 1. Section across a lake littoral zone, showing typical plant species.

BALD CYPRESS

WILLOW

CATTAIL

RED MAPLE

MAIDENCANE

YELLOW

TAPEGRASS COW LILY

WATER

SURFACE

METHODS

A survey of the emergent littoral vegetation in 

Lakes Maitland, Mizell, Osceola, and Virginia was made 

in March 1992 to document the approximate distribution 

and density of dominant emergent plant species in the 

littoral zone of the Winter Park chain of lakes. The results 
Littoral Vegetation 73

of this survey were intended to provide a baseline for 

evaluation of future changes in speciation in aquatic 

habitat in response to basin and lake water management. 

Prior to the field survey, the perimeter of each lake was 

divided into 100 ft sections on aerial photographs using 

topographic and other visible features. These features 

were used in the field to delineate the section boundaries. 

Within each section, the areal coverage of each species 

was estimated by sight. Estimates of the extent of the 

shoreline containing emergent vegetation and the average 

distance this zone extended into the lake were recorded.

Plants generally were identified to species, but in 

some instances only to family, using descriptions by 

Tarver and others (1978). Extremely abundant 

submerged aquatic plants also were noted. In certain 

instances, nomenclature follows that of Wunderlin 

(1992). The data were used to compute relative areal 

coverage and the frequency of occurrence of species in 

each lake. Relative areal coverage represents the 

percentage of the total area of emergent littoral vegetation 

dominated by a particular species. Woody species (trees 

and shrubs) were excluded from relative areal coverage 

values because areal coverage for woody species cannot 

readily be compared with areal coverage for nonwoody 

species. Frequency of occurrence, calculated for all 

species, represents the percentage of sections in each lake 

in which a particular species occurred. 

Results

The relative areal coverage and frequencies of 

occurrence for individual species are given for each lake 

(tables 1-4) and are illustrated in figures 2-3. A species 

list was compiled for each lake and a similarity index, 

comparing the species lists for each of the four lakes, was 

computed (fig. 4).

Lake Maitland, the largest of the four lakes, has an 

area of 470 acres. Forty-four percent of the shoreline area 

(which constitutes less than 1 percent of the total lake 

area) contains emergent vegetation. In Lake Maitland, 

torpedo grass was present in 64 percent of the littoral 

sections, followed by bald cypress in 56 percent of the 

sections. Cattail, duck potato, and pickerelweed 

(Pontederia lanceolata) also were common: all three 

were found in approximately 25 percent of the lake 

sections. In terms of areal coverage, torpedo grass was by 

far the most dominant (44 percent of the vegetated littoral 

area), followed by cattails (27 percent). Other species, 

each covering less than 7 percent of the littoral area, 

individually comprise the remainder of the vegetated 

area. One submerged aquatic, Illinois pondweed, was 

very common, and another submerged aquatic, tapegrass, 

was less common. 

In Lake Virginia, 62 percent of the shoreline was 

vegetated. This vegetated area along the shoreline 

represents about 1 percent of the total lake area of 

224 acres. In Lake Virginia, cattails were found in 

57 percent of the littoral sections, closely followed by 

torpedo grass in 45 percent of the sections. Elephant ear 

was present in 32 percent of the sections, and bald 

cypress, water primrose, yellow cow lily, and willow 

were present in 23, 21, 18, and 16 percent of the sections, 

respectively. In terms of areal coverage, cattails were far 

more abundant than any other species, covering 

54 percent of the vegetated littoral area. Torpedo grass 

was the next most abundant species, covering 12 percent 

of the vegetated area; followed by yellow cow lily and 

maidencane, each covering 8 percent of the area; and 

various other species were the least abundant with 

individual areas covering 5 percent or less of the 

vegetated area.

Lake Osceola has an area of 154 acres. Fortysix percent of the shoreline area (less than 1 percent 

of the total lake area) contained emergent vegetation. 

In Lake Osceola, elephant ear was present in 

49 percent of the littoral sections, closely followed 

by torpedo grass in 44 percent of the sections. Bald 

cypress, pickerelweed, flat sedge, pennywort, and water 

primrose were all relatively frequent, present in 35, 35, 

29, 27, and 26 percent of the sections, respectively. No 

species was clearly dominant in terms of areal coverage. 

Torpedo grass, Panicum species, and yellow cow lily 

were most abundant in area, covering 19, 15, and 

12 percent of the vegetated area around the lake, 

respectively. Five other species (fragrant water lily, 

elephant ear, pennywort, pickerelweed, and cattail) each 

covered more than 5 percent of the total vegetated littoral 

area.

Lake Mizell is the smallest of the four lakes with 

an area of 66 acres. In Lake Mizell, 76 percent of the 

shoreline area (about 2 percent of the total lake area) was 

vegetated. Cattails were most frequent, occurring in 

78 percent of the littoral sections. Elephant ear, duck 

potato, water primrose, bald cypress, and water hemlock 

were the next most frequent, found in 39, 33, 29, 27, and 

25 percent of the sections, respectively. Cattails were 

clearly dominant in areal coverage (82 percent of the 

vegetated littoral area). The next most abundant species 

were water hemlock and elephant ear, covering 5 and 

4 percent of the vegetated area, respectively.
74 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92

DISCUSSION

Many factors such as disturbance of the 

shoreline and its overstory, nutrient enrichment of the 

waters, and erosion and sedimentation, interact with 

natural conditions to determine the species 

composition of a lake. The similarity index (fig. 4) 

which shows the commonality of species found in 

each of the four lakes indicates that the lakes generally 

have 70-80 percent of species in common. This is not 

surprising considering the proximity and connection 

between the four water bodies, as well as the similar 

land use in the drainage basins of the lakes.

However, when frequency and coverage are 

considered, the lakes are less similar. Lake Maitland 

was primarily dominated by torpedo grass, followed 

by cattails, with bald cypress present in over 

50 percent of the lake sections. Lake Virginia was 

dominated by cattails, followed by torpedo grass, with 

bald cypress and water primrose in about 25 percent of 

the sections. Lake Osceola was not clearly dominated 

by any species, but torpedo grass and other Panicum 

species were most prolific, with bald cypress in 

33 percent and water primrose in 25 percent of the 

sections. Interestingly, cattails notably were 

suppressed, while elephant ear was quite frequent. 

Lake Mizell was overwhelmingly dominated by 

cattails, followed by water primrose. Water primrose 

was the most frequent woody species, closely 

followed by bald cypress, both present in 

25-33 percent of the sections. 

Table 1. Species of emergent vegetation observed in March 1992, Lake Maitland

 [Total lake area, 470 acres. a, indicates a woody species; --, not present; absence of common name means species were undifferentiated]

Species

 code

Frequency of

occurrence within

sections (percent)

Relative areal

coverage (percent) Scientific name Common name

ACRU 0.5 a Acer rubrum red maple

ALPH -- -- Alternanthera philoxeroide alligator weed

CAFL -- -- Castalia flava yellow water lily

CAOD 4.5 1.02 Castalia odorata fragrant water lily

CEDE 0.5 0.04 Ceratophyllum demersum coontail/hornwort

CEOC -- a Cephalanthus occidentalis buttonbush

CIME 1.0 0.34 Cicuta mexicana water hemlock

CLJA 1.5 0.09 Cladium jamaicense sawgrass

COES 17.5 2.66 Colocasia esculentum elephant ear

CYOD 16.5 1.67 Cyperus odoratus flat sedge

CYPE 1.0 0.08 Cyperaceae sedge family

EICR 0.5 0.01 Eichhornia crassipes water hyacinth

GRAM 9.0 6.90 Gramineae grass family

HYUM 11.5 2.05 Hydrocotyle umbellata pennywort

IRHE -- -- Iris hexagona praire iris

JUEF -- -- Juncus effusus soft rush

LUOC 13.0 a Ludwigia octovalis water primrose

MAGR -- a Magnolia grandiflora southern magnolia

MEAZ -- a Melia azedarach chinaberry

MUSP 2.0 0.16 Musa species banana

MYCE 5.5 a Myrica cerifera wax myrtle

NUAD 2.5 0.68 Nuphar advena yellow cow lily

PAHE 9.0 4.46 Panicum hemitomon maidencane

PAPU 2.5 0.77 Panicum purpurascens para grass

PARE 64.0 43.53 Panicum repens torpedo grass

PASP 1.0 0.13 Panicum species

POCO 0.5 0.01 Pontederia cordata pickerelweed

POHY -- -- Polygonum hydropiperoides smartweed

POLA 24.0 3.98 Pontederia lanceolata pickerelweed

SALA 26.0 3.10 Sagittaria lancifolia duck potato/arrowhead

SASP 6.5 a Salix species willow

SCCA 6.5 1.52 Scirpus californicus giant bulrush

SCTE -- a Schinus terebinthefolius Brazilian pepper
Littoral Vegetation 75

SCVA 1.0 0.08 Scirpus validus soft-stem bulrush

TADI 55.5 a Taxodium distichum bald cypress

TRFL -- -- Tradescantia fluminensis wandering jew

TYSP 26.0 26.65 Typha species cattail

VISP 0.5 0.06 Viburnum species

Table 2. Species of emergent vegetation observed in March 1992, Lake Virginia

 [Total lake area, 224 acres. a, indicates a woody species; --, not present; absence of common name means species were undifferentiated]

Species

 code

Frequency of

occurrence within

sections (percent)

Relative areal

coverage (percent) Scientific name Common name

ACRU 2.0 a Acer rubrum red maple

ALPH 1.0 0.09 Alternanthera philoxeroide alligator weed

CAFL 1.0 0.26 Castalia flava yellow water lily

CAOD 2.0 0.10 Castalia odorata fragrant water lily

CEDE -- -- Ceratophyllum demersum coontail/hornwort

CEOC -- a Cephalanthus occidentalis buttonbush

CIME 5.0 0.61 Cicuta mexicana water hemlock

CLJA -- -- Cladium jamaicense sawgrass

COES 32.5 5.51 Colocasia esculentum elephant ear

CYOD 4.0 0.92 Cyperus odoratus flat sedge

CYPE 2.0 0.11 Cyperaceae sedge family

EICR 4.0 0.32 Eichhornia crassipes water hyacinth

GRAM -- -- Gramineae grass family

HYUM 10.5 1.56 Hydrocotyle umbellata pennywort

IRHE -- -- Iris hexagona praire iris

JUEF -- -- Juncus effusus soft rush

LUOC 21.0 a Ludwigia octovalis water primrose

MAGR 1.0 a Magnolia grandiflora southern magnolia

MEAZ 1.0 a Melia azedarach chinaberry

MUSP -- -- Musa species banana

MYCE 2.0 a Myrica cerifera wax myrtle

NUAD 17.5 8.13 Nuphar advena yellow cow lily

PAHE 12.5 7.68 Panicum hemitomon maidencane

PAPU 11.5 2.32 Panicum purpurascens para grass

PARE 45.0 11.91 Panicum repens torpedo grass

PASP 12.5 2.76 Panicum species

POCO 1.0 0.03 Pontederia cordata pickerelweed

POHY 1.0 0.03 Polygonum hydropiperoides smartweed

POLA 13.5 2.31 Pontederia lanceolata pickerelweed

SALA 6.0 0.88 Sagittaria lancifolia duck potato/arrowhead

SASP 15.5 a Salix species willow

SCCA 4.0 0.22 Scirpus californicus giant bulrush

SCTE -- a Schinus terebinthefolius Brazilian pepper

SCVA -- -- Scirpus validus soft-stem bulrush

TADI 23.0 a Taxodium distichum bald cypress

TRFL 1.0 0.04 Tradescantia fluminensis wandering jew

TYSP 57.5 54.20 Typha species cattail

VISP -- -- Viburnum species

Table 1. Species of emergent vegetation observed in March 1992, Lake Maitland --Continued

 [Total lake area, 470 acres. a, indicates a woody species; --, not present; absence of common name means species were undifferentiated]

Species

 code

Frequency of

occurrence within

sections (percent)

Relative areal

coverage (percent) Scientific name Common name
76 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92

Table 3. Species of emergent vegetation observed in March 1992, Lake Osceola

 [Total lake area, 154 acres. a, indicates a woody species; --, not present; absence of common name means species were undifferentiated]

Species

 code

Frequency of

occurrence within

sections (percent)

Relative areal

coverage (percent) Scientific name Common name

ACRU 1.0 a Acer rubrum red maple

ALPH -- -- Alternanthera philoxeroide alligator weed

CAFL -- -- Castalia flava yellow water lily

CAOD 10.5 9.29 Castalia odorata fragrant water lily

CEDE -- -- Ceratophyllum demersum coontail/hornwort

CEOC 1.0 a Cephalanthus occidentalis buttonbush

CIME 9.5 1.94 Cicuta mexicana water hemlock

CLJA -- -- Cladium jamaicense sawgrass

COES 49.5 7.64 Colocasia esculentum elephant ear

CYOD 29.5 4.89 Cyperus odoratus flat sedge

CYPE 2.0 0.85 Cyperaceae sedge family

EICR -- -- Eichhornia crassipes water hyacinth

GRAM -- -- Gramineae grass family

HYUM 27.5 5.11 Hydrocotyle umbellata pennywort

IRHE 6.5 0.69 Iris hexagona praire iris

JUEF 1.0 0.08 Juncus effusus soft rush

LUOC 26.5 a Ludwigia octovalis water primrose

MAGR 1.0 a Magnolia grandiflora southern magnolia

MEAZ -- a Melia azedarach chinaberry

MUSP -- -- Musa species banana

MYCE 2.0 a Myrica cerifera wax myrtle

NUAD 20.0 11.72 Nuphar advena yellow cow lily

PAHE 9.5 2.35 Panicum hemitomon maidencane

PAPU 13.5 4.84 Panicum purpurascens para grass

PARE 44.0 18.56 Panicum repens torpedo grass

PASP 21.0 15.17 Panicum species

POCO 1.0 0.09 Pontederia cordata pickerelweed

POHY -- -- Polygonum hydropiperoides smartweed

POLA 34.5 5.97 Pontederia lanceolata pickerelweed

SALA 20.0 2.02 Sagittaria lancifolia duck potato/arrowhead

SASP 9.5 a Salix species willow

SCCA 9.5 2.18 Scirpus californicus giant bulrush

SCTE 1.0 a Schinus terebinthefolius Brazilian pepper

SCVA 4.0 0.89 Scirpus validus soft-stem bulrush

TADI 34.5 a Taxodium distichum bald cypress

TRFL -- -- Tradescantia fluminensis wandering jew

TYSP 10.5 5.70 Typha species cattail

VISP -- -- Viburnum species
Littoral Vegetation 77

Table 4. Species of emergent vegetation observed in March 1992, Lake Mizell

 [Total lake area, 66 acres. a, indicates a woody species; --, not present; absence of common name means species were undifferentiated]

Species

 code

Frequency of

occurrence within 

sections (percent)

Relative areal

coverage (percent) Scientific name Common Name

ACRU -- a Acer rubrum red maple

ALPH -- -- Alternanthera philoxeroide alligator weed

CAFL -- -- Castalia flava yellow water lily

CAOD 6.0 0.91 Castalia odorata fragrant water lily

CEDE -- -- Ceratophyllum demersum coontail/hornwort

CEOC 2.0 a Cephalanthus occidentalis buttonbush

CIME 25.5 4.53 Cicuta mexicana water hemlock

CLJA 4.0 0.10 Cladium jamaicense sawgrass

COES 39.0 4.41 Colocasia esculentum elephant ear

CYOD 6.0 0.23 Cyperus odoratus flat sedge

CYPE 6.0 0.55 Cyperaceae sedge family

EICR -- -- Eichhornia crassipes water hyacinth

GRAM -- -- Gramineae grass family

HYUM 6.0 0.15 Hydrocotyle umbellata pennywort

IRHE -- -- Iris hexagona praire iris

JUEF -- -- Juncus effusus soft rush

LUOC 29.5 a Ludwigia octovalis water primrose

MAGR -- a Magnolia grandiflora southern magnolia

MEAZ -- a Melia azedarach chinaberry

MUSP -- -- Musa species banana

MYCE 10.0 a Myrica cerifera wax myrtle

NUAD 8.0 1.22 Nuphar advena yellow cow lily

PAHE 13.5 1.48 Panicum hemitomon maidencane

PAPU -- -- Panicum purpurascens para grass

PARE 6.0 0.35 Panicum repens torpedo grass

PASP 2.0 0.41 Panicum species

POCO -- -- Pontederia cordata pickerelweed

POHY -- -- Polygonum hydropiperoides smartweed

POLA 10.0 0.92 Pontederia lanceolata pickerelweed

SALA 33.5 2.77 Sagittaria lancifolia duck potato/arrowhead

SASP 17.5 a Salix species willow

SCCA -- -- Scirpus californicus giant bulrush

SCTE 2.0 a Schinus terebinthefolius Brazilian pepper

SCVA -- -- Scirpus validus soft-stem bulrush

TADI 27.5 a Taxodium distichum bald cypress

TRFL -- -- Tradescantia fluminensis wandering jew

TYSP 78.5 81.97 Typha species cattail

VISP -- -- Viburnum species
78 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92

0

100

20406080

PERCENT OF SEGMENTS IN WHICH SPECIE WAS OBSERVED

ACRU

ALPH

CAFL

CAOD

CEDE

CEOC

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

LUOC

MAGR

MEAZ

MUSP

MYCE

NUAD

PAHE

PAPU

PARE

PASP

POCO

POHY

POLA

SALA

SASP

SCCA

SCTE

SCVA

TADI

TRFL

TYSP

VISP

SPECIES CODE

LAKE MAITLAND

0

100

20406080

ALPH

CAFL

CAOD

CEDE

CEOC

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

LUOC

MAGR

MEAZ

MUSP

MYCE

NUAD

PAHE

SPECIES COD

LAKE MIZELL

PERCENT OF SEGMENTS IN WHICH SPECIE WAS OBSERVE

0

100

20406080

PERCENT OF SEGMENTS IN WHICH SPECIE WAS OBSERVED

ACRU

ALPH

CAFL

CAOD

CEDE

CEOC

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

LUOC

MAGR

MEAZ

MUSP

MYCE

NUAD

PAHE

PAPU

PARE

PASP

POCO

POHY

POLA

SALA

SASP

SCCA

SCTE

SCVA

TADI

TRFL

TYSP

VISP

SPECIES CODE

LAKE OSCEOLA

0

100

20406080

PERCENT OF SEGMENTS IN WHICH SPECIE WAS OBSERVED

ACRU

ALPH

CAFL

CAOD

CEDE

CEOC

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

LUOC

MAGR

MEAZ

MUSP

MYCE

NUAD

PAHE

SPECIES CODE

LAKE VIRGINIA

Figure 2. Frequency of occurence of emergent plant species.
Littoral Vegetation 79

0

100

20406080

PERCENT OF TOTAL VEGETATED LITTORAL AREA

ALPH

CAFL

CAOD

CEDE

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

MUSP

NUAD

PAHE

PAPU

PARE

PASP

POCO

POHY

POLA

SALA

SCCA

SCVA

TRFL

TYSP

VISP

SPECIES

LAKE MAITLAND

0

100

20406080

PERCENT OF TOTAL VEGETATED LITTORAL AREA

ALPH

CAFL

CAOD

CEDE

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

MUSP

NUAD

PAHE

PAPU

PARE

PASP

POCO

POHY

POLA

SALA

SCCA

SCVA

TRFL

TYSP

VISP

SPECIES

LAKE OSCEOLA

0

100

20406080

PERCENT OF TOTAL VEGETATED LITTORAL AREA

ALPH

CAFL

CAOD

CEDE

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

MUSP

NUAD

PAHE

SPECIES

LAKE MIZELL

0

100

20406080

PERCENT OF TOTAL VEGETATED LITTORAL AREA

ALPH

CALF

CAOD

CEDE

CIME

CLJA

COES

CYOD

CYPE

EICR

GRAM

HYUM

IRHE

JUEF

MUSP

NUAD

PAHE

SPECIES

LAKE VIRGINIA

Figure 3. Relative areal coverage of emergent plant species.
80 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92

Index of Similarity

Lake Maitland Lake Mizell Lake Osceola Lake Virginia

Lake Maitland 1.00 0.75 0.80 0.79

Lake Mizell 0.75 1.00 0.81 0.71

Lake Osceola 0.80 0.81 1.00 0.80

Lake Virginia 0.79 0.71 0.80 1.00

 Index of similarity = 2C / (A + B)

 Where A is the number of species in Lake A

 B is the number of species in Lake B

 C is the number of species in common between Lake A and Lake B

 The index ranges from 0 to 1 with 1 indicating complete similarity

 and 0 indicating complete dissimilarity.

Figure 4. Similarity indices for the Winter Park chain of lakes based on emergent plant species (based on Krebs, 1985, 

p. 447).
APPENDIXES
82 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92
A

ppendix83

Appendix 1. Water-quality data for Lake Virginia 283517081204001[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Whmicrograms per liter; --, not reported; <, less than].

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conduct

ance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L as 

N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

10-04-89 30.0 1.3. 5 191 -- 8.1 50 0.010 <0.010 0.84 <0.020 <0.020 0.020 5.2 21 3.7 8.6 2.6 12-13-89 17.0 1.7 <5 197 8.4 7.8 53 <0.010 <0.010 0.66 <0.020 0.040 0.010 3.6 23 3.8 9.1 2.6 03-02-90 20.0 0.65 10 201 10.0 8.2 54 <0.010 <0.010 0.55 0.020 0.040 0.010 3.5 23 3.9 9.3 2.5 04-25-90 25.0 0.13 <5 204 8.7 8.8 59 0.020 <0.010 0.52 <0.020 0.040 0.010 4.5 24 4.0 9.5 2.2 06-26-90 30.0 1.8 5 210 -- 8.2 60 0.070 <0.010 1.7 <0.020 0.040 0.020 4.9 25 4.1 10 2.7 09-04-90 30.0 0.58 10 209 6.7 7.7 57 0.030 <0.010 1.1 <0.020 0.030 0.020 5.1 24 4.3 10 2.6 10-24-90 27.5 0.64 10 216 7.0 8.0 60 <0.010 <0.010 0.74 <0.020 0.030 0.020 4.5 24 4.3 11 2.5 12-12-90 18.0 0.82 10 225 9.8 8.2 62 <0.010 <0.010 0.74 <0.020 0.050 0.020 5.0 25 4.4 11 2.8 02-28-91 17.5 1.3 5 231 9.1 8.4 66 0.010 0.010 0.79 0.020 0.020 0.010 4.2 27 4.7 11 2.8 04-30-91 29.5 0.94 10 208 10.4 8. 9 60 <0.010 <0.010 1.4 <0.020 0.050 0.020 4.0 25 4.1 10 2.4 06-25-91 30.5 0.68 5 215 9.5 9.1 53 <0.010 <0.010 1.1 <0.020 0.050 0.010 6.3 23 4.1 10 2.8 08-13-91 33.0 1.7 20 192 7.4 8.5 52 <0.010 <0.010 0.75 <0.020 0.030 0.010 5.7 21 3.6 9.0 2.2 10-29-91 25.5 4.4 15 200 9.0 8.2 53 0.020 0.010 1.0 <0.020 <0.010 <0.010 4.9 22 3.7 9.2 2.7 12-16-91 19.0 3.6 10 200 6.7 7.6 55 0.010 <0.010 0.87 <0.020 0.030 0.020 6.0 22 3.9 9.5 2.8 02-24-92 20.5 1.6 10 200 9.3 8.2 53 0.010 <0.010 0.81 <0.020 0.020 0.010 5.4 22 3.9 9.8 3.0 05-20-92 26.0 1.6 20 200 8.8 9.1 54 0.030 <0.010 1.6 <0.020 0.030 0.020 6.6 22 3.9 10 2.7 
84 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 2. Water-quality data for Lake Virginia West 28358081210201 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic 

total

(mg/L 

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolve 

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

s

(

 a

03-02-90 20.0 0.68 10 198 10.2 8.2 54 <0.010 <0.010 0.59 0.020 0.040 0.010 3.7 23 3.9 9.3 2.5 04-25-90 25.0 0.15 10 199 8.8 8.9 59 0.020 <0.010 0.57 <0.020 0.040 0.010 4.4 25 4.1 9.5 2.2 06-26-90 31.0 1.7 5 210 -- 8.8 57 0.080 <0.010 1.3 <0.020 0.030 0.020 4.9 24 4.4 10 2.6 09-04-90 30.0 0.82 10 209 6.4 8.2 57 0.020 <0.010 1.2 <0.020 0.030 0.020 5.4 24 4.2 10 2.6 10-24-90 27.5 0.64 10 216 7.0 8.0 60 <0.010 <0.010 0.77 <0.020 0.040 0.020 4.6 24 4.3 11 2.6 12-12-90 18.0 1.2 10 227 9.3 8.0 62 0.010 <0.010 0.69 <0.020 0.040 0.010 5.0 26 4.5 10 2.9 02-28-91 18.0 1.4 10 231 9.0 8.5 66 0.010 <0.010 0.79 0.020 0.020 0.010 4.2 27 4.7 11 2.8 04-30-91 28.5 0.86 5 208 10.5 9.0 59 <0.010 <0.010 1.0 <0.020 0.040 0.020 4.0 24 4.0 10 2.6 06-25-91 30.5 0.51 5 214 9.1 9.0 54 <0.010 <0.010 0.77 <0.020 0.050 0.010 6.2 23 4.1 10 2.8 08-13-91 32.5 1.5 20 192 8.2 8.6 52 <0.010 <0.010 0.85 <0.020 0.030 0.010 5.8 21 3.5 9.0 2.1 10-29-91 25.0 4.4 15 200 7.7 7.8 53 0.020 0.010 1.2 0.020 <0.010 <0.010 5.0 22 3.7 9.2 2.7 12-16-91 19.0 3.0 10 200 7.3 7.7 54 0.020 <0.010 0.79 <0.020 0.050 0.020 5.4 22 3.8 9.6 2.7 02-24-92 20.5 2.2 10 200 9.5 8.1 54 0.010 <0.010 0.69 <0.020 0.020 0.010 5.3 22 3.8 9.9 2.8 05-20-92 26.0 1.6 20 200 9.0 9.1 55 0.020 <0.010 1.6 <0.020 0.030 0.020 6.5 22 3.8 10 2.6 
Appendix 85

Appendix 3. Water-quality data for Lake Mizell 283534081201801[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] 

Date

Temperature 

water

(°C)

Turbidity

(Ntu))

Color

(Pt-Co 

units)

Specific 

conductance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity 

lab 

(mg/L 

as Ca

CO3)

Nitrogen, 

ammonia 

total 

(mg/L as N)

Nitrogen,

 nitrite 

total

 (mg/L

 as N)

Nitrogen, 

ammonia,+ 

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total 

(mg/L as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L) 

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

or

d

so

(mas 

10-04-89 30.0 1.3 5 246 -- 8.2 46 0.010 <0.010 0.81 <0.020 <0.020 0.020 5.7 22 6.8 8.3 9.0 12-13-89 17.5 0.89 5 -- 8.6 7.8 44 <0.010 <0.010 0.84 <0.020 0.040 0.010 4.0 22 6.7 9.0 9.2 03-02-90 20.0 0.66 5 250 8.6 7.7 45 0.030 <0.010 0.62 0.060 0.040 0.010 4.0 23 7.0 9.3 9.5 04-25-90 25.5 0.16 5 260 8.6 8.8 48 0.020 <0.010 0.53 <0.020 0.050 0.010 4.5 24 7.0 9.5 9.2 06-26-90 30.5 0.48 5 252 -- 8.9 48 0.060 <0.010 1.4 <0.020 0.020 0.020 5.2 24 7.2 10 9.2 09-04-90 30.0 0.71 <5 250 6.3 7.6 47 0.010 <0.010 1.3 <0.020 0.030 0.030 5.5 23 6.6 9.5 8.5 10-24-90 28.0 0.56 <5 248 7.7 8.0 47 0.010 <0.010 0.74 <0.020 0.020 0.020 4.9 22 6.5 10 8.4 12-12-90 17.5 0.65 5 254 9.5 7.9 46 0.010 <0.010 0.83 <0.020 0.030 0.010 5.8 23 6.8 10 8.7 02-28-91 18.0 0.96 <5 259 9.4 8.5 49 0.010 <0.010 0.84 0.020 0.020 0.010 4.8 23 6.9 11 8.9 04-30-91 29.0 0.90 10 237 10.8 9.1 48 <0.010 <0.010 1.2 <0.020 0.030 0.020 4.6 22 6.1 9.5 7.7 06-25-91 30.5 0.47 5 243 10.2 9.1 42 0.010 <0.010 1.2 <0.020 0.050 0.020 7.5 21 6.1 9.8 8.1 08-13-91 33.0 1.0 20 229 6.7 8.0 43 <0.010 <0.010 0.83 <0.020 0.020 0.010 6.2 21 5.8 8.8 7.4 10-29-91 25.5 2.1 15 250 9.8 8.4 46 0.020 0.010 1.1 0.020 <0.010 <0.010 5.8 22 6.1 9.0 7.8 12-16-91 18.5 3.5 10 250 7.0 7.6 49 0.010 <0.010 1.1 <0.020 0.020 0.030 6.6 23 6.3 9.2 8.0 02-24-92 21.0 2.3 10 250 9.3 8.4 47 0.020 <0.010 0.83 <0.020 0.020 0.010 5.8 23 6.3 9.8 8.3 05-20-92 26.5 1.2 20 250 9.7 9.4 50 0.030 <0.010 1.7 <0.020 0.030 0.020 7.0 23 6.6 10 8.0 
86 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 4. Water-quality data for Lake Mizell North 283545081201901 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

(PtCo 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

s

03-02-90 20.0 0.77 5 250 8.6 7.7 46 <0.010 <0.010 0.56 0.020 0.040 0.010 4.0 23 7.0 9.0 9.0 04-25-90 25.5 0.24 5 252 9.2 8.9 47 0.020 <0.010 0.51 <0.020 0.040 0.010 4.6 23 7.0 9.6 9.3 06-26-90 30.5 0.48 5 252 -- 7.7 44 0.220 0.010 1.6 <0.020 0.030 0.030 5.6 23 6.7 10 8.9 09-04-90 30.0 0.44 <5 245 5.9 7.5 46 0.010 <0.010 1.2 <0.020 0.030 0.020 5.0 23 6.5 9.3 8.4 10-24-90 27.5 0.25 <5 246 6.7 7.7 46 <0.010 <0.010 0.68 <0.020 0.030 0.020 3.1 22 6.4 10 8.3 12-12-90 18.0 0.52 <5 256 9.2 7.8 46 0.010 <0.010 0.79 <0.020 0.040 0.010 5.7 23 6.8 10 8.7 02-28-91 18.5 1.1 10 259 9.7 8.7 48 0.010 <0.010 0.99 0.020 0.010 0.010 5.0 23 6.9 11 8.8 04-30-91 29.0 0.69 10 234 10.7 9.1 47 <0.010 <0.010 1.3 <0.020 0.040 0.030 4.6 22 6.0 9.3 7.5 06-25-91 31.0 0.83 5 241 9.3 9.1 41 <0.010 <0.010 1.2 <0.020 0.060 0.020 7.9 21 6.1 9.6 7.9 08-13-91 32.5 0.98 20 226 6.2 7.7 43 <0.010 <0.010 0.73 <0.020 0.030 0.010 6.0 21 5.8 8.8 7.4 10-29-91 25.5 1.7 10 249 9.4 8.0 47 0.030 0.010 1.1 <0.020 <0.010 <0.010 5.9 22 6.1 9.0 7.9 12-16-91 19.0 3.9 15 250 7.7 7.7 48 0.020 <0.010 1.0 <0.020 0.060 0.030 6.3 23 6.2 9.3 8.0 02-24-92 21.0 2.1 10 250 9.3 8.4 47 0.020 <0.010 0.97 <0.020 0.030 0.010 6.0 22 6.2 9.7 8.2 05-20-92 26.0 2.1 20 250 10.0 9.4 50 0.030 <0.010 1.7 <0.020 0.040 0.030 7.3 23 6.4 10 8.0 
Appendix 87

Appendix 5. Water-quality for Lake Osceola South 283556081204101[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] 

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

s

(a

10-04-89 30.0 1.5 5 194 -- 8.1 54 0.010 <0.010 0.91 <0.020 <0.020 0.020 5.7 22 3.9 8.5 2.6 12-13-89 17.5 1.0 5 202 8.0 7.8 55 <0.010 <0.010 0.80 <0.020 0.040 0.010 3.9 23 4.0 9.1 2.6 03-02-90 19.5 1.3 10 199 10.0 8.3 57 <0.010 <0.010 0.85 0.020 0.080 0.010 4.2 24 4.1 9.2 2.6 04-25-90 25.0 0.27 5 197 10.5 9.2 59 0.020 <0.010 0.85 <0.020 0.050 0.020 5.0 24 4.1 9.9 2.3 06-26-90 30.0 0.45 5 200 -- 8.9 56 0.300 <0.010 1.3 <0.020 0.040 0.020 5.4 24 4.4 10.0 2.6 09-04-90 30.0 0.58 5 207 7.0 7.7 54 0.010 <0.010 1.7 <0.020 0.030 0.020 5.3 21 3.9 8.8 2.3 10-24-90 27.5 0.62 5 217 7.9 7.9 59 <0.010 <0.010 0.90 <0.020 0.030 0.020 5.2 24 4.4 11 2.5 12-12-90 18.5 1.1 <5 229 7.6 7.6 81 0.010 <0.010 0.70 <0.020 0.030 0.010 1.4 27 4.6 10.0 2.9 02-28-91 17.5 0.94 5 233 9.8 8.7 64 0.010 <0.010 0.71 0.020 0.020 0.010 4.4 27 4.7 11 2.8 04-30-91 28.5 0.94 5 231 11.2 9.1 60 <0.010 <0.010 0.90 <0.020 0.040 0.020 4.0 25 4.3 9.7 2.5 06-25-91 30.0 0.60 5 216 8.8 8.9 52 <0.010 <0.010 1.2 <0.020 0.050 0.010 6.4 22 4.2 9.8 2.7 08-13-91 32.0 1.7 20 198 7.3 8.3 53 <0.010 <0.010 0.74 <0.020 0.020 0.010 5.6 22 3.8 9.0 2.2 10-29-91 25.0 2.3 15 200 9.2 8.0 57 0.030 0.010 1.2 <0.020 <0.010 <0.010 5.0 23 4.0 9.2 2.7 12-16-91 18.5 2.0 5 225 6.1 7.5 59 0.030 <0.010 0.90 <0.020 0.040 0.030 5.5 24 4.2 9.6 2.7 02-24-92 20.5 1.6 10 220 9.5 8.2 58 0.020 <0.010 0.81 0.020 0.160 0.010 5.6 24 4.2 10.0 2.7 04-01-92 19.5 1.3 10 221 0.2 6.8 58 0.090 <0.010 0.84 <0.020 0.090 0.010 4.1 24 4.4 10.0 2.7 05-20-92 26.0 1.5 20 210 9.7 9.2 56 0.020 <0.010 1.6 <0.020 0.030 0.020 6.8 23 4.2 10.0 2.6 
88 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 6. Water-quality for Lake Osceola North 283615081202801 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

d

so

(m

10-04-89 29.5 1.5 5 195 -- 8.2 54 0.010 <0.010 0.96 <0.020 <0.020 0.020 6.2 22 3.9 8.6 2.6 12-13-89 17.5 1.9 5 202 8.3 7.8 53 <0.010 <0.010 0.85 <0.020 0.040 0.010 4.1 23 3.8 9.2 2.7 03-02-90 19.5 1.3 10 200 10.2 8.2 55 <0.010 <0.010 0.73 0.020 0.040 0.010 4.0 24 4.1 9.2 2.6 04-25-90 24.5 0.28 10 200 10.1 9.1 58 0.020 <0.010 1.0 <0.020 0.050 0.020 5.4 23 4.1 9.9 2.3 06-26-90 30.0 0.48 5 203 -- 7.0 51 0.120 <0.010 1.5 <0.020 0.020 0.030 5.9 22 4.4 10.0 2.7 09-04-90 30.0 0.59 <5 204 6.6 8.0 54 0.070 <0.010 1.2 <0.020 0.030 0.020 5.0 23 4.3 10.0 2.6 10-24-90 27.5 0.54 <5 214 7.3 7.9 55 0.010 <0.010 0.83 <0.020 0.030 0.020 4.6 23 4.4 11 2.6 12-12-90 18.0 0.89 10 227 10.8 7.6 56 0.010 <0.010 0.83 <0.020 0.040 0.010 5.0 25 4.5 10.0 3.0 02-28-91 18.0 0.86 <5 230 9.4 8.5 61 0.010 0.010 0.79 0.020 0.020 0.010 4.6 26 4.6 11 2.8 04-30-91 29.0 1.0 5 212 10.3 9.1 57 <0.010 <0.010 1.0 <0.020 0.040 0.020 5.1 24 4.3 10.0 2.5 06-25-91 30.0 0.58 5 214 9.5 9.2 53 <0.010 <0.010 1.2 <0.020 0.050 0.020 6.6 22 4.2 9.8 2.8 08-13-91 32.0 1.1 15 201 6.0 8.2 52 0.010 <0.010 0.76 <0.020 0.020 0.010 5.4 22 3.8 10.0 2.2 10-29-91 25.5 3.7 10 195 8.5 7.8 56 0.020 0.010 1.1 <0.020 0.040 <0.010 5.0 24 4.0 9.3 2.7 12-16-91 18.5 3.6 10 220 7.5 7.9 57 0.010 <0.010 0.86 <0.020 0.020 0.030 5.8 24 4.1 9.7 2.7 02-24-92 20.5 1.6 10 215 9.3 8.2 57 0.030 <0.010 0.81 <0.020 0.020 0.010 5.1 24 4.2 10.0 2.7 05-20-92 25.5 1.3 20 215 9.2 9.2 50 0.030 <0.010 1.6 <0.020 0.030 0.010 8.1 23 4.3 11 2.8 
Appendix 89

Appendix 7. Water-quality data for Lake Maitland South 283644081204901[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] 

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

s

(

 a

10-04-89 29.5 1.7 5 195 -- 8.1 51 0.010 <0.010 0.96 <0.020 <0.020 0.020 6.4 22 3.9 8.7 2.7 12-13-89 17.0 2.0 5 199 7.9 7.8 50 <0.010 <0.010 1.0 0.020 0.060 0.010 1.2 22 3.8 9.3 2.8 03-02-90 19.5 0.90 10 203 9.6 8.0 52 <0.010 <0.010 0.61 0.020 0.040 0.010 3.9 23 4.0 9.4 2.8 04-25-90 25.0 0.17 5 205 8.7 8.2 53 0.020 <0.010 0.47 <0.020 0.040 0.010 5.0 23 4.1 9.9 2.7 06-26-90 30.0 1.1 5 205 -- 8.6 50 0.130 <0.010 1.4 <0.020 0.020 0.020 5.7 22 4.4 11 3.0 09-04-90 29.5 0.59 <5 206 6.1 7.3 53 <0.010 <0.010 0.55 <0.020 0.030 0.020 5.2 23 4.3 10.0 2.9 10-24-90 27.0 0.74 5 209 7.1 7.7 50 <0.010 <0.010 1.0 <0.020 0.030 0.030 6.6 22 4.3 11 2.9 12-12-90 18.0 0.76 10 222 8.3 7.6 52 0.020 <0.010 0.80 <0.020 0.050 0.010 5.2 24 4.4 10.0 3.2 02-28-91 18.0 0.95 <5 228 8.8 8.3 55 0.130 <0.010 0.70 0.020 0.010 0.010 4.8 25 4.4 11 3.4 04-30-91 28.0 0.30 5 214 9.4 8.6 52 0.130 <0.010 0.71 <0.020 0.030 0.020 4.1 24 4.2 10.0 3.0 06-25-91 30.0 0.54 5 216 9.0 8.8 48 <0.010 <0.010 0.90 <0.020 0.050 0.010 6.1 22 4.2 10.0 3.1 08-13-91 31.5 1.7 20 200 7.0 8.4 52 0.010 <0.010 0.76 <0.020 0.030 0.010 5.8 22 3.9 10.0 2.2 10-29-91 25.0 3.9 15 201 8.2 7.7 54 0.010 0.010 1.1 <0.020 <0.010 <0.010 5.2 23 3.9 9.2 2.9 12-16-91 18.5 3.2 10 210 6.2 7.5 55 <0.010 <0.010 0.80 <0.020 0.020 0.030 5.8 23 4.0 9.3 2.8 02-24-92 20.5 1.4 10 210 9.3 7.8 53 <0.010 <0.010 0.68 <0.020 0.020 0.010 4.9 23 4.0 9.8 2.9 05-21-92 26.0 1.2 10 220 9.0 8.7 <0.1 0.030 <0.010 1.4 <0.020 0.020 <0.010 5.8 23 4.2 10.0 2.7 
90 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 8. Water-quality for Lake Maitland West 283708081214201 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

so

(a

 03-02-90 20.0 1.6 10 201 9.8 8.0 50 <0.010 <0.010 0.70 0.020 0.050 0.010 4.3 23 4.0 9.7 2.8 

04-25-90 25.0 0.19 5 202 7.9 8.2 52 0.050 <0.010 0.66 <0.020 0.040 0.010 5.0 22 4.1 10.0 2.8 06-26-90 30.0 1.9 10 205 -- 8.3 50 0.020 <0.010 1.4 <0.020 0.050 0.020 5.6 22 4.2 11 3.4 09-04-90 29.5 0.88 <5 206 7.0 8.1 51 0.010 0.010 1.6 0.020 0.040 0.030 5.6 22 4.3 10.0 3.0 10-24-90 27.0 0.74 5 208 6.8 7.8 50 0.010 <0.010 1.1 <0.020 0.040 0.030 5.8 22 4.3 11 3.0 12-12-90 17.5 1.4 10 220 6.6 7.6 51 0.010 0.030 0.78 <0.020 0.060 0.020 4.9 24 4.4 11 3.3 02-28-91 17.5 2.0 10 230 8.7 7.9 54 0.010 0.010 0.82 0.020 0.040 0.010 5.0 25 4.4 11 3.3 04-30-91 28.5 0.70 5 208 9.0 8.5 52 <0.010 <0.010 0.71 <0.020 0.040 0.020 4.5 24 4.0 10.0 3.0 06-25-91 30.0 0.54 5 210 7.8 8.5 48 <0.010 <0.010 0.83 <0.020 0.050 0.010 5.6 22 3.9 9.8 2.8 08-13-91 31.0 2.2 20 190 7.2 8.8 48 0.010 <0.010 0.85 <0.020 0.030 0.010 6.3 21 3.6 8.8 2.2 10-29-91 24.5 4.1 15 193 10.4 9.1 52 0.040 0.010 1.2 0.020 <0.010 <0.010 6.1 22 3.7 9.0 4.8 12-16-91 17.5 1.3 10 200 7.2 7.7 54 0.020 <0.010 0.80 <0.020 0.040 0.030 6.5 23 3.8 9.3 2.8 02-24-92 20.0 2.0 10 195 9.6 8.0 54 0.020 <0.010 0.63 <0.020 0.020 0.010 5.5 23 3.9 9.6 3.0 05-21-92 26.0 1.4 10 210 8.6 8.6 51 0.020 <0.010 1.2 <0.020 0.030 <0.010 5.4 22 4.1 10.0 2.7 
Appendix 91

Appendix 9. Water-quality data for Lake Maitland North 283545081201901[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported; <, less than] 

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

(Pt-Co 

units)

Specific

 conducta

nce

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L 

as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

s

(m

10-04-89 29.0 1.9 5 192 -- 8.1 49 0.010 <0.010 1.0 <0.020 <0.020 0.020 6.9 21 3.8 8.8 2.8 12-13-89 17.0 1.7 5 198 8.4 7.8 49 <0.010 <0.010 1.0 <0.020 0.050 0.020 2.0 22 3.8 9.4 2.8 03-02-90 19.0 1.5 10 202 9.5 8.0 51 0.010 <0.010 0.63 0.020 0.040 0.010 4.3 23 4.0 9.5 2.9 04-25-90 24.5 0.18 <5 202 7.8 8.1 52 0.020 <0.010 0.62 <0.020 0.040 0.010 5.0 22 4.1 10.0 2.8 06-26-90 30.0 0.84 5 207 -- 8.3 49 0.010 <0.010 1.0 <0.020 0.020 0.020 5.5 22 4.3 11 3.1 09-04-90 29.5 1.2 <5 206 6.5 8.1 51 0.010 <0.010 1.2 <0.020 0.030 0.020 6.1 22 4.3 10.0 3.0 10-24-90 27.0 0.64 5 210 7.8 7.9 50 0.010 0.010 1.0 <0.020 0.040 0.030 6.7 22 4.3 11 3.0 12-12-90 17.5 1.5 10 218 8.3 7.8 51 0.010 <0.010 0.83 <0.020 0.040 0.010 5.5 24 4.4 11 3.3 02-28-91 18.0 1.5 10 230 8.5 7.9 54 0.010 0.010 0.68 0.020 0.020 0.010 5.1 25 4.5 11 3.4 04-30-91 28.0 0.61 5 209 9.0 8.5 50 <0.010 <0.010 0.62 <0.020 0.040 0.020 4.4 23 4.0 10.0 3.0 06-25-91 30.0 0.49 5 209 8.4 8.5 48 <0.010 <0.010 0.97 <0.020 0.050 0.010 6.0 21 4.0 9.8 3.2 08-13-91 31.5 2.0 20 193 7.0 8.4 50 0.010 <0.010 0.85 <0.020 0.040 0.010 6.2 21 3.6 8.8 2.2 10-29-91 25.0 4.4 15 192 8.4 8.1 51 0.020 0.010 1.0 <0.020 <0.010 <0.010 5.7 22 3.7 8.9 2.9 12-16-91 17.5 3.4 15 210 7.3 7.8 53 0.010 <0.010 0.75 <0.020 0.020 0.020 6.1 23 3.9 9.3 2.8 02-24-92 20.0 2.0 10 210 9.5 8.0 53 0.020 <0.010 0.65 0.020 0.200 0.010 5.2 23 3.9 9.6 3.1 05-21-92 25.5 1.6 20 190 8.4 8.1 50 0.020 <0.010 1.0 0.050 0.020 <0.010 5.7 22 4.1 10.0 2.7 
92 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 . Appendix 10. Water-quality data for Lake Sue outflow at Winter Park 02234263 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

 (Pt-Co

units)

Specific

 conduct-ance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L

 as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L

 as P)

Phosphorus, 

ortho 

total

 (mg/L

 as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved

(mg/L 

as K)

10-04-89 30.0 1.2 5 184 -- 7.4 52 0.120 0.010 .95 0.080 <0.020 0.020 6.1 22 3.6 7.8 2.3 12-12-89 17.0 1.1 5 194 8.8 7.5 53 .050 <.010 .90 .040 0.050 .010 4.9 23 3.1 8.6 2.3 03-01-90 20.0 .44 10 185 7.8 7.6 53 .050 <.010 .54 .040 0.050 .010 3.6 22 3.4 9.1 2.0 04-24-90 24.5 -- 10 203 6.9 7.7 62 .050 <.010 .52 .060 0.060 .020 4.3 24 4.2 9.3 1.7 06-25-90 30.0 .64 10 207 -- 7.3 60 .130 .010 1.5 .080 0.040 .020 5.5 24 4.3 10.0 2.4 08-31-90 31.0 .64 5 235 4.9 7.4 75 .110 .030 1.0 .180 0.060 .040 4.3 29 5.3 10.0 2.3 10-23-90 27.0 .74 10 219 4.9 7.5 67 .080 .010 .75 .080 0.060 .040 6.6 26 4.6 10.0 1.9 

12-11-90 16.5 .83 5 294 6.0 7.5 110 .130 .020 .54 .130 0.090 .070 3.5 38 7.5 10.0 1.9 

03-01-91 19.5 .71 <5 285 5.1 7.5 105 .090 .010 .48 .160 0.070 .070 3.3 37 7.5 10.0 1.9 04-29-91 28.0 .41 10 193 7.0 8.0 50 .040 <.010 .82 .090 0.050 .020 4.5 22 3.5 10.0 2.0 06-25-91 29.0 1.2 5 202 3.8 7.3 55 .080 .010 .84 .130 0.060 .020 5.4 23 4.2 9.8 2.5 08-14-91 29.0 .57 20 190 3.6 6.9 53 .090 .010 .75 .140 0.040 .030 4.9 22 3.6 8.8 2.0 10-30-91 22.5 2.6 10 210 3.6 7.0 56 .100 .020 .80 .190 <0.010 <0.01 5.0 23 4.0 9.0 2.4 12-17-91 13.5 1.7 10 205 11.0 7.0 57 .110 .010 .78 .190 .050 .030 5.5 23 3.6 9.8 2.5 02-25-91 20.5 3.9 25 195 4.5 6.8 57 .080 .010 .76 .130 .090 .060 5.7 23 3.4 7.8 2.7 05-19-92 26.5 1.2 10 210 -- 6.9 55 .070 <.010 .77 .150 .090 .020 4.6 22 3.8 11 2.1 
Appendix 93

Appendix 11. Water-quality data for Park Lake outflow 02234287[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported]

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

 (PtCo

units)

Specific

 conductance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L

 as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

 as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

C

o

so

(

 a

10-04-89 30.0 1.3 20 210 -- 7.0 69 0.150 0.020 0.95 0.320 0.040 0.030 8.0 29 3.3 7.1 2.7 12-12-89 17.0 .96 10 222 7.6 7.2 78 .040 <.010 .96 .050 .060 .020 7.3 31 3.1 7.6 2.8 03-01-90 20.0 .60 10 225 7.4 7.6 79 .030 .010 .66 .080 .060 .020 6.0 32 3.5 8.0 2.9 04-24-90 24.5 .15 10 236 5.9 7.7 90 .040 .010 .59 <.020 .070 <.030 6.1 35 3.4 8.4 2.7 06-25-90 30.0 .77 10 225 -- 7.5 78 .020 .010 .90 .020 .060 .020 6.8 29 3.2 7.8 2.6 08-31-90 31.0 .55 20 211 9.4 8.0 76 .040 .010 1.1 .070 .060 .030 4.0 30 3.5 8.7 2.8 10-23-90 27.0 .48 20 231 4.7 7.4 83 .130 .010 .80 .070 .060 .030 8.5 33 3.5 8.5 3.1 

12-11-90 13.5 .34 10 337 7.6 7.4 103 .050 .010 .64 .350 .090 .040 4.6 44 5.0 15 4.0 

04-29-91 28.5 .72 10 211 7.3 8.1 75 .010 <.010 .80 <.020 .050 .020 5.1 29 3.6 7.9 2.4 06-25-91 29.0 .57 5 197 5.0 7.4 64 .050 .010 .67 .210 .070 .030 6.0 26 3.5 8.0 2.5 08-14-91 29.5 1.1 30 196 4.4 7.0 65 .050 .010 .73 .310 .070 .020 5.8 26 3.3 7.4 2.0 10-30-91 22.0 .35 20 385 3.8 6.9 101 1.50 .040 2.1 .210 .160 .080 4.4 44 6.3 18 4.3 12-17-91 14.0 1.4 10 240 6.3 7.3 80 .070 .010 .70 .140 .080 .060 6.1 31 3.7 8.2 2.7 02-25-92 21.5 2.4 10 230 7.2 7.4 80 ..030 .010 .76 .600 .050 .020 6.3 31 3.6 8.0 3.0 05-19-92 28.5 1.5 20 250 -- 8.5 90 .040 <.010 .74 .040 0.100 .040 .5.8 34 4.0 8.7 2.5 
94 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 12. Water-quality data for Lake Minnehaha Outlet 02234299 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

 (PtCo

units)

Specific

 conductance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

10-04-89 28.0 2.7 10 171 -- 7.3 39 0.010 <0.010 0.99 -- <0.020 <0.020 5.7 18 2.8 8.3 2.8 12-12-89 16.5 1.0 10 175 8.1 7.5 40 <.010 <.010 .61 -- .040 .010 6.7 19 2.8 9.0 3.0 03-01-90 18.5 1.5 10 180 8.7 8.0 43 .010 .010 .56 -- .050 .010 5.1 20 3.0 9.4 3.0 04-24-90 23.5 .18 10 185 6.0 7.6 44 .040 <.010 .57 -- .040 .010 5.6 20 3.3 9.7 2.9 08-31-90 30.0 1.4 <5 198 5.1 7.3 48 .010 <.010 1.8 -- .040 .020 2.3 23 3.5 11 3.3 10-23-90 26.0 7.4 20 192 4.2 7.3 45 .010 .010 1.2 -- .100 .030 6.4 21 3.1 10.0 3.1 

12-11-90 14.5 .65 10 214 6.9 7.5 50 .020 <.010 .73 -- .050 .010 6.1 24 3.8 11 3.7 

03-01-91 18.5 .42 5 212 7.6 7.7 44 .010 <.010 .99 .020 .020 .010 5.6 22 4.2 12 3.7 04-29-91 27.5 2.1 20 196 7.5 7.5 43 <.010 <.010 1.1 .370 .060 .030 5.1 21 3.0 10.0 3.0 06-25-91 29.0 .79 5 184 4.4 7.5 45 <.010 <.010 .92 <.020 .050 .020 6.4 21 3.0 9.3 3.4 08-14-91 30.5 1.8 30 172 5.2 7.6 47 .010 <.010 1.2 .030 .040 .020 7.1 20 2.6 8.0 2.3 10-30-91 23.5 4.0 20 195 6.4 7.3 50 .020 .010 .86 .030 <.010 <.010 5.6 22 2.7 8.0 2.9 12-17-91 14.5 1.5 20 200 6.4 7.3 52 .030 <.010 .62 <.020 .050 .020 6.9 23 3.0 8.9 3.2 02-25-92 21.0 2.0 20 195 7.4 7.4 48 .030 <.010 .58 .030 .030 .010 6.3 21 2.7 8.8 3.1 05-19-92 27.0 3.2 20 200 -- 7.2 48 .030 <.010 1.1 .040 .050 .010 5.7 21 2.9 10.0 3.0 
Appendix 95

Appendix 13. Water-quality data for Lake Sue Outflow at Lake Sue 283452081212401[°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported]

Date

Temperature 

water

(°C)

Turbidity

(NTU)

Color

 (PtCo

units)

Specific

 conductance

(μS/cm)

Oxygen, 

dissolve

d

(mg/L)

pH,

Wh,

 field

(SU) )

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total 

(mg/L

 as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calc

ium dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

 as

Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved 

(mg/L 

as K)

Chlo

orid

dis

solv

(mgas C

03-01-90 20.5 .40 10 183 9.1 8.3 51 .020 <.010 .54 .020 .040 .010 3.7 22 3.3 9.1 2.0 15 04-24-90 24.5 .25 5 180 7.9 8.8 49 .020 <.010 .52 <.020 .040 .010 4.8 21 3.2 9.6 1.9 17 06-25-90 31.5 1.6 10 185 -- 8.7 49 .050 <.010 1.8 .030 .020 .020 6.4 21 3.6 11 2.7 18 08-31-90 33.0 .96 5 198 5.4 8.3 55 .090 .010 1.5 .020 .030 .020 4.5 23 3.5 10.0 2.6 17 10-23-90 28.0 0.73 5 199 7.9 8.6 53 .020 <.010 .90 .020 .040 .030 5.5 23 3.5 11 2.5 18 

12-11-90 19.5 .49 10 209 9.5 8.4 56 .040 <.010 .76 <.020 .030 .010 5.4 24 3.6 11 2.7 19 

03-01-91 19.0 .76 <5 210 8.3 8.1 54 .040 <.010 .74 .030 .030 .010 5.0 24 3.6 12 2.6 19 04-29-91 29.0 .51 5 185 9.3 9.1 46 <.010 .010 .75 <.020 .040 .020 4.4 20 3.0 10.0 2.3 18 06-25-91 31.5 1.2 5 180 6.4 8.9 42 .060 .010 1.0 <.020 .050 .010 6.2 19 3.2 9.8 2.8 19 08-14-91 31.0 1.2 10 167 6.4 7.9 44 .040 <.010 .70 <.020 .020 .010 5.1 19 2.7 8.2 1.9 14 10-30-91 24.5 2.2 15 180 8.1 7.8 47 .060 .010 1.2 .020 <.010 <.010 5.3 19 2.9 8.8 2.5 16 12-17-91 17.0 2.6 10 200 5.6 7.3 51 .060 .010 .83 .020 .040 .020 5.9 21 3.0 9.5 2.6 17 02-25-92 21.5 4.2 15 200 7.4 7.6 47 .050 .010 .96 .050 .050 .020 5.3 20 3.0 10.0 2.3 18 05-19-92 27.5 <1.0 10 180 -- 9.1 42 .060 <.010 1.1 .090 .030 .010 5.5 18 2.9 10.0 2.3 18 
96 Water Budgets, Water Quality, and Analysis of Nutrient Loading of the Winter Park Chain of Lakes, Central Florida, 1989-92 Appendix 14. Water-quality data for Lake Maitland outflow 2837270812303501 [°C, degrees Celsius; NTU, nephelometric turbidity units; Pt-Co, Platinum-Cobalt units; μS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter; Wh

micrograms per liter; --, not reported] Date Tem- pera- ture water

(°C)

Turbidity

(NTU)

Color

 (PtCo

units)

Specific

 conductance

(μS/cm)

Oxygen, 

dissolved

(mg/L)

pH,

Wh,

 field

(SU) 

Alkalinity

 lab

(mg/L

 as Ca

CO3)

Nitrogen,

 ammonia 

total

 (mg/L

as N)

Nitrogen, 

nitrite

 total

 (mg/L 

as N)

Nitrogen, 

ammonia, +

organic

total 

(mg/L

as N)

Nitrogen,

NO2

+NO3

total

 (mg/L

 as N)

Phosphorus, 

total

 (mg/L 

as P)

Phosphorus, 

ortho 

total 

(mg/L

as P)

Carbon, 

organic 

total 

(mg/L 

as C)

Calcium 

dissolved

(mg/L

 as Ca)

Magnesium, 

dissolved 

(mg/L)

as Mg)

Sodium, 

dissolved 

(mg/L 

as Na)

Potassium, 

dissolved

(mg/L 

as K)

Chlo

oride

dis

solve

(mg/

 as C

10-04-89 28.0 2.0 5 192 6.4 7.5 47 0.010 <.010 1.0 -- <.020 .020 6.5 21 3.8 8.9 2.8 17 03-01-90 18.0 .60 5 195 8.1 7.6 50 <.010 .010 .61 -- .040 .010 5.6 22 4.0 9.3 2.9 17 04-29-91 27.5 3.0 10 206 8.1 8.2 50 <.010 .010 .70 -- .040 .010 4.6 23 4.1 10.0 2.7 20 06-25-91 29.5 .56 5 203 5.0 7.5 47 .010 <.010 .71 -- .050 .020 5.9 22 4.0 10.0 3.0 20 08-14-91 30.5 1.3 20 192 5.7 7.5 50 .020 <.010 1.0 -- .030 .010 6.1 21 3.4 8.8 2.2 17 10-30-91 23.5 3.0 20 200 7.8 7.3 52 .040 .010 .95 -- .010 <.010 5.8 22 3.7 8.9 2.8 18 12-17-91 13.0 .58 30 300 5.7 7.6 105 .400 .020 1.0 -- .080 .080 9.2 40 4.7 11 4.0 21 02-25-92 21.5 2.0 30 220 5.5 8.3 76 .220 .010 .78 .320 .070 .050 7.9 30 3.0 7.8 3.8 14 05-19-92 29.5 1.7 30 255 -- 9.0 83 .230 .160 1.7 .440 .140 .070 7.8 33 4.2 11 3.7 21 
U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

WATER-RESOURCES INVESTIGATIONS REPORT 95-4108

Bathymetry and littoral vegetation, Lake Maitland--PLATE 1

Phelps, G.G. and German, E.R., 1995, Hydrology, water quality and

constituent budgets of the Winter Park chain of lakes, Florida

PREPARED IN COOPERATION WITH THE

CITY OF WINTER PARK, FLORIDA and

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT

EXPLANATION

LINE OF EQUAL DEPTH BELOW LAKE SURFACE, MARCH 1992--Interval 5 feet. Features 4-M, 8-M and

11-M are possible sinkholes. Datum is lake-surface elevation, about 66 feet above sea level

LITTORAL SEGMENT MIDPOINT AND SPECIES CODE FOR DOMINANT VEGETATION, MARCH

1992--Slashes indicate species are codominant. Parentheses indicate woody species. Dashes indicate no vegetation or no non-woody vegetation. If the dominant specie is woody, the most abundant non-woody specie

is also given. Index to species codes below

Species code Scientific name Common name Species code Scientific name Common name

CAOD Castalia odorata fragrant water lily PAPU Panicum purpurascens para grass

COES Colocasia esculentum elephant ear PARE Panicum repens torpedo grass

CYOD Cyperus odoratus flat sedge POLA Pontederia lanceolata pickerelweed

GRAM Gramineae grass family SALA Sagittaria lancifolia duck potato/arrowhead

HYUM Hydrocotyle umbellata pennywort SCCA Scirpus californicus giant bulrush

MUSP Musa species banana (TADI) Taxodium distichum bald cypress

(MYCE) Myrica cerifera wax myrtle TYSP Typha species cattail

PAHE Panicum hemitomon maidencane

BATHYMETRY AND LITTORAL VEGETATION OF LAKE MAITLAND, MARCH 1992

by

G.G. Phelps and E.R. German

1995

PARE

POLA CAOD

CAOD

PARE

PARE/GRAM

PARE

POLA

PARE

--

CYOD

PARE

GRAM (TADI)

GRAM

--

-- --

CYOD

SALA

PAPU

PARE

GRAM

PARE

MUSP

TYSP

GRAM

PARE

PARE

PARE

PARE/GRAM

PARE

GRAM

PARE

-- --

POLA

TYSP

PARE

PARE/TYSP

PARE/TYSP

PARE

--

HYUM

-- PARE

PARE

-- (TADI)

PARE

TYSP TYSP PARE

POLA

TYSP PARE

PARE -- (TADI)

-- --

TYSP

TYSP

TYSP PARE PARE

PARE

PARE

HYUM

PARE

--

--

--

--

--

PARE

COES

COES

PARE

PAHE

TYSP TYSP

PARE

PARE

TYSP

TYSP

TYSP

PARE

PARE

PARE

CYOD

POLA

POLA PARE

CYOD

TYSP

N

0

0 .25 .5 KILOMETER

.25 .5 MILE

20

20

20

20

20

20

25

15

20

20 15 105

10

5

15

10

10

10

5

5

5

15

15

15

15

PARE/TYSP

PAHE(MYCE)

TYSP

SALA

SALA

HYUM HYUM

SCCA

TYSP/PARE

TYSP

SCCA

SCCA

SALA

SALA

SCCA -- (TADI)

-- (TADI)

-- (TADI)

-- (TADI)

-- (TADI)

-- (TADI)

-- (TADI)

-- (TADI)

CYOD PARE/PAHE

COES

-- (TADI)

-- (TADI)

-- (MYCE)

CAOD(TADI)

8-M

4-M

11-M

N

Lake

Maitland

10

TYSP
U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

WATER-RESOURCES INVESTIGATIONS REPORT 95-4108

Bathymetry and littoral vegetation, Lake Virginia--PLATE 2

Phelps, G.G. and German, E.R., 1995, Hydrology, water quality and

constituent budgets of the Winter Park chain of lakes, Florida

PREPARED IN COOPERATION WITH THE

CITY OF WINTER PARK, FLORIDA and

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT

EXPLANATION

LINE OF EQUAL DEPTH BELOW LAKE SURFACE, MARCH 1992--Interval 5 feet. Datum is lake-surface

elevation, about 66 feet above sea level

LITTORAL SEGMENT MIDPOINT AND SPECIES CODE FOR DOMINANT VEGETATION, MARCH

1992--Slashes indicate species are codominant. Parentheses indicate woody species. Dashes indicate no vegetation or no non-woody vegetation. If the dominant specie is woody, the most abundant non-woody specie

is also given. Index to species codes below

Species code Scientific name Common name Species code Scientific name Common name

CAFL Castalia flava yellow water lily PAPU Panicum purpurascens para grass

CAOD Castalia odorata fragrant water lily PARE Panicum repens torpedo grass

COES Colocasia esculentum elephant ear PASP Panicum species

CYOD Cyperus odoratus flat sedge POLA Pontederia lanceolata pickerelweed

CYPE Cyperaceae sedge family SALA Sagittaria lancifolia duck potato/arrowhead

HYUM Hydrocotyle umbellata pennywort (SASP) Salix species willow

(LUOC) Ludwigia octovalis water primrose SCCA Scirpus californicus giant bulrush

NUAD Nuphar advena yellow cow lily (TADI) Taxodium distichum bald cypress

PAHE Panicum hemitomon maidencane TYSP Typha species cattail

BATHYMETRY AND LITTORAL VEGETATION OF LAKE VIRGINIA, MARCH 1992

by

G.G. Phelps and E.R. German

1995

-- --

--

--

--

PARE

POLA

PARE

PARE

PARE

SALA

SALA/POLA

PARE

PARE

SCCA

-- COES --

POLA

TYSP

POLA

PARE PARE

COES

COES (TADI)

PARE (TADI)

PAHE

TYSP/PAHE

TYSP/PAHE

TYSP/PAHE

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP/PARE

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

NUAD (TADI)

SALA/POLA/CAOD

CYOD

CYPE

NUAD

TYSP

TYSP

PAPU

PARE

--

COES (SASP)

COES

PAHE

PAPU

NUAD

--

--

--

TYSP

TYSP TYSP

TYSP

TYSP

TYSP

PASP

PASP

TYSP

TYSP/(LUOC)

TYSP/(LUOC)

TYSP/PARE

COES

PARE

PARE

COES

CAFL

TYSP/PARE (LUOC)

PARE

PARE --

PAPU

PARE

POLA

PARE/PASP/HYUM

POLA COES

TYSP

0 .25 .5 KILOMETER

0 .25 .5 MILE

20

20

15

10

5

20

5

10

15

20

COES

N

Lake

Virginia

N

10

TYSP
EXPLANATION

LINE OF EQUAL DEPTH BELOW LAKE SURFACE, MARCH 1992--Interval 5 feet. Datum is lake-surface 

elevation, about 66 feet above sea level 

LITTORAL SEGMENT MIDPOINT AND SPECIES CODE FOR DOMINANT VEGETATION, MARCH 

1992--Slashes indicate species are codominant. Parentheses indicate woody species. Dashes indicate no vegetation or no non-woody vegetation. If the dominant specie is woody, the most abundant non-woody specie 

is also given. Index to species codes below 

pecies code Scientific name Common name Species code Scientific name Common name

AOD Castalia odorata fragrant water lily PARE Panicum repens torpedo grass

OES Colocasia esculentum elephant ear PASP Panicum species

YOD Cyperus odoratus flat sedge POLA Pontederia lanceolata pickerelweed

RHE Iris hexagona praire iris SALA Sagittaria lancifolia duck potato/arrowhea

LUOC) Ludwigia octovalis water primrose (SASP) Salix species willow

UAD Nuphar advena yellow cow lily SCCA Scirpus californicus giant bulrush

AHE Panicum hemitomon maidencane (TADI) Taxodium distichum bald cypress

APU Panicum purpurascens para grass TYSP Typha species cattail

10

TYSP

CYOD(LUOC)

TYSP

PAPU

CAOD

CAOD PARE PAHE COES

--

--

--(TADI)

COES

PASP

PASP

PAHE

POLA

PARE

NUAD

PAHE

PAPU

PASP

PASPPASP PARE

PARE

PASP

PARE

CYOD

COES

PASP

COES

TYSP

NUAD

NUAD

NUAD

NUAD/(TADI)

PASP

PARE

PARE

PARE

PARE PARE

SCCA

PARE

PARE PASP

(SASP)/POLA

TYSP

TYSP

TYSP/PARE

NUAD

NUAD

--

--

PARE

PAPU

PASP PAHE

IRHE

CAOD

COES COES

NUAD

NUAD POLA

POLA

CAOD

CAOD

COES

COES(TADI)

SALA/POLA

POLA

POLA

CYOD

CYOD

PARE

PASP

PARE

PASP

CYOD

CYOD

CYOD

CAOD

--

--

--(TADI)

PARE

PARE

PARE

POLA

PAHE/PAPU

PARE

0

0 .25 .5 KILOMETER

.25 .5 MILE

N

20

20

20

20

10

10

10

10

10 5

5

5

15

15

15

15

15

20

20

Lake

Osceola

N
,

ST. JOHNS RIVER WATER MANAGEMENT DISTRICT

EXPLANATION

LINE OF EQUAL DEPTH BELOW LAKE SURFACE, MARCH 1992--Interval 5 feet. Datum is lake-surface 

elevation, about 66 feet above sea level 

LITTORAL SEGMENT MIDPOINT AND SPECIES CODE FOR DOMINANT VEGETATION, MARCH 

1992--Slashes indicate species are codominant. Parentheses indicate woody species. Dashes indicate no vegetation or no non-woody vegetation. If the dominant specie is woody, the most abundant non-woody specie 

is also given. Index to species codes below 

Species code Scientific name Common name Species code Scientific name Common name

CAOD Castalia odorata fragrant water lily PARE Panicum repens torpedo grass

CIME Cicuta mexicana water hemlock POLA Pontederia lanceolata pickerelweed

COES Colocasia esculentum elephant ear SALA Sagittaria lancifolia duck potato/arrowhead

CYOD Cyperus odoratus flat sedge (SASP) Salix species willow

CYPE Cyperaceae sedge family TYSP Typha species torpedo grass

LUOC) Ludwigia octovalis water primrose

BATHYMETRY AND LITTORAL VEGETATION OF LAKE MIZELL, MARCH 1992

10

TYSP

TYSP

--

--

POLA

CAOD

SALA

POLA

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP

TYSP TYSP TYSP

TYSP

TYSP

CIME

TYSP

TYSP

CYOD/PARE/TYSP

COES

TYSP

COES

CIME (SASP)

TYSP

CIME

TYSP

TYSP (SASP)

TYSP

TYSP

COES

TYSP

TYSP

TYSP

SALA

CYPE/CIME

CYPE CYPE

TYSP (LUOC)

TYSP

CAOD (LUOC)

N

0

0 .25 .5 KILOMETER

.25 .5 MILE

20

5

10

15

15

5

10

Lake

Mizell

N