WaterWater QualityQuality TrendsTrends ofof thethe KissimmeeKissimmee ChainChain ofof Lakes,Lakes, LakeLake IstokpogaIstokpoga andand LakeLake OkeechobeeOkeechobee

R. Thomas James, Brad Jones, Paul McCormick South Water Management District

Clell Ford Highlands County, Florida

and

Karl Havens Florida Sea Grant University of Florida

1 ObjectivesObjectives

„ EvaluateEvaluate longlong termterm datadata forfor thethe KissimmeeKissimmee ChainChain ofof Lakes,Lakes, LakeLake Istokpoga,Istokpoga, LakeLake OkeechobeeOkeechobee „ DetermineDetermine ifif trendstrends existexist inin „ Nutrients „ Turbidity and Transparency „ Chlorophyll „ Conductivity and Ions „ DetermineDetermine relationshipsrelationships amongamong lakeslakes „ LookLook forfor causalitycausality WatershedWatershed

„ Drainage Area 13,859 km2 „ 6 regions „ 61 basins „ Landuse „ Natural „ Agricultural „ Residential „ Changed over time UpperUpper ChainChain ofof LakesLakes

East

„ Headwaters of „ Sampling began in 1981 „ Lakes interconnected by canals „ Water Levels Regulated „ Hydrilla Increased through the 1990s „ Chemical control has been partially effective „ Lakewide treatments in late 90s „ Hurricanes and turbidity helped to control in the 2000s LakeLake IstokpogaIstokpoga

„ Fifth largest Lake in Florida „ Sampled since 1988 „ Outflow Structure built in 1961 „ Waters regulated within a few feet LakeLake OkeechobeeOkeechobee

„ Largest Lake In Southeast „ 1730 km2 „ Shallow „ Sampled since 1973 „ Surrounded by Herbert Hoover Dike „ All inflow and outflows except are regulated SamplingSampling

„ SamplesSamples takentaken onon aa monthlymonthly basisbasis „ WaterWater samplessamples analyzedanalyzed forfor ions,ions, nutrientsnutrients andand chlorophyllchlorophyll usingusing standardstandard methodsmethods „ TransparencyTransparency measuredmeasured withwith aa SecchiSecchi DiskDisk AnalysisAnalysis

„ KendallKendall’’ss TauTau analysisanalysis „ GraphicsGraphics „ TimelinesTimelines „ FitFit withwith 22nd orderorder polynomialpolynomial curvecurve SignificantSignificant TrendsTrends 19811981 toto 20072007

Parameter East Tohopekaliga Tohopekaliga Cypress Hatchineha Kissimmee CA 0.2533 CL SULFATE -0.2322 -0.3937 -0.1806 -0.2154 SCOND -1.8571 TURB -0.0333 -0.3700 SECCHI 0.0150 SI -0.0238 -0.0617 -0.0190 TP -0.0045 -0.0021 SRP 0.0000 TN -0.0437 -0.0179 -0.0094 DIN 0.0004 0.0003 0.0003 CHLA -0.1857 -2.9379 -0.9873 EastEast LakeLake TohopekaligaTohopekaliga

0.08 3.5 0.07 3 0.06 2.5

0.05 2 0.04 1.5 0.03 1 0.02 Secchi Disk Depth (m) Depth Disk Secchi 0.5 Total Phosphorus (mg/l) Phosphorus Total 0.01 0 0 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08

2.5 45 40 2 35 g/l) μ

( 30

1.5 a 25 20 1 15

Chlorophyll 10

Total Nitrogen (mg/l) Nitrogen Total 0.5 5 0 0 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 LakeLake TohopekaligaTohopekaliga

0.8 2.5 0.7 2 0.6

0.5 1.5 0.4 0.3 1 0.2 0.5 Secchi Disk Depth Disk (m)) Secchi

Total Phosphorus (mg/l) Phosphorus Total 0.1 0 0 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 300 7 250 6

g/l) 200 5 μ ( a 4 150

3 100 2 Chlorophyll Chlorophyll 50 Total Nitrogen (mg/l) Nitrogen Total 1 0 0 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-08 LakeLake CypressCypress

0.35 1.8

0.3 1.6 1.4 0.25 1.2 0.2 1 0.15 0.8 0.6 0.1 0.4 Secchi Disk Depth (m) Depth Disk Secchi Total Phosphorus (mg/l) Phosphorus Total 0.05 0.2 0 0 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06

6 250

5 200 g/l) μ

4 (

a 150 3 100 2 Chlorophyll Chlorophyll Total Nitrogen (mg/l) 1 50

0 0 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 LakeLake HatchinehaHatchineha

0.18 2.5 0.16 2 0.14 0.12 1.5 0.1 0.08 1 0.06 0.04 0.5 Secchi Disk Depth (m) Depth Disk Secchi

Total Phosphorus (mg/l) Phosphorus Total 0.02 0 0 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06

7 2.5

6 2.0 g/l)

5 μ (

a 1.5 4

3 1.0

2

Chlorophyll 0.5 Total Nitrogen (mg/l) 1

0 0.0 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 LakeLake KissimmeeKissimmee

0.16 2.0 0.14 1.8 1.6 0.12 1.4 0.1 1.2 0.08 1.0 0.06 0.8 0.6 0.04 0.4 Secchi Disk Depth (m) Disk Secchi Total Phosphorus (mg/l) Phosphorus Total 0.02 0.2 0 0.0 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06

3 140

2.5 120

g/L) 100 μ

2 (

a 80 1.5 60 1 40 Total Nitrogen (mg/l) Nitrogen Total 0.5 Chlorophyll 20

0 0 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 Jan-82 Jan-85 Jan-88 Jan-91 Jan-94 Jan-97 Jan-00 Jan-03 Jan-06 SignificantSignificant TrendsTrends 19811981 toto 19941994

Parameter East Tohopekaliga Tohopekaliga Cypress Hatchineha Kissimmee CA 0.3111 0.6500 CL 0.4500 SULFATE -0.4111 SCOND 3.5000 TURB -0.4000 SECCHI 0.0182 0.0157 0.0167 SI -0.0250 TP -0.0160 -0.0085 -0.0028 -0.0028 SRP 0.0001 -0.0013 TN -0.1103 -0.0671 -0.0443 -0.0373 DIN -0.0004 -0.0020 -0.0006 CHLA -5.4083 -2.3222 SignificantSignificant TrendsTrends 19941994 toto 20072007

Parameter East Tohopekaliga Tohopekaliga Cypress Hatchineha Kissimmee CA 0.3667 CL 0.5509 0.4762 SULFATE -0.4250 SCOND 1.8571 TURB -0.0869 0.2397 SECCHI -0.0286 -0.0200 SI -0.0563 -0.0570 -0.0792 TP 0.0026 0.0033 0.0030 SRP 0.0004 TN -0.0170 0.0258 DIN CHLA SignificantSignificant TrendsTrends 19811981 (1988*)(1988*) -- 20072007

Parameter Istokpoga* Okeechobee CA CL -1.8074

SULFATE 0.2777

SCOND -10.0128 TURB 0.2502 0.8465

SECCHI -0.0293 -0.0113 SI -0.1255 TP 0.0018 0.0026 SRP 0.0011 TN 0.0233 DIN 0.0023 CHLA 1.2636 LakeLake IstokpogaIstokpoga

0.30 1.8 0.25 1.6 1.4 0.20 1.2

0.15 1 0.8 0.10 0.6 0.4 0.05

Secchi Disk Depth (m) Depth Disk Secchi 0.2 Total Phosphorus (mg/l) Phosphorus Total 0.00 0 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08

3.0 100 90 2.5 80 2.0 70 g/l) 60 μ (

1.5 a 50 40 1.0 30 20

0.5 Chlorophyll Total Nitrogen (mg/l) Nitrogen Total 10 0.0 0 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 LakeLake OkeechobeeOkeechobee

0.5 1.4 1.2 0.4 1.0 0.3 0.8 0.2 0.6 0.4 0.1 0.2 Secchi Disk Depth (m) Depth Disk Secchi

Total Phsoprhorus (mg/L) Phsoprhorus Total 0 0.0 Jan-81 Jan-84 Jan-87 Jan-90 Jan-93 Jan-96 Jan-99 Jan-02 Jan-05 Jan-81 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07

3.5 g/L)

μ 60

3.0 ( 50 2.5 a 40 2.0 30 1.5 1.0 20

Total Nitrogen (mg/L) Nitrogen Total 0.5 10 Chloropyhyll 0.0 0 Jan-81 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-81 Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 SummarySummary

„ UpperUpper ChainChain ofof LakesLakes „ LakeLake TohopekaligaTohopekaliga hadhad greatestgreatest trendstrends „ Related to diversion of effluent from sewage treatment plant „ Led to improvements downstream „ ImprovementsImprovements reachedreached aa plateauplateau inin 19941994 „ Hydrilla „ Increased population SummarySummary

„ LakeLake IstokpogaIstokpoga „ IncreasedIncreased nutrients,nutrients, reducedreduced lightlight „ Hydrilla „ Nutrient Loading „ LakeLake OkeechobeeOkeechobee „ IncreasedIncreased nutrients,nutrients, turbidity,turbidity, reducedreduced lightlight „ Excessive nutrient loads „ Sediment buffer „ Phytoplankton light limited? Questions?Questions?