WALTON COUNTY COASTAL DUNE LAKES WATER CHEMISTRY SUMMARY 2016

Transcription

1 WALTON COUNTY COASTAL DUNE LAKES WATER CHEMISTRY SUMMARY 2016 Prepared by Choctawhatchee Basin Alliance in partnership with Mattie Kelly Environmental Institute

2 Contents Overview Northwest Florida Coastal Dune Lakes... 7 Methods of Water Sample and Variable Collection... 9 Water Samples... 9 Secchi Disk... 9 Nutrient Concentration Estimation... 9 Algal Concentration Estimation... 9 Color... 9 Conductivity... 9 Multiparameter Datasonde Allen Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Alligator Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Big Red Fish Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long-term Summary Statistics Long-term Trophic State Variable Trend Analyses Camp Creek Lake, Walton County Lake Description... 20

3 Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Campbell Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through 2016* Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Deer Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Draper Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Eastern Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses... 34

4 Eastern North, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Fuller Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Grayton Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Little Red Fish Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Morris Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through

5 Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Oyster Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Powell Lake, Walton and Bay County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Stallworth Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Tresca Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Western Lake, Walton County Lake Description Water Chemistry Data

6 2016 Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses Western Northeast Lake, Walton County Lake Description Water Chemistry Data Summary Statistics Water Chemistry Data through Long term Summary Statistics Long-term Trophic State Variable Trend Analyses References:... 68

7 Overview Northwest Florida Coastal Dune Lakes Lakes, located along coastlines across the globe, are frequently referred to as coastal dune lakes. Coastal dune lakes, however, are rare as they are found only in select areas of the globe, such as Australia, New Zealand, and the pacific northwest of the United States. Northwest Florida is home to numerous coastal dune lakes with the Walton County Dune Lake Advisory Board identifying 18 named coastal dune lakes in Walton County, Florida. This report also includes monitoring data on Tresca Lake, bringing the total count to 19 lakes. Due to the global scarcity, Northwest Florida s coastal dune lakes have been listed as imperiled by the Florida Natural Areas Inventory. Northwest Florida coastal dune lakes are located within two miles of the coastline with intermittent hydrologic connection to the Gulf of Mexico. These hydrologic connections are known as outlets, or outfalls. When lake level reach flood stage, its waters breach through the sand dunes and flow into the Gulf of Mexico. Typically, lake levels and subsequent outlet openings are dependent on precipitation, runoff, and groundwater conditions. However, strong winds, tides or storms can cause the outlet to open and saltwater inflow or overwash from the Gulf of Mexico to occur. Coastal dune lakes of Northwest Florida reside within the geomorphological province of the Gulf Coastal Lowlands, where undifferentiated siliciclastic sediments occur in significant thickness (less than 6.1 meters). Walton County southern coastline is made up of Holocene sediments consisting of quartz sand, carbonate sands and muds, and organics. This area of Florida resides in the Coastal Strip division of the Apalachicola Delta District, built by sediments deposited by the Apalachicola River. Sediments are composed of medium fine sand, silty sand, silt, and clay representing estuarine facies of the Biloxi Formation. Geologic characteristics may influence the shape of the waterbody basin and, also, contribute to chemical characteristics and trophic state composition of the waterbody (Canfield and Hoyer 1986). Differences in chemical composition of lakes in Florida are furthered explained by lake regions designations specific for the State of Florida. Lake regions of Florida include physical, chemical, and ecological components outlining regions with homogeneity among lake characteristics. Northwest Florida s coastal dune lakes occur in the Gulf Coast Lowlands Lake Region within the East Gulf Coastal Plain Ecoregion. Majority of lakes within these regions are acidic, softwater lakes containing high concentrations of dissolved organic carbons and low to moderate nutrients, comparatively. Coastal dune lakes have higher sulfate, sodium, and chloride levels than inland lakes, and can quickly decrease or increase in salt content depending on shifts in rainfall, saltwater input, or salt spray (Griffith et al. 1997). Majority of Northwest Florida s coastal dune lake watersheds include water flow through forested and wetland areas, increasing the contribution of dissolved organic carbons and tannic acids to the lake water. Dissolved organic carbons and tannic acids derive from slowly

8 decomposing organic matter, which results in more colored, darker water with an acidic, ph condition. Total phosphorus (TP) and total nitrogen (TN) zones were developed to broadly highlight differences in lake nutrient concentrations associated with natural influences like geology. Northwest Florida s coastal dune lakes fall within TP Zone 3 and TN Zone 3. Geometric mean total phosphorus concentration for lakes with TP Zone 3 is 19 µg/l with the 95% range of values being 4 to 39 µg/l. Geometric mean total nitrogen concentration for lakes with TN Zone 3 is 611 µg/l with the 95% range of values being 200 to 1030 µg/l (Bachmann et al. 2012).

9 Methods of Water Sample and Variable Collection A combination of physical and chemical variables were collected at each water quality monitoring station. Open water surface samples were collected in the field and analyzed for nutrients, chlorophyll, color and conductivity at University of Florida s Institute of Food and Agricultural Sciences/SFRC Fisheries and Aquatic Sciences LAKEWATCH National Environmental Laboratory Accredited Certified (NELAC) laboratory. Secchi disk vanishing measurements were recorded and submitted to LAKEWATCH laboratory. In addition, multiparameter datasonde equipment collected surface and bottom water chemistry variables. Water Samples o One, 250-mL, acid-cleaned, triple-rinsed Nalgene bottle is used to collect a water sample that is analyzed for total phosphorus (µg/l), total nitrogen (µg/l) and analyze color (Pt-Co Units) and conductivity (µs/cm). o One, 1000-mL, Nalgene bottle is used to collect a water sample for total chlorophyll analysis. Water is filtered through Gelman 47mm Type A-E glass fiber filter. Secchi Disk Measures the attenuation of light within the water column, or transparency, in meters. Nutrient Concentration Estimation Total Phosphorous (µg/l) The sum of all phosphorus compounds in the water column, organic and inorganic, at the time of collection. Phosphorous is an essential nutrient for alga and plant growth. Total Nitrogen (µg/l) The sum of the all nitrogen compounds in the water column, organic and inorganic, at the time of collection. Nitrogen is an essential nutrient for alga and plant growth. Algal Concentration Estimation Color Total Chlorophyll (µg/l) Sum of all chlorophyll (common pigment found in alga frequently used as a proxy for aquatic flora abundance) in the water column at the time of sampling. True Color The measurement of the color of the water after particles have been filtered out (Platinum-Cobalt Units). Based on the Alpha-Hazen color scale. Conductivity Specific Conductance (µs/cm) The measurement of the ability of water to conduct electricity. Values reported in micro-siemens per centimeter at 25 Celsius.

10 Multiparameter Datasonde Hydrolab Quanta multiparameter datasonde unit was used to measure physical and chemical variables including temperature (C), specific conductivity (µs/cm), dissolved oxygen (mg/l), ph, salinity (PPS), and turbidity (NTU). o Temperature ( C) temperature of the waterbody in degrees Celsius. o Dissolved oxygen (mg/l) concentration of dissolved oxygen in water. o ph the measurement of hydrogen ions within the water, which determine how acidic or basic a waterbody is based on a logarithmic scale. o Salinity (PSS) measurement of dissolved sodium chloride content in the water. Measurements recorded in Practical Salinity Scale. o Turbidity (NTU) the measurement of water clarity within the water column. Turbidity is an optical characteristic of water is measured by the amount of light scattered by material in the water.

11 Allen Lake, Walton County Lake Description Outfall: absent Watershed area: 71 hectares Lake surface area: 7.12 hectares Average depth: 1.1 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 9 samples), total nitrogen (TN) (n = 9 samples), total chlorophyll (CHL) (n = 9 samples), water transparency (Secchi Depth) (n = 9 samples), temperature (n = 9 samples), dissolved oxygen (n = 9 samples), ph (n = 9 samples), salinity (n = 9 samples), turbidity (n = 9 samples), color (n = 2 samples), and (n = 2 samples) specific conductance measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

12 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2003 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

13 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2003 through 2016 for Allen Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2003 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

14 Alligator Lake, Walton County Lake Description Outfall: present Watershed area: 38.4 hectares Lake surface area: 6.43 hectares Average depth: 1.46 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 5 samples), and specific conductance (n = 3 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

15 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2000 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

16 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2000 through 2016 for Alligator Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2000 through 2016). Positive indicates a significant, positive trend as found over time. Negative indicates a significant, negative trend was found among the years examined.

17 Big Red Fish Lake, Walton County Lake Description Outfall: present Watershed area: 119 hectares Lake surface area: 9.22 hectares Average depth: 1.58 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 6 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

18 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1998 through Long-term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

19 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1998 through 2016 for Big Red Fish Lake. These data show the interannual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1998 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

20 Camp Creek Lake, Walton County Lake Description Outfall: present Watershed area: 213 hectares Lake surface area: 23.4 hectares Average depth: 1.58 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 5 samples), and specific conductance (n = 3 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

21 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1992 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

22 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1992 through 2016 for Camp Creek Lake. These data show the interannual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1992 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

23 Campbell Lake, Walton County Lake Description Outfall: present Watershed area: 8.4 hectares Lake surface area: 44.5 hectares Average depth: 3.54 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 11 samples), total nitrogen (TN) (n = 11 samples), total chlorophyll (CHL) (n = 11 samples), water transparency (Secchi Depth) (n = 11 samples), temperature (n = 11 samples), dissolved oxygen (n = 11 samples), ph (n = 11 samples), salinity (n = 11 samples), turbidity (n = 11 samples), color (n = 4 samples), and specific conductance (n = 4 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

24 Water Chemistry Data through 2016* (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1995 through *Between 1997 and 2003, data was not recorded for Campbell Lake. Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

25 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1995 through 2016 for campbell Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1995 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

26 Deer Lake, Walton County Lake Description Outfall: present Watershed area: 127 hectares Lake surface area: 16.9 hectares Average depth: 2.83 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 5 samples), and specific conductance (n = 2 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

27 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1998 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

28 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1998 through 2016 for Deer Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1998 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years

29 Draper Lake, Walton County Lake Description Outfall: present Watershed area: 193 hectares Lake surface area: 11.5 hectares Average depth: 1.4 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 8 samples), total nitrogen (TN) (n = 8 samples), total chlorophyll (CHL) (n = 8 samples), water transparency (Secchi Depth) (n = 8 samples), temperature (n = 8 samples), dissolved oxygen (n = 8 samples), ph (n = 8 samples), salinity (n = 8 samples), turbidity (n = 8 samples), color (n = 5 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

30 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), chlorophyll-a corrected for phenophytin (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1996 through *between 1997 and 2003, nutrient data was not recorded for Draper lake. Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

31 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1996 through 2016 for Draper Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1996 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

32 Eastern Lake, Walton County Lake Description Outfall: present Watershed area: 154 hectares Lake surface area: 25.4 hectares Average depth: 2.10 meters Note: Refers to southern lobe of Eastern Lake Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 10 samples), total nitrogen (TN) (n = 10 samples), total chlorophyll (CHL) (n = 10 samples), water transparency (Secchi Depth) (n = 10 samples), temperature (n = 10 samples), dissolved oxygen (n = 10 samples), ph (n = 10 samples), salinity (n = 10 samples), turbidity (n = 10 samples), color (n = 3 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

33 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1997 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

34 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1997 through 2016 for Eastern Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1997 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

35 Eastern North, Walton County Lake Description Outfall: present through Eastern Lake Watershed area: 154 hectares Lake surface area: 25.4 hectares Average depth: 2.10 meters Note: Refers to northern lobe of Eastern Lake Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 11 samples), total nitrogen (TN) (n = 11 samples), total chlorophyll (CHL) (n = 11 samples), water transparency (Secchi Depth) (n = 11 samples), temperature (n = 11 samples), dissolved oxygen (n = 11 samples), ph (n = 11 samples), salinity (n = 11 samples), turbidity (n = 11 samples), color (n = 3samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

36 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2003 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

37 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2003 through 2016 for Eastern North Lake. These data show the interannual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2003 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

38 Fuller Lake, Walton County Lake Description Outfall: present through Morris Lake Watershed area: 43.3 hectares Lake surface area: hectares Average depth: 1.68 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 4 samples), and specific conductance (n = 4 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

39 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2002 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

40 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2002 through 2016 for Fuller Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2002 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

41 Grayton Lake, Walton County Lake Description Outfall: present Watershed area: 285 hectares Lake surface area: 69.2 hectares Average depth: NA Note: Refers to western lobe of Western Lake Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 4 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

42 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1999 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

43 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1999 through 2016 for Grayton Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1999 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

44 Little Red Fish Lake, Walton County Lake Description Outfall: present Watershed area: NA Lake surface area: 5.02 hectares Average depth: 1.82 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 3 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

45 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2002 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

46 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2002 through 2016 for Little Red Fish Lake. These data show the interannual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2002 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

47 Morris Lake, Walton County Lake Description Outfall: present Watershed area: 86.6 hectares Lake surface area: 31.7 hectares Average depth: 3.07 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 11 samples), total nitrogen (TN) (n = 11 samples), total chlorophyll (CHL) (n = 11 samples), water transparency (Secchi Depth) (n = 11 samples), temperature (n = 11 samples), dissolved oxygen (n = 11 samples), ph (n = 11 samples), salinity (n = 11 samples), turbidity (n = 11 samples), color (n = 4 samples), and specific conductance (n = 4 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

48 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2002 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

49 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2002 through 2016 for Morris Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2002 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

50 Oyster Lake, Walton County Lake Description Outfall: present Watershed area: 56.2 hectares Lake surface area: 8.9 hectares Average depth: 1.7 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 10 samples), total nitrogen (TN) (n = 10 samples), total chlorophyll (CHL) (n = 10 samples), water transparency (Secchi Depth) (n = 10 samples), temperature (n = 10 samples), dissolved oxygen (n = 10 samples), ph (n = 10 samples), salinity (n = 10 samples), turbidity (n = 10 samples), color (n = 3 samples), and specific conductance (n = 2 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

51 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2001 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

52 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2001 through 2016 for Oyster Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2001 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

53 Powell Lake, Walton and Bay County Lake Description Outfall: present Watershed area: hectares Lake surface area: 104 hectares Average depth: 2.01 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 24* samples), total nitrogen (TN) (n = 24 samples), total chlorophyll (CHL) (n = 24 samples), water transparency (Secchi Depth) (n = 24 samples), temperature (n = 17 samples), dissolved oxygen (n = 17 samples), ph (n = 17 samples), salinity (n = 17 samples), turbidity (n = 17 samples), color (n = 4 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data. **Bay County station data collected by St. Andrew Bay Watch of St. Andrew Bay Resource Management Association, Inc., Nutrients, chlorophyll, color and conductivity analyzed by Florida LAKEWATCH laboratory. Because Powell Lake is sampled both by Walton County s CBA as well as Bay County s RMA, the total number of monthly samples is greater than Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA

54 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 1992 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) NA Specific Conductance (µs/cm) NA

55 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 1992 through 2016 for Powell Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (1992 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

56 Stallworth Lake, Walton County Lake Description Outfall: present Watershed area: 86.1 hectares Lake surface area: 5.22 hectares Average depth: 1.5 meters Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 12 samples), total nitrogen (TN) (n = 12 samples), total chlorophyll (CHL) (n = 12 samples), water transparency (Secchi Depth) (n = 12 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 4 samples), and specific conductance (n = 4 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

57 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2001 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

58 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2001 through 2016 for Stallworth Lake. These data show the interannual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2001 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

59 Tresca Lake, Walton County Lake Description Outfall: absent Watershed area: NA Lake surface area: NA Average depth: NA Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 11 samples), total nitrogen (TN) (n = 11 samples), total chlorophyll (CHL) (n = 11 samples), water transparency (Secchi Depth) (n = 11 samples), temperature (n = 12 samples), dissolved oxygen (n = 12 samples), ph (n = 12 samples), salinity (n = 12 samples), turbidity (n = 12 samples), color (n = 4 samples), and specific conductance (n = 4 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

60 Water Chemistry Data through 2016 (Std Error) summary statistics calculated on an annual basis using monthly data for total phosphorous (TP), total nitrogen (TN), total chlorophyll (CHL), water transparency (Secchi Depth), temperature, dissolved oxygen, ph, salinity, turbidity, color, and specific conductance. Summary statistics represent long-term analyses among annual means from 2008 through Long term Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm)

61 Long-term Trophic State Variable Trend Analyses Monthly total phosphorous (µg/l), total nitrogen (µg/l), total chlorophyll (µg/l) and water transparency (m) from 2008 through 2016 for Tresca Lake. These data show the inter-annual (monthly variability within the year - circles) and intra-annual variance (variability among years - triangles). Kendall-Tau trend analysis results are shown for total phosphorus, total nitrogen, total chlorophyll, and water transparency on the top-left of each plot. Not significant indicates there was no significant trend found among the years examined (2008 through 2016). Positive indicates a significant, positive trend was found over time. Negative indicates a significant, negative trend was found among the years examined.

62 Western Lake, Walton County Lake Description Outfall: present Watershed area: 275 hectares Lake surface area: 69 hectares Average depth: 2.16 meters Note: Refers to eastern lobe of Western Lake Water Chemistry Data (Std Error) calculated for total phosphorous (TP) (n = 10 samples), total nitrogen (TN) (n = 10 samples), total chlorophyll (CHL) (n = 10 samples), water transparency (Secchi Depth) (n = 10 samples), temperature (n = 10 samples), dissolved oxygen (n = 10 samples), ph (n = 10 samples), salinity (n = 10 samples), turbidity (n = 10 samples), color (n = 3 samples), and specific conductance (n = 0 samples) measurements. These statistics represent 2016 water chemistry data Summary Statistics TP (µg/l) TN (µg/l) CHL (µg/l) Secchi Depth (m) Temperature (C) Dissolved Oxygen (mg/l) ph Salinity (ppt) Turbidity (NTU) Color (Pt-Co units) Specific Conductance (µs/cm) NA NA NA NA NA