S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T Water Flow and Nutrient Loads to Lake Okeechobee and the St. Lucie and Caloosahatchee Estuaries in Water Years 2014-2018 St Lucie Estuary Stuart and Sewall’s Point Governing Board Meeting South Florida Water Management District October 11, 2018 Stuart Van Horn, P.E. – Bureau Chief, Water Quality S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 2 Flow and Nutrient Loads to Lake Okeechobee and St Lucie and Caloosahatchee Estuaries Presentation Content Water Year 2018 (May 2017 – April 2018) Update • Extraordinary WY2018 Wet Season Hydrologic Conditions • Lake Okeechobee and Estuary Inflow and Nutrient Loads • Long-term Trends for Lake Okeechobee and Estuary Inflows Kissimmee River S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 3 Flow and Nutrient Loads to Lake Okeechobee and St Lucie and Caloosahatchee Estuaries Rainfall Driving Stages and Flows WY2017 WY2019 WY2018 16 • Extremely dry antecedent conditions prior to the start of WY2018 6.72 12 6.30 8 7.64 1.30 0.51 0.10 1.09 0.38 1.71 3.44 4 0.05 0.80 0.24 1.88 0.72 2.15 0.88 0.77 0.88 0.68 0.82 0.65 1.43 2.13 0 • WY2018 wet season was the wettest on record since 1932 with 51.5” rain Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug District Rainfall = 63.7” Remnant TS Beatriz (June 2017) Hurricane Irma (Sep 2017) TS Philippe (Oct 2017) S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 4 Flow and Nutrient Loads to Lake Okeechobee and St Lucie and Caloosahatchee Estuaries Major Climatic Events WY2018 Wet Season Remnants of TS Beatriz June 5 – 7, 2017 Rainfall = 1.5” Rainfall = 3.8” Hurricane Irma September 10, 2017 Rainfall = 1.4” Rainfall = 5.0” Hurricane Irma Path TS Philippe October 28, 2017 Rainfall = 2.5” S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 5 Flow and Nutrient Loads to Lake Okeechobee and St Lucie and Caloosahatchee Estuaries Rainfall Distribution During Major Rainfall Events September 2017 Rainfall June 2017 Rainfall Events Leading to a Historic Wet Season SFWMD Rainfall 02-Jun-2017 to 01-Jul-2017 SFWMD Rainfall 02-Sep-2017 to 01-Oct-2017 October 2017 Rainfall SFWMD Rainfall 02-Oct-2017 to 01-Nov-2017  Dry season through May ’17 suggested potential drought  High Water Emergency Order issued Jun ’17 resulting from high rainfall for the month  Jun-Oct wet season rainfall 150% above average (+17.3”) TS Beatriz DISTRICT-WIDE: 14.97” (181%, +6.72”) Hurricane Irma DISTRICT-WIDE: 13.27” (190%, +6.30”) TS Philippe DISTRICT-WIDE: 7.45” (186%, +3.44”) Measured (% of Avg, Diff From Avg.) S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 6 Flow and Nutrient Loads to Lake Okeechobee Wet and Dry Seasons Contrast Water Year 2018 DRY SEASON WET SEASON 0.0 1.0 2.0 Above average rainfall 3.0 4.0 Max. Stage 17.2 ft Below average rainfall 18 High Lake Management Low 14 Base Flow 10 Water Shortage Management 60 40 20 0 TS Beatriz 80 Increasing inflows to Lake TS Philippe Beneficial Use Hurricane Irma 12 Operation Band High Intermediate 16 Inflows to Lake Low Flow into and out of Lake Release East/West Release South S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 7 Lake Okeechobee Inflows Water Year 2018 Nitrogen Flow Phosphorus 6% 5% 0% 7% 5% 0% 14% 5% 0% 89% 81% 89% 3.4 million ac‐ft 20 TS Beatriz 40 248 µg/L 1.78 mg/L TS Philippe 60 Hurricane Irma 80 • North watershed: 89% of total annual inflow • 83% of all inflow occurred in wet season 0 North Lake South Lake East Lake West Lake µg/L = ppb mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T St. Lucie Estuary *Due to the unavailability of USGS data, flow volumes reported for S‐308   October 8 through December 6, 2018, appear to overestimate contributions  from Lake Okeechobee and underestimate C‐44 Basin runoff. Water Year 2018 Phosphorus 37% 29% 8% 12% 37% 51% 286 µg/L 20 10 8% 12% 38% 1.6 million ac‐ft 43% 1.61 mg/L TS Philippe 5% 20% Nitrogen Hurricane Irma 30 Flow* TS Beatriz Total Flow (thousand ac‐ ) 40 8 Lake Okeechobee • Local basin runoff: 63% of total inflow • 75% of all inflow occurred in wet season 0 Lake Okeechobee Inflow C‐44 Basin Runoff C‐23, C‐24, Ten Mile Creek Inflows Tidal Basin Inflow µg/L = ppb mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 9 Caloosahatchee Estuary Water Year 2018 Nitrogen Phosphorus 39% 30% 40% Lake Okeechobee 12% 60 11% 40 45% 3.1 million ac‐ft 30 20 10 58% 170 µg/L 49% Hurricane Irma 50 TS Beatriz Total Flow (thousand ac‐ ) 16% 1.41 mg/L TS Philippe Flow • Local basin runoff: 61% of total inflow • 70% of all inflow occurred in wet season 0 Lake Okeechobee Inflow C‐43 Basin Runoff Tidal Basin Inflow µg/L = ppb mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 10 Lake Okeechobee Inflow WY2014-WY2018 Phosphorus UPPER KISSIMMEE 32% Water; 15% TP Load TP Load TP FWMC 90 mt 78 µg/L 5-YEAR AVERAGE LAKE ISTOKPOGA 14% Water; 8% TP Load TP Load TP FWMC 48 mt 95 µg/L INDIAN PRAIRIE 17% Water; 21% TP Load TP Load TP FWMC 126 mt 201 µg/L 13% Water; 17% TP Load TP Load TP FWMC 103 mt 219 µg/L TC-NS 7% Water; 19% TP Load FISHEATING CREEK TP FWMC 72 mt 177 µg/L Lake Okeechobee WEST LAKE O. TP FWMC 0.02 mt 115 µg/L TP FWMC 114 mt 470 µg/L 2% Water; 3% TP Load <1% Water; <1% TP Load TP Load TP Load EAST LAKE O. 11% Water; 12% TP Load TP Load Northern watershed contributes: ~ 95% of flow and ~ 92% TP load LOWER KISSIMMEE Source: Draft 2019 South Florida Environmental Report, Appendix 8B-2 TP Load TP FWMC 17 mt 196 µg/L SOUTH LAKE O. 3% Water; 5% TP Load TP Load TP FWMC 29 mt 266 µg/L µg/L = ppb S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 11 Lake Okeechobee Inflow WY2014-WY2018 Nitrogen UPPER KISSIMMEE 32% Water; 26% TN Load TN Load TN FWMC 1,418 mt 1.22 mg/L 5-YEAR AVERAGE LAKE ISTOKPOGA 14% Water; 14% TN Load TN Load TN FWMC 770 mt 1.53 mg/L INDIAN PRAIRIE 17% Water; 12% TN Load TN Load TN FWMC 655 mt 1.04 mg/L 13% Water; 19% TN Load TN Load TN FWMC 1,033 mt 2.21 mg/L TC-NS 7% Water; 8% TN Load FISHEATING CREEK TN FWMC 604 mt 1.47 mg/L Lake Okeechobee WEST LAKE O. TN FWMC 0.25 mt 1.56 mg/L TN FWMC 449 mt 1.86 mg/L 2% Water; 3% TN Load <1% Water; <1% TN Load TN Load TN Load EAST LAKE O. 11% Water; 11% TN Load TN Load Northern watershed contributes: ~ 95% of flow and ~ 89% TN load LOWER KISSIMMEE Source: Draft 2019 South Florida Environmental Report, Appendix 8B-2 TN Load TN FWMC 170 mt 1.99 mg/L SOUTH LAKE O. 3% Water; 8% TN Load TN Load TN FWMC 441 mt 4.05 mg/L mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T St Lucie Estuary Inflow Phosphorus WY2014-WY2018 12 *Due to the unavailability of USGS data, flow volumes reported for S‐308   October 8 through December 6, 2018, appear to overestimate contributions  from Lake Okeechobee and underestimate C‐44 Basin runoff. 5-YEAR AVERAGE TEN MILE CREEK 10% Water; 12% TP Load TP Load TP FWMC 41 mt 296 µg/L Local Basin Runoff accounted for about 69% of flow and 77% of TP load to Estuary*. TIDAL BASINS (ESTIMATED) 23% Water; 10% TP Load C-24 12% Water; 17% TP Load TP Load TP FWMC 58 mt 334 µg/L TP Load TP FWMC 35 mt 104 µg/L C-23 12% Water; 20% TP Load TP Load TP FWMC 66 mt 404 µg/L LAKE OKEECHOBEE* C-44* 31% Water; 23% TP Load 12% Water; 18% TP Load TP Load TP FWMC TP Load TP FWMC 77 mt 174 µg/L 61 mt 347 µg/L Source: Draft 2019 South Florida Environmental Report, Appendix 8C-1 µg/L = ppb S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T St Lucie Estuary Inflow Nitrogen WY2014-WY2018 13 *Due to the unavailability of USGS data, flow volumes reported for S‐308   October 8 through December 6, 2018, appear to overestimate contributions  from Lake Okeechobee and underestimate C‐44 Basin runoff. 5-YEAR AVERAGE TEN MILE CREEK 10% Water; 7% TN Load TN Load TP FWMC 145 mt 1.05 mg/L Local Basin Runoff accounted for about 69% of flow and 64% of TN load to Estuary*. C-24 12% Water; 14% TN Load TN Load TN FWMC 265 mt 1.52 mg/L TIDAL BASINS (ESTIMATED) 23% Water; 16% TN Load TN Load TN FWMC 307 mt 0.92 mg/L C-23 12% Water; 14% TN Load TN Load TN FWMC 268 mt 1.63 mg/L LAKE OKEECHOBEE* C-44* 31% Water; 36% TN Load 12% Water; 13% TN Load TN Load TN FWMC TN Load TN FWMC 694 mt 1.57 mg/L 262 mt 1.49 mg/L Source: Draft 2019 South Florida Environmental Report, Appendix 8C-1 mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 14 Caloosahatchee Estuary Inflows Phosphorus WY2014-WY2018 5-YEAR AVERAGE TIDAL BASIN (ESTIMATED) Local Basin Runoff accounted for about 62% of flow and 70% of TP load to Estuary LAKE OKEECHOBEE 38% Water; 30% TP Load 18% Water; 12% TP Load TP Load TP FWMC 47 mt 89 µg/L TP Load TP FWMC 112 mt 97 µg/L C-43 AND S-4 BASINS TO ESTUARY 44% Water; 58% TP Load TP Load TP FWMC 220 mt 165 µg/L Note: Coastal Basin runoff (west of Shell Point) is not included as Estuary contribution. Source: Draft 2019 South Florida Environmental Report, Appendix 8C-1 µg/L = ppb S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 15 Caloosahatchee Estuary Inflows Nitrogen WY2014-WY2018 5-YEAR AVERAGE TIDAL BASIN (ESTIMATED) Local Basin Runoff accounted for about 62% of flow and 60% of TN load to Estuary LAKE OKEECHOBEE 38% Water; 40% TN Load 18% Water; 14% TN Load TN Load TN FWMC 523 mt 0.99 mg/L TN Load TN FWMC 1,574 mt 1.36 mg/L C-43 AND S-4 BASINS TO ESTUARY 44% Water; 46% TN Load TN Load TN FWMC 1,799 mt 1.35 mg/L Note: Coastal Basin runoff (west of Shell Point) is not included as Estuary contribution. Source: Draft 2019 South Florida Environmental Report, Appendix 8C-1 mg/L = ppm S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 16 Long-term Flow-weighted Mean Phosphorus Concentration Trends Lake Okeechobee and St. Lucie Estuary and Calooshatchee Estuary WY1999-2008 Flow‐Weighted Mean TP (µg/L) 400 WY2009-2018 10‐Year FWM 181 µg/L 300 Lake Okeechobee Inflows • 10‐Year FWM 170 µg/L 200 Trend Line 100 • FWM TP concentration for last 10 years is 6% lower than previous 10-year period General downward trend over 20-year period Lake Okeechobee 0 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 St. Lucie Estuary Inflows* Flow‐Weighted Mean TP (µg/L) 400 300 Trend Line 200 10‐Year FWM 315 µg/L 100 • • 10‐Year FWM 289 µg/L St. Lucie Estuary 0 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Caloosahatchee Estuary Inflows* 400 Flow‐Weighted Mean TP (µg/L) FWM TP concentration for last 10 years is 8% lower than previous 10-year period General downward trend over 20-year period 10‐Year FWM 139 µg/L 300 • 10‐Year FWM 140 µg/L 200 Trend Line 100 Caloosahatchee Estuary 0 1999 2001 2003 2005 2007 2009 2011 Water Year (May ‐ April) 2013 2015 2017 • • No apparent difference in FWM TP concentrations between last 10 years and previous 10-year period Lower variability in concentrations last 10 years General downward trend over 20-year period * Excluding Tidal Portions of St. Lucie and Caloosahatchee Estuaries Source Data: South Florida Environmental Reports µg/L = ppb; FWM = Flow-Weighted Mean S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 17 Long-term Flow-weighted Mean Nitrogen Concentration Trends Lake Okeechobee and St. Lucie Estuary and Calooshatchee Estuary WY1999-2008 Flow‐Weighted Mean TN (mg/L) 3.0 WY2009-2018 Lake Okeechobee Inflows Lake Okeechobee 10‐Year FWM 1.71 mg/L 2.5 • 10‐Year FWM 1.62 mg/L 2.0 • 1.5 FWM TN concentration for last 10 years is 5% lower than previous 10-year period General downward trend over 20-year period Trend Line 1.0 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 St. Lucie Estuary Inflows* Flow‐Weighted Mean TN (mg/L) 3.0 St. Lucie Estuary 10‐Year FWM 1.70 mg/L 2.5 • 10‐Year FWM 1.56 mg/L 2.0 • Trend Line 1.5 1.0 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 Caloosahatchee Estuary Inflows* 3.0 Flow‐Weighted Mean TN (mg/L) FWM TN concentration for last 10 years is 8% lower than previous 10-year period General downward trend over 20-year period Caloosahatchee Estuary 2.5 10‐Year FWM 1.47 mg/L 2.0 • 10‐Year FWM 1.38 mg/L 1.5 Trend Line 1.0 1999 2001 2003 2005 2007 2009 2011 Water Year (May ‐ April) 2013 2015 2017 • • FWM TN concentration for last 10 years is 6% lower than previous 10-year period Lower variability in concentrations last 10 years General downward trend over 20-year period * Excluding Tidal Portions and 10-Mile Creek of St. Lucie and Tidal Portions of Caloosahatchee Estuaries Source Data: South Florida Environmental Reports µg/L = ppb; FWM = Flow-Weighted Mean S O U T H   F L O R I D A   W A T E R   M A N A G E M E N T   D I S T R I C T 18 Flow and Nutrient Loads to Lake Okeechobee and St Lucie and Caloosahatchee Estuaries Summary • Historic wet conditions in WY2018 resulted in significant wet season runoff and nutrient loads for all three watersheds • Basins north of Lake Okeechobee contributed 89% of the total flow during WY2018 and 94% over the 5-year average period • Annual sub-watershed data WY2014-2018 available at South Florida Environmental Report (Ch. 8B & 8C) www.sfwmd.gov/sfer Questions? Caloosahatchee River Estuary