Water Management in Lake Okeechobee & the Water Conservation Areas - supporting the Northern Estuaries and Everglades Restoration

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1 Department of the Interior - DOI Everglades Restoration Initiatives Water Management in Lake Okeechobee & the Water Conservation Areas - supporting the Northern Estuaries and Everglades Restoration Robert Johnson & Shannon Estenoz Joint Water Advisory Board & Technical Advisory Committee Meeting, March 19, 2015

2 Chronology of Water Management Changes Everglades Agricultural Area Everglades National Park WCA 3A WCA 3B Lox. NWR WCA 2A 2B Pre-C&SF Projects Caloosahatchee River Connection 1883 Major East Coast Canals s Hoover Dike/Saint Lucie Canal 1930 s Post-C&SF Projects Eastern Protective Levee System 1953 Everglades Ag. Area Levees Water Conservation Area Levees 1968 South Dade Conveyance System 1980 s Water Management Chronology, source: Light and Dineen, 1994 Reconstructed Pre-drainage Landscapes, source: McVoy et. al., 2011.

3 Alterations in Surface Water Flow Volumes through the Everglades Shark River Sloug h River of Grass Restoration Planning Workshops, source: SFWMD, 2010.

4 Central and Southern Florida (C&SF) Project Water Flow and Design Capacity Issues 1, , Lake Okeechobee 730 mi 2 Average Annual inflows 1.5 M ac - ft, outflows 1.25M ac - ft, effective storage capacity of ~ 2,250,000 acre - feet. Inflow Capacity ~40,000 cfs > Outflow 16,000-22,000 cfs. Everglades Agricultural Area 900 mi 2 - Average water supply demand ~350,000 ac - ft, ~ 1.2M ac - ft are discharged for flood protection. Water Conservation Areas 1,370 mi 2, Average inflows ~1.4M ac - ft, effective storage ~ 1.9M ac - ft. WCA-3A Inflow 26,000 cfs > Outflow 9,000-35,000 cfs. Lower East Coast ~ 1.3M ac - ft groundwater seepage, ~280,000 ac - ft for water supply deliveries, coastal discharges ~3.2M ac - ft for flood protection. Everglades National Park 1.5 M acres Average inflows 1.0M ac - ft, with outflows of ~ 1.9M ac - ft (sign. seepage losses). Avg. Annual Flows in 1,000 ac - ft/yr Source: SFWMM 2010 Baseline, SFWMD, The C&SF Project has major design and conveyance limitations.

5 Critical Restoration Components Enough water storage capacity to support healthy estuaries and the return of Everglades sheetflow, while meeting other water demands. Primary Focus of CERP, water assurances. Delivering water to the natural system in ways that resemble historic flow patterns (volume, depth, velocity, direction, distribution, and timing). Focus of Foundation Projects (Kiss., Modified Water Deliveries, C-111South Dade). Barriers to eastward seepage that can support higher water levels in the Everglades, and maintain flood protection in developed areas. Focus of East Coast Buffer & Water Preserve Areas. Securing water quality conditions compatible with restoration of a naturally nutrient limited ecosystem, particularly related to phosphorus. Focus of Consent Decree, EFA/Phosphorus Rule, EPAAmended Determination. Retention and expansion of the full range of critical wetland and estuarine habitats useful for a restored ecosystem. Focus of Endangered Species Act, Migratory Bird Treaty Act. Source: National Research Council/Co mmittee on Independent Scientific Review of Everglades Restoration Progress, First Biennial Re view, 2006.

6 Potential Benefits of Reducing Northern Estuary Regulatory Releases via Increased Everglades Inflows Enhanced Everglades Inflows = Reduced Estuarine Harm Current Enhanced 40% Reduction 80% Reduction Preliminary findings requiring more detailed analyses.

7 Estimated Water Storage Required vs Provided by Approved Projects Source: Options to Reduce High Volume Freshwater Flows to the St. Lucie and Caloosahatchee Estuaries and Move More Water from Lake Okeechobee to the Southern Everglades, U. FL March 2015.

8 Percent Achievement in Reducing Harmful Discharges to the Northern Estuaries and Beneficial Flows to the Everglades Red Stars Expected Performance after implementing Restoration Strategies and CEPP. Green Stars Desired Performance requiring substantial additional water storage north/south of Lake Okeechobee. Source: Options to Reduce High Volume Freshwater Flows to the St. Lucie and Caloosahatchee Estuaries and Move More Water from Lake Okeechobee to the Southern Everglades, U. FL March 2015.

9 Conditions in 2011 for Phosphorus Entering the Everglades STAs = 45,500 effective acres, with 11,400 acres under construction. Flow Weighted Mean Total Phosphorus Outflow Concentrations: East (STA1E & STA 1W) = 34.6 ppb Central (STA2 & STA3/4) = 29.4 ppb West (STA5 & STA 6) = 29.7 ppb 1.4M ac-ft Current Conditions (Scenario 1) Current Conditions = Scenario 1 in the EPA Amended Determination. Design target for STA outflow TP conc. is 11.5 ppb, expressed as a long-term (40 year) flow-weighted mean. Annual limit for STA outflow TP conc. is 18 ppb. Preliminary findings requiring more detailed analyses. Approximate Model Uncertainty +/ - 15% conc. of TP

10 1.4M ac-ft Improved Conditions for Phosphorus Entering the Everglades (EPA/AD) STAs = 76,100 effective acres, with 7,000 acres as a Flow Equalization Basin. Flow Weighted Mean Total Phosphorus Outflow Concentrations: East (STA1E & STA 1W) = 11.4 ppb Central (STA2 & STA3/4) = 11.5 ppb West (STA5 & STA 6) = 11.4 ppb A - 2 and southern C Annex not required for EPA/AD.. Improved Conditions (Scenario 7) Improved Conditions = Scenario 7 in the EPAAmended Determination. Design target for STA outflow TP conc. is 11.5 ppb, expressed as a long-term (40 year) flow-weighted mean. Annual limit for STA outflow TP conc. is 18 ppb. Preliminary designs requiring more detailed analyses. Approximate DMSTA Model Uncertainty +/ - 15% of TP conc.

11 1.6M ac-ft Preliminary designs requiring more detailed analyses. Approximate DMSTA Model Uncertainty +/ - 15% of TP conc. Integrating Water Flow & Water Quality Improvements (DOI, draft 2011) The WCA 3 Decomp. Phase 1 project is in planning, but restoring sheetflow into northern WCA-3A requires increased volumes of clean water (ability to limit flows). Utilizing A-2 and the southern C-139 Annex lands as STAs or FEBs could provide expanded storage/treatment, and maintain the 11.5 FWM Total Phosphorus Outflow Target Concentrations in the EPAAmended Determination. Preliminary Evaluations suggest that approximately 150, ,000 ac-ft of new clean water could be delivered to the EPA. Annual Flow Volumes (Millions ac-ft)

12 2.0M ac-ft Preliminary designs requiring more detailed analyses. Approximate DMSTA Model Uncertainty +/ - 15% of TP conc. Integrating Water Flow & Water Quality Improvements (DOI, draft 2011) The WCA 3 Decomp. Phase 1 project is in planning, but restoring sheetflow into northern WCA-3A requires increased volumes of clean water (ability to limit flows). Utilizing A-2, the C-139 Annex lands, and an upstream EAA reservoir/feb could provide expanded storage/treatment, and maintain the 11.5 FWM Total Phosphorus Outflow Target Concentrations in the EPAAmended Determination. Preliminary Evaluations suggest that approximately 450, ,000 ac-ft of new clean water could be delivered to the EPA. Annual Flow Volumes (Millions ac-ft)