The State of Florida and the U.S. Environmental Protection Agency reached a consensus on new strategies for improving water quality in America's Everglades. Based on months of scientific and technical discussions, these strategies will expand water quality improvement projects to achieve the phosphorus water quality standard established for the Everglades.
Under these strategies, the South Florida Water Management District is implementing a technical plan to complete several projects that will create more than 6,500 acres of new stormwater treatment areas (STAs) and 116,000 acre-feet of additional water storage through construction of flow equalization basins (FEBs). Flow equalization basins provide a more steady flow of water to the STAs, helping to maintain desired water levels needed to achieve optimal water quality treatment performance.
A flow equalization basin (FEB) is a constructed storage feature used to capture and store peak stormwater flows. Water managers can move water from FEBs into STAs at a steady rate to optimize STA performance and achieve water quality improvement targets.
The strategies also include additional source controls – where pollution is reduced at the source – in areas of the eastern Everglades where phosphorus levels in stormwater runoff have been historically higher. In addition, a robust science plan will ensure continued research and monitoring to improve and optimize the performance of water quality treatment technologies.
Produced for the April 2, 2015, WRAC meeting, this video provides an aerial tour of construction progress being made on the L-8 FEB.
The technical plan is part of a revised National Pollutant Discharge Elimination System (NPDES) permit issued by the Florida Department of Environmental Protection and approved by the U.S. Environmental Protection Agency for operation of the District's network of Stormwater Treatment Areas south of Lake Okeechobee. The NPDES permit – along with a new state-issued Everglades Forever Act permit – establishes stringent phosphorus limits for water discharged into the Everglades.
Construction of new treatment and storage projects identified in the technical plan will build on the State's significant progress to protect the Everglades. To date, the State of Florida has invested more than $1.8 billion toward improving water quality in the "River of Grass."
Key water quality improvements to date include:
Operation of five Everglades STAs with an effective treatment area of 57,000 acres. In Water Year 2015, these constructed wetlands treated more than 1.4 million acre-feet of water bound for the Everglades, reducing phosphorus loads by 83 percent.
Construction of nearly 12,000 acres of STA expansions, which was completed in 2012.
Implementation of improved farming methods, known as Best Management Practices (BMPs), on 470,000 acres of agricultural lands south of Lake Okeechobee. Over the BMP program's 20-year history in the Everglades Agricultural Area, the average phosphorus reduction is more than twice the amount required by Florida's Everglades Forever Act.
Although it is a vital nutrient in all natural systems, phosphorus is also a fertilizer component. It flows across the landscape in stormwater runoff (urban and agriculture), harming natural areas by promoting algae growth and an overabundance of non-native plants, crowding out natural vegetation and disrupting food sources and habitats used by native wildlife. The Everglades is naturally a low-nutrient system. Even small amounts of additional nutrients can upset the ecological balance needed by the native plants and animals in the historic "River of Grass."
Design and construction of the treatment and storage projects in the Restoration Strategies Regional Water Quality Plan will take place in three phases over a 12-year timeframe, with completion of all projects set for 2025. Work is already under way on several components for the plan's first two phases, which are scheduled to be finished by 2016 and 2018, respectively.
A-1 Flow Equalization Basin
With a capacity of 60,000 acre-feet, this project is the largest of three flow equalization basins in the Restoration Strategies plan. The A-1 FEB will attenuate peak stormwater flows, temporarily storing water so it can be delivered at a steady rate to STA-2 and STA-3/4 to improve their performance. As a shallow FEB, the A-1 will also contain emergent vegetation to help reduce phosphorus concentrations before moving water to the STAs.
Building on a strategically located 950-acre former rock mine, this deep-ground reservoir is capable of storing 45,000 acre-feet of water. Initially, this project will function as a multipurpose FEB to capture, store and deliver water to STA-1 East, STA-1 West and the Loxahatchee River and for other restoration purposes. When the STA-1 West expansion is completed and in-basin storage for the Loxahatchee River comes online, the L-8 FEB will transition to primarily delivering consistent flows needed to optimize performance of STA-1 East and STA-1 West as part of the Restoration Strategies Regional Water Quality Plan.
Project Status: Construction ongoing, including inflow works and outflow pump station
Also known as the G-541 structure, this project will be a fully automated water control structure located within the L-8 canal, just east of the L-8 FEB. The structure will assist the movement of stormwater into the L-8 FEB for storage and, when needed, assist in directing water from the flow equalization basin south to STA-1 East and STA-1 West. G-541 will be designed to function within the current operational criteria for the L-8 canal to maintain flood control for the basin.
Project Status: Under construction
Expected Completion Date: September 2018
S-5AS Divide Structure Modifications
Implementation of projects in the Restoration Strategies plan will increase the use of the existing S-5AS structure to direct stormwater runoff north to the L-8 FEB for storage. As a result, some upgrades and repairs to the structure are required to ensure more efficient operations and increased use at higher stages and flow rates.
Project Status: Under construction
Expected Completion Date: September 2016
S-375 Structure Expansion
A new structure, known as the G-716, will be constructed to expand the capacity of the existing S-375 structure, located within STA-1 East. During high flow events in the C-51 West Basin or when STA-1 East is already receiving optimal flows, S-375 and G-716 will divert water to the L-8 FEB for storage prior to being redirected to the STAs for treatment.
Project Status: In detailed design
Expected Completion Date: December 2018
Stormwater Treatment Area 1 West Expansion
Located immediately northwest of the Arthur R. Marshall Loxahatchee National Wildlife Refuge, STA-1 West removes excess phosphorus and other nutrients from water flowing into the refuge and other parts of the greater Everglades. The expansion of the STA will double its effective treatment area, further reducing phosphorus concentrations. The expansion will take place in two phases, with approximately 6,500 total acres of new treatment area.
As part of the Restoration Strategies Regional Water Quality Plan, the District proposes to build on the existing BMP Regulatory Program by focusing on areas and projects with the greatest potential to further improve water quality. The District's goal is to design water quality improvement projects in strategic onsite locations or through sub-regional source control projects in series with on-site BMPs to further reduce total phosphorus loads to the STAs.
East Beach Water Control District Project
The East Beach Water Control District (EBWCD) in Belle Glade volunteered in June 2013 to participate in a three-year cooperative agreement with the SFWMD on a sub-regional canal cleaning implementation and demonstration project within the S-5A sub-basin. This interest is based on promising preliminary results of UF/IFAS research on a comprehensive canal management program at a research plot level. This type of demonstration has not been evaluated on a sub-regional scale.
The EBWCD project includes evaluation of data associated with existing water quality, floating aquatic vegetation and canal sediment conditions under current practices, in contrast with feasible comprehensive canal management practices. The activities funded by this project are above and beyond existing BMP plan regulatory requirements.