Projects to create STAs and additional water storage
Restoration Strategies for Clean Water for the Everglades
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.
With construction complete, water began flowing into the A‑1 Flow Equalization Basin for the first time in August 2015.
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.
- Notice of DEP Action on STA Watershed Permits – Sept. 11, 2012 [PDF]
- DEP: STA Watershed Permits and Supporting Documentation
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 2017, these constructed wetlands treated more than 1.1 million acre-feet of water bound for the Everglades, reducing phosphorus loads by 84 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.
What is phosphorus?
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, with completion of all projects set for 2025. Work is already underway on several components for the plan's first two phases. Projects in these two phases are scheduled to be finished by 2016 and 2018, respectively.
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 stormwater flowing into the Refuge and other parts of the greater Everglades. The 6,500-acre expansion of STA-1 West, which will take place in two phases, will double its effective treatment area and further reduce phosphorus concentrations.
- Project Status: Construction of Phase 1 ongoing
- Expected Construction Completion Date: December 2018 (Phase 1)
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 attenuates 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 also contains emergent vegetation to help reduce phosphorus concentrations before moving water to the STAs.
- Project Status: Operational testing and monitoring phase
- Construction Completion Date: November 2015
- FYI: A-1 Flow Equalization Basin [PDF]
- Video: Initial Filling of the A-1 Flow Equalization Basin
L-8 Flow Equalization Basin
Building on a strategically located 950-acre former rock mine, this deep below-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 stormwater to STA-1 East and STA-1 West to improve their performance and to provide interim benefits for restoration purposes. When the STA-1 West expansion is operational, the L-8 FEB will transition to primarily storing stormwater runoff and delivering flows to optimize the treatment performance of STA-1 East and STA-1 West.
L-8 Divide Structure (G-541)
G-541 is 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 water into the L-8 FEB for storage and, when needed, assist in directing FEB outflows south to STA-1 East and STA-1 West for treatment. G-541 is designed to function within the current operational criteria for the L-8 canal to maintain flood control for the basin.
- Project Status: Operational
- Construction Completion Date: July 2016
S-5AS 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 modifications and upgrades to the structure are required to ensure more efficient operations.
- Project Status: Operational
- Construction Completion Date: May 2016
S-375 Structure Expansion (G-716)
The new G-716 structure expands 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 direct stormwater runoff to the L-8 FEB for storage prior to being redirected to STA-1 East and/or STA-1 West for treatment.
- Project Status: Operational
- Construction Completion Date: April 2017
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.