Water Quality Improves in Everglades
South Florida Water Management District
December 14, 2017
The recently completed L-8 Flow Equalization Basin is a key component of Gov. Rick Scott’s Restoration Strategies Plan that is maximizing the restoration of Everglades water quality. Click on the image to see a larger version.
West Palm Beach, FL – Thanks to more than two decades of collaborative efforts by the South Florida Water Management District (SFWMD) and Florida Department of Environmental Protection, water quality in the Everglades is another year older and another year better. In Water Year 2017, the District’s network of constructed treatment wetlands, known as Stormwater Treatment Areas (STAs), treated water to an average of 15 parts per billion (ppb) of phosphorus, the best performance on record.
According to water quality data presented last week by the District at the Water Resources Analysis Coalition public forum, one of the few remaining “impacted” monitoring stations with levels of phosphorus greater than 10 ppb successfully transitioned over into the classification of being “unimpacted.” Monitoring station data verifies the area receiving treated water from STA-1 East located in the northern portion of the Arthur R. Marshall Loxahatchee National Wildlife Refuge now meets state water quality standards.
“The water quality targets needed for America’s Everglades to thrive are being met, and our performance keeps improving each year thanks in large part to the guidance laid out in Gov. Scott’s Restoration Strategies Plan,” said SFWMD Governing Board Vice Chairman Jim Moran. “With most of the plan’s works already completed and the rest underway, we are within sight of the water quality finish line.”
Before the Florida Legislature passed the Everglades Forever Act in 1994, water flowing south out of the Everglades Agricultural Area (EAA) contained an average of 173 ppb of phosphorus. Thanks to the District’s STAs, phosphorus levels in this Everglades-bound water have been reduced on average over the last five years to 19 ppb. This has resulted in a dramatic drop in phosphorus levels within the Water Conservation Areas.
Through April 2017, the STA network and improved farming techniques known as Best Management Practices (BMPs) have combined to remove or prevent approximately 5,500 metric tons of phosphorus from entering the Everglades. Tests show at least 90 percent of the Everglades now meets ultra-clean water quality standards for levels of phosphorus at 10 ppb or less required by state law. The average total phosphorus concentration of water in Everglades National Park is reported to be approximately 4 ppb.
Best Management Practices
BMPs are improved farming techniques in the 470,000-acre EAA and are the first step to clean water flowing south. Over the history of the BMP program, phosphorus levels in water leaving the EAA dropped by an annual average of 55 percent compared to initial conditions. This is more than twice the improvement required under the Everglades Forever Act. The BMP program has prevented more than 3,000 metric tons of phosphorus from entering the Everglades ecosystem.
Examples of BMPs include refined stormwater management practices, on-farm erosion controls and more precise fertilizer application methods. These and other management practices reduce the amount of phosphorus discharged from agricultural areas.
Stormwater Treatment Areas
Before water reaches the Everglades, it receives additional treatment using “green technology” in the STAs. Currently, with 57,000 acres of effective treatment area, the STAs are filled with a mixture of emergent aquatic vegetation, such as cattail, bulrush and spike rush, and submerged aquatic vegetation, such as hydrilla and southern naiad. These wetland plants absorb phosphorus for their own growth and store it in their roots, stems and leaves. Even after they die, sediments in the STAs retain phosphorus from the decaying plant matter. Part of Restoration Strategies will expand the total amount of STAs treating Everglades water by 6,500 acres.
Since 1994, the network of five STAs south of Lake Okeechobee has treated approximately 18 million acre-feet of water. From that water, the STAs retained approximately 2,329 metric tons of phosphorus that would have otherwise entered the Everglades. To date, the STAs have retained more than 80 percent of the phosphorus from water flowing through the treatment cells.
For More Information
- Water Quality Improvement – https://tinyurl.com/yamha7do
- BMPs and Source Controls – https://tinyurl.com/y838r96a
- Restoration Strategies for Clean Water for the Everglades – https://www.sfwmd.gov/our-work/restoration-strategies
- South Florida Environmental Report – https://www.sfwmd.gov/science-data/scientific-publications-sfer
Thank you Gene McAvoy for sharing this post. Gene is the Vice President National Association of County Agricultural Agents County Extension Director Regional Vegetable Agent IV UF/IFAS Hendry County Extension
PO Box 68
LaBelle, Florida 33935