Posted January 30, 2019
Spring Lake, a polluted body of water between 68th and 70th streets in Holmes Beach, was determined to be brackish by the Southwest Florida Water Management District. City officials will decide next how to clean and aerate the lake. Islander Photo: ChrisAnn Silver Esformes
Questions about Spring Lake have been answered.
And action will be taken.
The lake, a saltwater-fed lake between 68th and 70th streets — has been undergoing review to determine the best way to remove the “depth of muck and sewage that has settled to the bottom,” according to city engineer Lynn Burnett.
She met with representatives from the Southwest Florida Water Management District, who provided historical documents indicating the lake originally was a mangrove-heavy, upper wetland area before it was excavated to create two lakes, joined by a channel, stocked with fish and connected to outfall pipes.
Burnett said the work was executed prior to Swiftmud assuming jurisdiction over the brackish lake.
“It is neither a freshwater system nor a saltwater system,” she said. “They deemed it as a brackish system,” adding that Swiftmud said the lake will “always be a brackish system.”
If the city wants to clean up Spring Lake and provide the best quality of water, the lake must be dredged, and an aeration system installed to preserve the saltwater-freshwater balance.
According to a bathymetric survey, the lowest depth is 7 feet, as compared to historical records from the time the lake was excavated, which state the depth was 10 feet.
“So there is 3 feet of muck at the bottom of Spring Lake, on average,” according to Burnett, who said core samples were taken to determine the level of pollution. Once those results are received, she recommends approaching Manatee County for assistance with dredging and disposing of the sludge.
“There’s a discussion that needs to happen with Manatee County after we know the actual composition,” Burnett said.
Additionally, two WaStop tidal regulating valves installed in 2017 in the lake as part of stormwater improvements must stay in place, Burnett recommended.
“Removing those would subject property owners to flooding, and (Swiftmud) would not support that request,” she said.
Removal of the valves would require a permit and put the city in jeopardy of losing a stormwater grant.
The next city commission meeting will be at 6 p.m. Tuesday, Feb. 5, at city hall, 5801 Marina Drive, with a work session to follow.
Source: The Anna Maria Islander