The Southwest Florida Water Management District is working with the City of Anna Maria on a project that will reduce flooding and improve water quality.
The Gladiolus/North Shore Basin Drainage Improvements project involves installing approximately 3,200-linear feet of 1-foot deep dry retention swales, approximately 700-linear feet of high density polyethylene and reinforced concrete pipe, six inlet control structures and a baffle structure at each of the four basin outfall locations within the Gladiolus/North Shore drainage basin. The basin, which is approximately 27 acres, is located on the north end of the city of Anna Maria.
The retention swales are expected to treat approximately 12,800 cubic feet of stormwater runoff through percolation and evaporation and the baffles are expected to provide treatment through sedimentation and skimming, thus reducing the overall pollutant loadings to the man-made canal system, Anna Maria Sound, Sarasota Bay and Tampa Bay. Both Sarasota Bay and Tampa Bay are classified as Surface Water Improvement and Management (SWIM) program priority water bodies and National Estuary Program water bodies.
The swales will also increase the storage and conveyance capacity of the city’s existing drainage system, which will reduce flooding. Additional storage is needed because the basin outfall structures are influenced by tidal conditions. The additional storage will help contain stormwater runoff during high tide conditions.
This project is a cooperatively funded effort between the City of Anna Maria and the Districts Manasota Basin Board. The total estimated cost of this project is $270,000, with each partner contributing up to $135,000.