The U.S. Army Corps of Engineers begins enhanced discharges from Lake Okeechobee on Saturday.
The freshwater releases into saltwater estuaries are aimed at reducing the level of the lake ahead of the rainy season.
Lake Okeechobee is about two feet higher (16.3 feet) than what officials prefer to keep it at this time of the year.
Water managers estimate that the majority of the discharges will go into the Caloosahatchee River, to the west of the Lake, but 1,800 cubic feet per second will be released into the St. Lucie River through the St. Lucie Lock and Dam. Some releases will also be made into the Lake Worth Lagoon through the C-51 Canal.
The discharges bring concerns about toxic algae getting into local waterways as has happened in the past.
Congressman Brian Mast, whose been fighting the discharges for years, says he is demanding answers from the Army Corps. He's concerned about the current management of the lake, which keeps Lake Okeechobee artificially high during dry periods to benefit the sugar industry, which comes Mast says at the expense of all other Floridians.