Lake Okeechobee Water Release Could Curb Toxic Algae Bloom

The Army Corps of Engineers announced a plan to begin small releases of water from a bloated Lake Okeechobee in an effort curb the threat of a toxic algae bloom over the summer.

Audubon Florida scientist Paul Gray told The Palm Beach Post that the unpopular decision to release water to the St. Lucie Estuary may help South Florida and the Treasure Coast narrowly escape a cyanobacteria algal bloom this summer.

But there are no guarantees it will work and no one is happy with the decision, Gray said.

“The lake is too deep. It’s actually way too deep,” Gray said. “Everyone wants the lake lower, but no one wants to take any water.”

Submerged grasses, which are vital to the lake's ecosystem, suffer when the lake is too high. The high water levels are also a concern for the Herbert Hoover Dike, the newspaper reported.

The St. Lucie estuary is not a natural outlet and releasing the lake's water is deadly to brackish water-loving flora. It can also promote toxic algae blooms by seeding the water and diluting salinity levels, the Post reported.

While the South Florida Water Management District supported the decision to release water to the St. Lucie Estuary, spokesman Randy Smith said they will closely monitor salinity levels.

With rainy season approaching in May, South Florida is still soggy from Tropical Storm Eta last year. Gray told the newspaper it was “time to start releasing water everywhere we can.”

On Wednesday, Lake Okeechobee stood at 15.13 feet (4.6 meters) above sea level. Current guidelines call for the lake to be maintained at between 12.5 (3.7 meters) and 15.5 feet (4.7 meters) above sea level.

“Recession rates we had anticipated in February did not materialize,” said Col. Andrew Kelly, commander of the Jacksonville District Corps. “We are still tracking that the lake is going to be higher than we want at the start of rainy season which directly equates to a higher risk of high-volume releases in the fall — and nobody wants that.”

A tropical system can easily push the lake several feet higher, officials said. In 2017, rainfall from Hurricane Irma added 3 feet (1 meter) to the lake in a month. It peaked at at 12-year high of 17.16 feet (5.2 meters). The next summer, algae-laden lake discharges led to a widespread bloom on the St. Lucie and Caloosahatchee.

Gray said he's more comfortable that increased releases now will lower the lake to 12.5 (3.7 meters) to 13 feet (3.9 meters) ahead of rainy season.

“The challenge for the agencies is to get the largest releases possible without causing short-term disasters to those systems getting the discharges,” Gray said. “Letting the water out now means taking water that is bad for you, but at least it won’t have harmful algal blooms in it.”

Mark Perry, executive director of the Florida Oceanographic Society in Stuart, told the Post he wants more water to be released south of the lake.

“If it’s not doing much to lower the lake, is it worth the damage to the estuary?” Perry said. “We already have a loss of sea grass, a loss of oysters — it’s really a big impact for the estuary and not much impact for the lake.”

Water managers have said that areas south of the lake from the Loxahatchee National Wildlife Refuge west of Boynton Beach to the Tamiami Trail have suffered harmful flooding for months, overwhelming storm water treatment areas that use plants to remove phosphorus from water before sending it to the Everglades.

“The storm water treatment areas are the heart of everything. If they go wrong, everything goes wrong,” said South Florida Water Management District board member Jacqui Thurlow-Lippisch in a February meeting.

The Army Corps makes weekly decisions on lake levels, and Perry hopes the water releases end before the April oyster spawning.

“They are saying they are releasing water now so there won’t be harmful blooms later,” Perry said. “But our contention is there’s nothing preventing the blooms from still happening if we get more rain and the lake is still too high.”