WEATHER

Harmful Lake O discharges begin; Lake Worth Lagoon not direct target but will be affected

Kimberly Miller
Palm Beach Post
Proposed Tarpon Cove islands near the El Cid neighborhood are designed to be similar to these South Cove islands built in the Lake Worth Lagoon near downtown in 2010. (Tony Doris / The Palm Beach Post)

Harmful discharges of Lake Okeechobee water to the northern estuaries began Wednesday and will have an indirect effect on the Lake Worth Lagoon

While the St. Lucie and Caloosahatchee estuaries will get a direct freshwater spew of nutrient-loaded water from the swollen lake, a third spigot will run to holding areas that normally take Palm Beach County basin runoff. 

That means the runoff, mostly from rainfall, will flow instead through the C-51 canal into the Lake Worth Lagoon. It can be a damaging onslaught of freshwater and silt into the brackish estuary that struggles to maintain its sea grass and oyster populations. 

More:They tried to fix the Lake Worth Lagoon with a muck trap, then they forgot about it

The Army Corps of Engineers announced the releases Wednesday. The last release to the northern estuaries was in March 2019. 

Water control gate at the C-51 canal near the Intracoastal Waterway, between Lake Worth and West Palm Beach. (Howard Goodman / Palm Beach Post)

But with Lake Okeechobee at 16.21 feet above sea level and the hurricane season still active, officials said they needed to stall the lake's rise. In the recent past, the Corps has tried to keep the lake between 12.5 feet and 15.5 feet above sea level to protect the integrity of the Herbert Hoover Dike while maintaining water supply for the dry season. 

"We've been very deliberate about not releasing up to this point, but we can't wait any longer," said Col. Andrew Kelly, commander of the Corps' Jacksonville District. "My commitment is to execute the releases we need for the shortest duration possible." 

>>MORE: Habitat restoration project to boost Lake Worth Lagoon 

Kelly said the lake is rising because more water is coming in from the north than can be sent south because water conservation areas are already flooded from the rainy season. Flows south are also blocked by structures, such as the Tamiami Trail. 

While 8,000 to 10,000 cubic feet per second (or cfs) of water has been flowing into the lake from the north, just 800 cfs has been leaving the lake. 

As of Wednesday, the Caloosahatchee River will receive 4,000 cfs of Lake Okeechobee water. The St. Lucie River will receive 1,800 cfs.

C-51 Canal (looking west) near Stormwater Treatment Area 1 East Thursday, October 12, 2017. (Bruce R. Bennett / The Palm Beach Post)

The third new release will be through the L8 canal into a flow equalization basin and stormwater treatment area in Palm Beach County. Both will get 500 cfs. Flow equalization basins can act as mini reservoirs for excess water. Stormwater treatment areas are where plants help cleanse the water of harmful nutrients. 

"The last time the estuaries got blasted with Lake Okeechobee discharges during the rainy season, guacamole-green water tainted both coasts — drawing international attention to Florida for all the wrong reasons," said Friends of the Everglades Executive Director Eve Samples in a statement. "This is not going to be pretty." 

The Caloosahatchee and St. Lucie suffered devastating toxic algae blooms most recently in 2016 and 2018. The Lake Worth Lagoon is not immune, also suffering an algae bloom in 2016. 

More:Why 240 bright pink wooden cards were dumped in the Lake Worth Lagoon

While Lake Okeechobee water can seed algae growth in the estuaries, it also dilutes the brackish waters where saline would normally discourage algae blooms.

Kelly said he hopes the algae will be stymied by the shorter days and cooler temperatures of fall. 

"Algae tends to prefer hot and still water," Kelly said. "It's a little cooler, so the conditions are better this time of year than mid-summer." 

Kmiller@pbpost.com

@Kmillerweather