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Corps begins Lake O releases to the Caloosahatchee

By Staff | Jul 28, 2009

With the recent rise in Lake Okeechobee levels, the U.S. Army Corps of Engineers began four days of releases to the Caloosahatchee and St. Lucie estuaries on July 23, followed by eight days of pulse releases that began on July 27.

The Corps, anticipating more rain to come this summer, decided to release water to spare the estuaries later damaging, high flow, releases, to help maintain lake health and to alleviate pressure on the Herbert Hoover Dike.

Until a way to flow water south out of the lake is finalized, releases to the east and west are the options water managers use for lowering lake levels. Farmers and other heavy water users, fearing a return of drought, were angered and felt the Corps should have waited longer before deciding to make releases.

Following the rain-heavy 2004 and 2005 hurricane seasons, massive releases from Lake Okeechobee, sometimes over 8,000 cfs (cubic feet per second) caused major harm to the Caloosahatchee and St. Lucie estuaries, with fish kills, oyster, clam and blue crab kills and massive harmful algal blooms.

The polluted, turbid lake water caused large seagrass die-offs because sunlight could not penetrate the dark brown water. Seagrasses and other submerged aquatic vegetation provide critical nursery habitat.

According to the Army Corps, the eight-day pulse releases will reach up to 2,800 cfs for the Caloosahatchee and 950 cfs for the St. Lucie (which has a smaller estuary). Rather than flowing water steadily at 2,800 cfs, the amount of water in a pulse release varies from high to low in an attempt to minimize damage and mimic natural storm events.

SCCF and other environmental groups continue working to find ways to increase water storage capacity and to move water south into the Everglades. Without increased storage and a flow-way south, the estuaries will continue to see periods of too much or too little freshwater.