Water managers will throw open the floodgates around Lake Okeechobee Friday as they race to stop the rising lake in a region soaked by this winter’s El Niño.
With rainfall runoff now coming into the lake three times faster than it can be pumped out, the U.S. Army Corps of Engineers said it would increase the amount dumped into the St. Lucie and Caloosahatchee rivers from the most allowed by regulation to as much as possible — more than 10 billion gallons of dirty water every day.
The Corps said it was acting under emergency authority to reduce pressure on the lake’s aging Herbert Hoover dike.
“Our main purpose right now is public safety,” said Jim Jeffords, Operations Division Chief for the Corps’ Jacksonville office. “We’re really just one small event away from being at a record event.”
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The lake began rising rapidly after a record January rainfall. So far, increased releases have slowed but not stopped the rise of water, which on Thursday hovered at 16.25 feet, about 2.5 feet short of an all-time high set in 1947.
The Corps could begin sending as much as 4.9 billion gallons of water — about 7,400 Olympic swimming pools — daily into the St. Lucie river on the east coast. Even more would be released into the larger Caloosahatchee on the west coast. Such massive dumps in the past have caused widespread damage to the estuaries at the mouths of the rivers, where seagrass beds and oysters can’t tolerate such high amounts of freshwater. Already, a brown plume has spread off the coast of Sanibel. The last time so much water was released, in 2013 and following a 1998 El Niño, fish kills and dead sea life lasted for months, infuriating local communities.
Inspectors are also keeping an eye on the aging dike’s southern rim, which has suffered from leaks and small boils. Following Hurricane Katrina, the Corps sped up repair work but is still about two to three years away from changing lake operations based on those improvements, said spokesman John Campbell.
On Monday, inspectors made a full survey of the 143-mile-long dike and found clear water leaking from four areas between Port Myaca and Moore Haven in areas where seeps had already been noted. Another area had standing water, and two more spots had standing water or wet soil. If the lake were to reach 17 feet, inspectors would begin inspecting the dike twice weekly. At 18 feet, they would conduct daily surveys, Jeffords said.
Our most important thing is the integrity of the [Herbert Hoover Dike] right now.
U.S. Army Corps of Engineers Jacksonville Division Operations Chief Jim Jeffords
“Our most important thing is the integrity of the [Herbert Hoover Dike] right now,” he said.
Since November, the region has been hit hard by winter rains in what is supposed to be South Florida’s dry season. The South Florida Water Managment District moved about four inches off the lake since November, said spokesman Randy Smith. The Corps also began releasing lake water into the rivers at a slower rate than it’s now planning. But neither step could keep up with rainfall between 200 and 300 percent above normal in counties surrounding the lake.
Saturated conditions have also filled up three water conservation areas south of the lake that could be used to hold water. Runoff from local areas has also slowed releases from the lake, which cannot exceed the capacity of local canals and flood control structures.
Last week, the water management district took the rare step of pumping polluted water from the south, dominated by sprawling sugarcane fields, back into the lake. The pumping angered environmentalists who have long fought to clean up high levels of phosphorus that can damage Everglades marshes. That backpumping added about an inch to the lake and lasted four days.
While staff have been warning against heavy rain putting the lake perilously high since the fall, Jeffords said the Corps’ operating permit — a deal struck in 2008 to balance flood control risk with the damage to the rivers — does now allow releases to begin until elevated levels are reached.
“As the lake starts increasing,” he said, “the discharges start.”