|
The lake's level peaked above 18 feet in October 1999, a level U.S. Army Corps of Engineers feared would cause the dike surrounding the lake to fail. In response, water managers flung open the spillways leading into the Caloosahatchee and St. Lucie rivers.
The district released about 2 million gallons of lake water per minute into the Caloosahatchee over roughly a month.
What worries some environmentalists and others along the Southwest Florida coast is the appearance in recent weeks of another mass of black water that formed off Sanibel Island near where the Caloosahatchee River empties into the Gulf of Mexico.
By June 2000, the lake was lowered to 13 feet.
The district and Army Corps were forced to re-examine their water-management policies for the lake after public outcry arose over algae blooms and fish kills in the Caloosahatchee.
Today, water managers try to keep the lake between 13 1/2 and 15 1/2 feet to avoid major releases such as those in 2000, said Karen Estock, head of the Army Corps South Florida Operations office in Clewiston.
Water management officials also use so-called "pulse releases," 10-day-long periods in which they keep spillways open. And releases don't happen unless scientists, local and state politicians and concerned citizen groups give their blessing.
"That's always our goal— let people know what we're going to do, get some feedback and them make our decision," Estock said. "It's science and politics."
There have been two recent "pulse releases." One ran from July 15 to July 25. Another began Aug. 1 and will continue until Aug. 10.
In both cases, the decision to let the water out of the lake came after its level jumped above 14 1/2 feet. Water management officials try to keep levels lower during the rainy season, Estock said.
The release's intensity reached a peak a week ago, when nearly 3,500 cubic feet per second of water rushed into the Caloosahatchee through the Moore Haven lock, where the river meets Lake Okeechobee.
However, the lake's level has increased slightly due to rainfall.
Lake water quality
The amount of fresh water directed down the Caloosahatchee is a problem, environmentalists and the state agree, and most people also agree it's a combination of lake releases, farm and urban runoff.
What worries people like David Guest, an attorney for the environmental law firm Earth Justice, is what's in the water.
Lake Okeechobee is more than just a place to fish. It's also where agricultural interests around the lake pump excess water to keep farm fields dry. What comes with the water is loads of nitrogen and, to a lesser degree, phosphorus, according to the water district's own reports.
Together, they're food for a host of organisms that, though generally harmless, can choke waterways when they can grow out of control.
Guest said the water backpumped from farms is bad for creatures in the Caloosahatchee and could just as well be bad for the Gulf.
"When you have algae or maybe the black tide and when that arrives and finds nutrient-rich water, is it a surprise that it grows out of control?" he asked.
Porter, whose team recently identified a new disease decimating elkhorn coral in waters up and down the Keys, said the black water is a mystery and that research and monitoring needs to go on.
"I'm deeply concerned by that event," he said, "as much because I don't know what it means as I know what it did. I don't think anyone knew how important this was because it had never happened before."
Click here for further Naples Daily News coverage of the black water issue.
|
