WEST PALM BEACH, FL, July 11, 2008 -- Construction of a water control weir in the Kissimmee River, the largest single structure ever built by the South Florida Water Management District (SFWMD), is nearing completion. The weir is one of four emergency improvement projects undertaken this year to protect major water control structures when Lake Okeechobee experiences very low water levels.
South Florida's extended, record-breaking water shortage could have resulted in instability at four vital water control structures (S-65E, S-71, S-72 and S-84) when a significant difference occurred between water levels immediately upstream and downstream of these structures. District experts determined that this would most likely occur if the tailwater (downstream) level at Lake Okeechobee dipped below 10.0 feet -- but water levels become high upstream in the Kissimmee River and Lake Istokpoga basin, which feed into the lake.
Work to relieve those pressures continues at the weir construction site, located almost one mile downstream of the S-65E water control structure on the Kissimmee River. The weir will provide stability for both the S-65E and S-84 structures. Improvements protecting the S-71 and S-72 structures have been completed.
"These structures were subjected to unusual conditions during the prolonged water shortage, especially those near Lake Okeechobee and its record low water levels," said George Horne, SFWMD Deputy Executive Director for Operations & Maintenance. "The construction projects have restored stability to four at-risk structures, assuring that our flood control system can operate safely and effectively under even extreme conditions."
The new weir (C-38) is the largest of the improvement projects. Building it required 2.5 million pounds of 70-foot-long steel sheets and 110 million pounds of rip rap stone. On Saturday and Sunday, workers will spend 18 hours pouring 2,800 cubic yards of concrete underwater in the center portion of the submerged structure.
When the weir is complete, it will be able to pass up to 30,000 cubic feet of water per second, or enough water to fill 1,000 swimming pools in one minute. The weir will maintain water levels downstream of S-65E, protecting it from extreme water level differences and potential failure during major storm events.
In January, the SFWMD Governing Board gave District staff an emergency authorization to proceed with protective measures at S-65E, S-71, S-72 and S-84 at a cost of up to $25 million.
The South Florida Water Management District is a regional, governmental agency that oversees the water resources in the southern half of the state -- 16 counties from Orlando to the Keys. It is the oldest and largest of the state's five water management districts.
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