Continued heavy rain prompts additional increase in flows from lake

Published July 19, 2013

The U.S. Army Corps of Engineers Jacksonville District has announced increases in flows from Lake Okeechobee as part of the ongoing effort to manage the runoff from several days of heavy rain in south Florida.

The Corps will increase the discharges beginning Saturday, July 20.  The target flow for the Caloosahatchee Estuary is 6,500 cubic feet per second (cfs) as measured at the Moore Haven Lock and Dam (S-77), and 2,800 cfs for the St. Lucie Estuary as measured at the St. Lucie Lock and Dam (S-80) near Stuart.  These discharge rates will remain in effect until further notice.

Today, the lake stage is 15.24 feet.  The change in the release rate is the result of the lake entering the Intermediate Operational Sub-Band as defined under the 2008 Lake Okeechobee Regulation Schedule (LORS), the master plan for water management of the lake.  In the Intermediate Sub-Band, LORS authorizes larger releases to slow or reverse the rise of the lake.

“This wet season’s above-average rainfall and high water levels are a stark contrast from what we experienced last year,” said Lt. Col. Tom Greco, Jacksonville District Deputy Commander for South Florida. “Lake Okeechobee and the water conservations areas can hold a massive amount of water during rain events, but their capacity is by no means limitless.   Currently, the lake and water conservation areas are above schedule, so taking appropriate steps now to manage water levels is essential.”

Midway through the month, precipitation has been 74 percent above normal for July.  This continues the pattern of above-average precipitation since April. 

“The heavy precipitation has constrained our operations on both sides of the lake,” said Jorge Tous, Chief of the Jacksonville District Water Management Section.  “We’ve repeatedly had to suspend releases due to runoff that has accumulated in the Caloosahatchee River and St. Lucie Canal.  We are hopeful these larger releases will allow us to stabilize the rising lake before we have to maximize flows throughout the system.”

Since the Corps began discharges from the lake on May 8, much of the water passing through the final set of locks to the estuaries has come from basin runoff.  Through July 18, 31 percent of the water going through the Franklin Lock since May 8 has been from the lake, while 33 percent of the water going through the St. Lucie Lock has been from the lake.  

The releases from the lake are necessary to keep water levels from getting too high, putting additional pressure on Herbert Hoover Dike, the 143-mile flood-control structure surrounding the lake.  The dike, parts of which date back to the 1930s, suffers from seepage and erosion problems due to construction methods that were used at that time.  The Corps is concerned that high water levels would increase erosion to the point it could lead to a breach of the dike.  In addition to managing lake levels, the Corps conducts regular inspections of the dike.

Public safety remains the Corps’ top priority. The Corps will continue to monitor and make adjustments as necessary.  Additional increases in the discharge rate may be necessary as conditions change. 

For more information on water level and flows data for Lake Okeechobee, visit the Jacksonville District’s water management page: 

http://w3.saj.usace.army.mil/h2o/currentLL.shtml

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Contact
Jenn Miller
904-232-1613
jennifer.s.miller@usace.army.mil

Release no. 13-052