Lake water provides beneficial flow to Caloosahatchee River

Posted 11/18/22

People on Florida’s east coast often ask, why is more water released from Lake Okeechobee to the Caloosahatchee River...

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Lake water provides beneficial flow to Caloosahatchee River

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People on Florida’s east coast often ask, why is more water released from Lake Okeechobee to the Caloosahatchee River than to the St. Lucie River.

The simple answer is the Caloosahatchee River needs freshwater flow from the lake in order to keep the estuary in a healthy salinity range. The St. Lucie River does not need freshwater flow from the lake.

The U.S. Army Corps of Engineers (USACE) Jacksonville District will resume releases from Lake Okeechobee to the Caloosahatchee Estuary from the Julian Keen Jr. Lock and Dam (S-79) at a 14 average pulse release of 1,200 cubic feet per second (cfs) beginning Saturday, Nov. 19. No lake releases are planned for the St. Lucie Estuary.

The 1,200 cfs target is right in the middle of the REstoration COordination & VERification (RECOVER) optimal flow envelope for the Caloosahatchee. Water from the lake will only be released in amounts needed to supplement local basin runoff to meet the target of 1,200 cfs, and the target is consistent with the recommendation from the South Florida Water Management District for this week.

The releases are measured at the Franklin Lock which is more than 40 miles from the Julian Keen Jr. Lock, where lake water enters the Caloosahatchee River. If there is sufficient local basin runoff to meet the target flow, no lake water will be released.

"Lake Okeechobee has risen 3 feet in the past seven weeks due to Hurricanes Ian and Nicole,” said Col. James Booth, Jacksonville District commander on Nov. 18. “We had paused our releases for Hurricane Nicole and have not made releases since the storm. Based on conditions in the lake, we must begin releases to help manage lake levels. We have worked together with our partners and stakeholders to understand how lake releases could affect conditions in the Caloosahatchee River Estuary at this time. We are making our decision looking ahead toward next wet season and are developing a seasonal strategy where we aim to manage lake levels by making beneficial releases to the extent possible. To curtail the high-volume releases that our plan calls for right now, we are going to utilize our make-up release tool which allows us to make releases at lower levels and bank the volume not released."

Make-up releases are a water management tool within the Lake Okeechobee Regulation Schedule 2008 (LORS08) which allow water managers to bank releases not made in order to release them later when the schedule calls for lower releases. LORS08 Part D guidance currently recommends up to 4,000 cfs at S-77 and up to 1,800 cfs at S-80. The volumetric difference between actual releases and the guidance will be put into a water bank. As conditions in the estuaries recover and the schedule goes into dry season mode, releases will be continued using the available volume of banked water, the colonel explained. “Our intent is to release this volume at beneficial levels in the dry season. We are committed to transparency throughout the implementation of make-up releases.”

With the lake over 16 feet, USACE has been inspecting the south side of the Herbert Hoover Dike from Moore Haven to Belle Glade every two weeks, Once the lake reaches 16.5 feet, the frequency of inspections on the south side of the lake increase to weekly and the remainder of the dike begins receiving inspections every two weeks.

The dike was inspected thoroughly before and after Hurricanes Ian and Nicole, and no problems were identified.

Lake Okeechobee is 16.30 feet today. That is 0.16 feet higher than last week, 0.94 feet higher than 30 days ago, and 0.3 feet higher than it was on this day last year.

Lake Okeechobee, Caloosahatchee River, releases

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