Lake Okeechobee dropped below 13 feet (above sea level) this week, putting the big lake in better condition for the start of the rainy season.
“May is a transitional month that can vary from very wet to very dry as we move into the rainy season,” said Col. Andrew Kelly, U.S. Army Corps of Engineers Jacksonville District Commander on May 28. “After the very wet start of the dry season in October and November last year, we were fortunate that the weather in May turned out to be significantly drier than normal and allowed the lake to recede so much. This is great news for the estuaries because it reduces the risk of prolonged, high-volume releases from the lake this rainy season.”
The lake level Friday was at 12.91 feet, which is 0.34 feet lower than last week and 1.16 feet lower than 30 days ago. While the lake is still 1.55 feet higher than last year on this date, it is 0.23 feet lower than the period of record average lake level for this date.
"The recession rate has held true to form the way we want it to," he said.
Kelly said 3,900 cfs is flowing south from Lake O, representing 66% of all flow from the lake.
He said the South Florida Water Management District is doing an phenomenal job dealing with "on the spot" algae situations.
The U.S. Army Corps of Engineers (USACE) Jacksonville District will reduce Lake Okeechobee releases at the W.P. Franklin Lock and Dam (S-79) from the current weekly average of 1,500 cubic feet per second (cfs) to 1,000 cfs beginning May 29.
The 1,000 cfs freshwater flow, measured at the Franklin Lock, is considered to be the most ecologically beneficial for the estuaries. The Caloosahatchee River needs some freshwater flow from the lake in the dry season. Flows below 450 cfs are deemed harmful because the salinity levels rise too high. Flows above 2,800 cfs are considered harmful because the salinity levels drop too low. Lee County officials have requested a freshwater flow in the dry season of at least 1,000 cfs.
"The Caloosahatchee needs freshwater," said Kelly.
The Franklin Lock is 43.4 miles from the Moore Haven Lock, where water from the lake enters the river. If there is enough basin runoff for flow to meet the target flow at the Franklin Lock, no lake water will be released at Moore Haven. Flow at the Franklin Lock may exceed the 1,000 cfs target if there is heavy rainfall in the basin that drains directly into the river.
USACE will continue to release water at beneficial levels to the Caloosahatchee in a pulse pattern after feedback from stakeholders on the West Coast reported some improvement in algae conditions along the estuary after two weeks of similar pulse releases. The use of pulse releases instead of a steady flow is intended to allow tidal flushing into the upper estuary and help combat the formation of algae in the estuary.
No lake water will be released to the St. Lucie River at the St. Lucie Lock. There is some flow from the lake at Port Mayaca into the St. Lucie Canal to meet water supply needs in that basin. For the past seven days (ending May 28), average flow at Port Mayaca into the C-44 canal has been 205 cfs. Permitted water users draw water from the C-44 canal.
The St. Lucie Lock and Dam (S-80) remains closed and USACE continues to manage the C-44 canal levels at the Port Mayaca Lock and Dam (S-308). As long as the lake remains below 14 feet, excess canal water can flow into the lake rather than through the S-80, although locally heavy rainfall may still require S-80 to open.
Kelly noted the Florida Department of Environmental Protection’s (FDEP) recent testing shows significant improvement in toxin concentration within the lake over the past few weeks. There are still some areas above the Environmental Protection Agency’s 8 parts per billion level recommendation for recreation, but none of the very high level sample results from several weeks ago.
NOAA images indicate the algae coverage on the lake has decreased, he added.
USACE will continue to post warning signs at its structures and facilities as directed by county health departments and will continue to closely coordinate with our partners at FDEP as they monitor algal blooms in Florida waters.
"We're about ready to enter the hurricane season," said Kelly.
"The more dry we get, the better position we are," he said.
Kelly said the rain forecast for the area around Lake Okeechobee calls for about half an inch of rainfall next week.