JACKSONVILLE – “This time of year, it’s all about the storms,” Col. Andrew Kelly, commander of the U.S. Army Corps Jacksonville District, explained Aug. 20, 2021 at a media briefing.
Hurricanes Fred and Grace had little impact on Lake Okeechobee, Kelly explained. “There really wasn’t anything outside of normal due to Fred,” the colonel said. The lake rose about 3 inches in the past week.
“There is another potential storm coming off the coast of Africa that is on the same track that Fred and Grace were so we are mindful of what is happening,” Kelly added. This time of year, with the lake the way it is, lake releases are made on a week-by-week decision.
“We’re OK right now,” Kelly continued. “I am potentially optimistic that things will be OK for the next couple weeks.” That could change if a hurricane heads toward Florida.
“We’re entering the peak of hurricane season,” Kelly said. “About 80 percent of storms that hit Florida happen between now and the end of November. I do not see a change in the immediate future, but it’s all storm dependent.”
The colonel said the lake algae situation is about average. “Some days are better than others, depending on wind and rain,” he explained. He said the corps monitors the algae samplings taken near the structures where they may release water. All of the recent samples near water control structures have shown no toxins or barely detectable levels of O.1 or 0.2 micrograms per liter of microcystin, he explained. The World Health Organization and the Environmental Protection Agency consider microcystin levels below 1 microgram per liter to be safe for drinking water and levels below 8 micrograms per liter to be safe for human recreational contact.
“Florida Department of Environmental Protection is doing fantastic on the monitoring,” he added. Thirty-two sites on the lake are regularly sampled. In addition, FDEP also samples sites of reported algal blooms.
“We are mindful of the need for releases depending on the storms we are watching,” Kelly said.
On Aug. 20, the lake level was 14.41 feet above sea level. The average for this time of year, based on the period of record, is just over 14 feet.
No water from the lake is being released east or west to the coastal estuaries.
Kelly said the target flow to the east is 1,000 cfs, measured at the Franklin Lock (S-79 water control structure) which is more than 40 miles from the connection to Lake Okeechobee at Moore Haven. Since the wet season started, little lake water has been sent to the Caloosahatchee because there was more than 1,000 cfs of local basin runoff. For the past week, flow at the Franklin Lock was bout 2,800 cfs, all from local basin runoff.
There has been no flow to the St. Lucie River from Lake Okeechobee since April. When the lake level was below 14 feet, water from the St. Lucie Canal (C-44 canal) backflowed into the lake. Since the lake is now too high for water from the canal to backflow into the lake, the canal is being managed through the St. Lucie Lock (S-80). Average flow for the past week was about 300 cfs – all from local basin runoff.
“The lake is 14.41 feet. Any water that goes into the C-44 canal from the basin has to go. It can no longer come back into the lake because the lake is too high. It’s not a choice anymore. It’s gravity driven,” he said. To manage that canal, the water goes out the S-80.
“The C-44 canal typically gets up around 14.5 feet above sea level. If there’s more water that comes into the basin, that raises that canal past 14.5 feet, it has to go out the S-80,” he said. Caulkins Water Farm, which draws water from the C-44 canal, is operating, Kelly continued. That helps reduce the canal flow to the St. Lucie.
About 1,600 cubic feet per second (cfs) is flowing under the Tamiami Trail to Everglades National Park. That water is coming from rainfall south of the lake. For about the last month, there hasn’t been any lake water moving south from the lake due to heavy rainfall south of the lake. “The water in the basin is not conducive for additional lake water,” he explained. The WCAs (water conservation areas) are doing pretty well. They’re on schedule. It’s just not lake water.
“Every time it rains, water lands everywhere and it flows into all of the canal system and every place it can,” said Kelly. “There’s water that lands in the WCAs. There’s water that lands in the miles of canals.
“There’s a lot of water in the system and it is the wet season in Florida,” he said.
Kelly said all release decisions include input from the scientists who study the estuaries, the rivers and Everglades National Park. “Every week in preparation for release decisions, the scientists get together, discuss conditions in estuaries, the park, the southern part of the system,” Kelly explained. “We work with our partners with South Florida Water Management District.” He said the advice from the scientists “frames how we are able to understand what is happening and the potential for releases when we have choices.”