Lake Okeechobee remains high despite some drier weather in recent weeks.
The month of January brought well below average rainfall, according to the report presented by Chief District Engineer John Mitnik at the Feb. 9 meeting of the South Florida Water Management District (SFWMD) Governing Board. “Everybody is still reeling from the excessive rains back in September,” he added.
He said the projected data for Lake Okeechobee indicates “there’s roughly a 50% chance come June 1 that lake stages will be somewhere between 13 and 14 feet.”
Lake Okeechobee was 15.59 feet on Feb. 9. He said the lake is not coming down as quickly as many people had hoped.
“The lake’s got some challenges ahead of it as far as lake stage and operational management,” he said.
The district is moving water south from Lake Okeechobee through Stormwater Treatment Areas (STAs) into the Water Conservation areas (WCAs), he added.
Since the start of the current water year on May 1, 2022, more than 2 billion acre feet of water has flowed into Lake Okeechobee. That’s roughly equivalent to about 4.5 feet on Lake Okeechobee. (Water Year 2023 is from May 1, 2022 to April 30, 2023.) Much of that water came from the north, as flood waters from Hurricane Ian were pumped south into the Kissimmee River to relieve flooding in the urban areas of Orlando/Kissimmee.
The report showed during the past water year, 52,000 acre feet flowed to the St. Lucie, with about 11,000 acre feet of that water coming from Lake Okeechobee. However, during the same water year, 28,900 acre feet of water flowed from the C-44 basin into Lake Okeechobee. When the lake is below 14 feet above sea level, water from the C-44 Canal (aka St. Lucie canal) backflows into Lake Okeechobee if the water control structures are open.
Inflows to the Water Conservation Areas (WCAs) from all sources have been about 1.3 million acre feet. About 1.3 million acre feet of water has flowed into Everglades National Park. Just under 1 million acre feet of water has been treated by the Everglades Agricultural Area STAs this water year; about 25,000 acre feet of that water came from Lake Okeechobee.
Mitnik said that during the months of November and December, no water from Lake Okeechobee moved into the STAs because water managers had to give the STAs a break following the high water levels created by heavy rainfall during the wet season.
“We need to get the lake down,” said SFWMD Executive Director Drew Bartlett. “The lake communities are very stressed about the condition of the lake right now. We need to get it down to prepare for the wet season, but we don’t need to set our hair on fire. Mother Nature works it out most of the time,”
“The lake ecology is stressed, based on the depth,” said SFWMD Governing Board Member Jay Steinle. “We’re concerned about SAV (submerged aquatic vegetation) loss. We’re concerned that the lake has taken a massive load of nutrients after the storms that we had this fall. We can’t send more water south because the STAs have capacity limits. Our options are the three levers that we have to pull – St. Lucie, Caloosahatchee and the (Lake Worth) Lagoon. If that’s the case, we’re also in a period that if we wait to flush, or if the corps waits to flush and we’ve got a brew of algae beginning to happen in the summer. I think what the corps is doing now is the only action that we can take, which is to release when conditions are less favorable to algae blooms and to do it to the extent that it balances what we don’t know with what we’re going to get from the climate.”
“Northern storage – you need storage north of the lake. That’s something that needs to be said out loud and it needs to be said often,’ said Governing Board Member Scott Wagner. He said discharges to the coastal estuaries might be psychologically stressful to coastal residents but the releases aren’t ecologically stressful to the estuaries. “Better now, to me, in February than in June and July.”
In the Ecological Conditions Report, Water Resources Division Director Lawrence Glenn said the Kissimmee River flood plain is in good condition.
“As we move further in the dry season, ET is going to take a lot of water out of the lake,” he said.
“We are still a good foot above the ecological envelope,” he said. The SAV coverage on the lake is one of the lowest in the past decade. There was only about 5,000 acres of SAV before Hurricane Ian hit and Ian took out about half of that.
“If we hit 13 feet, the SAV we have now, we can maintain that,” he explained. For regrowth of SAV, lake levels of 12.5 feet or 12 feet are needed.
“So this upcoming year, if we don’t get below 12.5 (feet), we don’t see a chance of recovering the SAV,” he said. “But if we get to 13 feet, we can retain the SAV we have now.”
He said there are no algae blooms or toxins in the lake water right now, but with lake level so high they are concerned about potential blooms this summer.
He said there is not enough SAV or other vegetation to compete with the algae for the nitrogen and other nutrients in the water.
“We can anticipate a pretty robust blue-green algae season on the lake,” he said.
Glenn said because the lake is deep, the water in the marsh is too deep for use by wading birds.
Despite the lake releases to the St. Lucie, salinity is in the good range for adult oysters in the St. Lucie Estuary and the spawning season is over, Glenn said. He said if they need to release lake water, now is the time to do it.
The Calooshatchee River is also enjoying a good salinity range, he said.
“What we’re doing right now from an ecology standpoint is really good and it is the right time to do it.”
On Feb. 14, Lake Okeechobee was at 15.87 feet above sea level. The lake's ecological envelope ranges from 12 to 12.5 feet at the start of the wet season (around June 1) to 15.5 feet at the start of the dry season.
When the lake level is above 15.5 feet, the water stacks up against the Herbert Hoover Dike, an earthen berm which encircles the lake for flood control.