Lake O releases slow, but cyanobacteria detected
Last week, the U.S Army Corps of Engineers announced it would slow freshwater releases from Lake Okeechobee to the Caloosahatchee and St. Lucie rivers.
Starting on June 22, the Corps reduced flows, and started measuring output to the Caloosahatchee at the W.P. Franklin Lock to incorporate watershed runoffs into the count.
The flows slowed to a target range of 3,000 cubic feet per second from 4,000 cubic feet per second from Lake Okeechobee; however, the river was getting around 8,000 cubic feet per second from both the lake and its own watershed.
“It’s still over the harm threshold, but I’ll take it,” Rae Ann Wessel, director of natural policy for the Sanibel-Captiva Conservation Foundation, said.
On June 22, Lake Okeechobee was measuring at 14 feet. That is within the range the Corps tries to maintain, said John Campbell, acting chief of the communications office for the Corps’ Jacksonville District.
“Even at 14 feet, it’s above where it was pre-Irma,” Campbell said. “We try to have the lake 12.5 (feet) to 15.5 feet. Caveating that, we’d rather be closer to 12.5 feet at wet season.”
On June 20, Gov. Rick Scott directed Florida Department of Environmental Protection Secretary Noah Valenstein to issue an emergency order urging the Corps and South Florida Water Management District to take emergency actions to help redirect the flow of water out of Lake Okeechobee to the south. In addition, the SFWMD issued a press release outlining some steps being taken to release and store water elsewhere south of the lake.
According to officials, the order allows additional flexibility for the SFWMD and Corps to work together to explore emergency actions to reduce discharges to the coastal estuaries. Prior to the releases, the SFWMD had been maximizing opportunities to lower water levels in all three water conservation areas south of the lake. The emergency order provided additional opportunities to move clean water out of the water conservations areas to the south.
Steps included installing temporary pumps in southern water conservation areas to pump water into canals, creating more storage capacity; storing water on public land; using canals to move water; and “working with private land owners” to store water on private property.
But there are not too many hard numbers in the press release, detailing exactly how much water will go south. The release mentions 400 cubic feet per second of water being moved out of water conservation area 3A; 200 cubic feet per second being moved out of 3A with a temporary pump; moving 400 cubic feet per second from the L-8 canal to prevent back flow; and 200 cubic feet per second out of 2A into the North New River in Broward County. Water Conservation Areas 2A and 3A are within the Everglades Wildlife Management Area, which is roughly east of Big Cypress National Preserve, north of Everglades National Park, south of the Palm Beach/Broward County Line, and west of Miami.
“We won’t see the effects until next week,” Wessel said at the time. “I don’t know how much they can send to different areas. How much will be redirected, I’ll be interested.”
Wessel said the amount of releases started at the end of May was equal to the water Lake Okeechobee was taking in from two canals that back-flowed into the lake: L-8 and the Clewiston Industrial Canal.
“If you hadn’t had the backflow, you wouldn’t have had to release,” she said.
Campbell said the L-8 Canal has attracted a lot of attention.
“The flows were uncontrolled. Someone wasn’t opening a gate, when the canals get to a certain level it can go any direction,” he said.
Some of the canal’s water went downstream, but some did come back through a “flap gate” into the lake.
The Clewiston Canal is operated by the SFWMD.
“The purpose of the structures throughout Florida, there’s a host of pumps and canals that provide flood risk reduction for property owners,” Campbell said.
Part of the issue for the Caloosatachee was its own watershed.
The Corps was releasing water from the lake at about 4,000 cubic feet per second, but the river was getting an additional 4,000 cubic feet per second influx from its own watershed run-off.
That additional runoff source needs to be identified, said Sanibel Mayor Kevin Ruane. He has been rallying other mayors and municipalities together in a call to action to stop the releases for now.
On June 19, Lee County approved funding to place three additional monitors out in the watershed to find out where the extra water comes from.
“We’re thrilled with what the county commissioners have done,” he said. “I think our call to action just brought this front and center again.”
He also noted that three other monitoring sites may be coming in the future, from a different funding source, but that information could not be confirmed by the deadline for this story.
Ruane is supportive of the SFWMD’s efforts to loosen up capacity south of the lake. But, he said, it is important for the public to continue to stay involved and cognizant of the issue.
“We have a voice, a collective voice,” he said.
Wessel also said she’s “absolutely pleased” with the efforts to send water in “all directions” instead of flooding the two estuaries on the coasts.
While the flow from the Caloosahatchee might have slowed, the damage from the releases can already be visibly seen.
“Our marine lab had ID’d clumps of algae from Beautiful Island to Iona Cove,” Wessel said. “There was freshwater cyanobacteria through the water column.”
Beautiful Island is an island in the river near the intersection of Interstate 75 and Highway 80. Iona Cove is near the mouth of the river.
That was a few weeks ago; and just last week, Wessel said Lee County’s environmental lab also detected cyanobacteria, which was sent to the FDEP for further analysis.
Then, John Cassani of the Calusa Waterkeepers sent out photos he took June 22 of the Caloosahatchee from Alva to about the Ortona Lock, east of LaBelle. Streaks of bright green algae blooms spread through the river’s naturally dark water.
Green algae does not form toxins; cyanobacteria, or blue-green algae, has the ability to release toxins but does not always do so.
“Blue green algae have the ability to turn toxins on or off,” Wessel said.
And someone cannot tell from looking at algae whether it is toxic or not – it is odorless, too. It has to be sampled, and it can take days before the results come back.
“If you’re fishing in the river or on the beach, you can’t tell,” Wessel said.
Lake Okeechobee also has what Wessel said was a significant algal bloom within its waters, covering about a third of the lake and visible from satellite images.
Also in the last few weeks, Wessel and the SCCF team have seen “massive” clam die-offs and oyster kills.
“They were floating in the water, dead,” she said.
Marine animals that did not have the ability to swim away suffered from a lack of salinity in an area of the river and estuary where saline and fresh water typically come together and mix. Instead, the releases have pushed the salt water further back.
“Marine organisms are very resilient and accommodating, but twice a day seesawing between these levels – it becomes a duration issue, too,” Wessel said.
The freshwater coming from the Caloosahatchee has also been feeding the red tide bloom in the Gulf of Mexico, which has been sticking around since September.
The influx of freshwater does not cause red tide. Red tide forms in the Gulf and moves onshore, Wessel said. What the releases do is flush nutrients like nitrogen and phosphorus from stormwater run-off to the red tide, helping it sustain itself.
“It’s independent of Lake O releases,” she said. “The nutrient funnel into the coastal waters, that keeps the bloom alive.”
Wessel said she thinks it would help if agricultural properties had to have stormwater runoff ponds, similar to requirements of urban developments. The same nutrients that feed red tide are collected in the ponds and ingested by the plants living there as a food source.
“Continuous red tide, the cyanobacteria blooms, tell us we’ve degraded the system,” she said.
And the releases could change if Florida should experience another wide-spread rain event as it did in May.
“It depends on the rainfall, and how long. We don’t have complete clarity on that,” Campbell said.
Earlier this year, Wessel was asking the Corps to release more water, as the estuary was not getting enough freshwater into the system and salinity was creeping too far up the river. Her requests were denied – until the rains in May caused the Corps to open the gates from Lake Okeechobee.
But Campbell said in January, weather models were predicting a dry streak. At the beginning of the year, the lake was still elevated, but then the Corps started seeing the lake recede naturally from evaporation and a lack of rain. The Corps has to balance retaining enough water to meet the water supply needs during dry season while keeping it at a level that it can take a heavy rain event, he said.
“The forecasts were trending dry. Based on the information available at the time, (the lake) receding at an above-average pace, plus the longer forecasts, led us to conclude we’d be better off holding it,” Campbell said. “Then in May, the forecast changed to a long-term wet season.”
While the May rains – and Subtropical Storm Alberto – kicked off the hurricane season earlier than normal, the wet season has not been “as wet” since. But still, with the lake at 14 feet, large amounts of rain could raise the lake level again.
“This early, we need to have space to mitigate impacts of tropical systems that have the potential to be a big rainmaker,” Campbell said. “We’ll have to see what the weather does.”