FORT MYERS, Fla. – Caloosahatchee River flows are looking good at a time when algae is absent from the entire system, and other health indicators seem promising as the region transitions into the brunt of the dry season.
The U.S. Army Corps of Engineers is releasing just over 2,000 cubic feet per second at the W.P. Franklin Lock in Alva, and about half of that water is local basin runoff, according to Army Corps records.
“I think 2,000 (cubic feet per seconds) is fine,” said Calusa Waterkeeper John Cassani. ”(The Corps) is just trying to keep that salinity envelop where it needs to be before it gets really dry. That’s important.”
Cassani said the river and its estuary begin to suffer once flows are in the 500 to 600 cubic feet per second or less for an extended period of time.
“It’s about keeping the salinity in the healthy range,” Cassani said.
The basin stretches from the western shores of Lake Okeechobee to San Carlos Bay and the Gulf of Mexico.
“That 2,000 (cubic feet per second) target is within the ecological envelope set by (recovery goals) for flows to the Caloosahatchee,” said Jim Yokum, spokesman for the Army Corps. “And the salinity ranges for oysters is still in the good range as of (Nov. 23) for both Shell Point and Sanibel.”
Salinity levels for the estuary are measured in the downtown Fort Myers area.
Releasing more Lake Okeechobee water down the Caloosahatchee River could cause concerns over aquatic vegetation that requires a certain amount of light to thrive.
“The high levels of tannins stain the river and block out the light, and the other part is nutrient concentrations continue to rise in the estuary and the river,” Cassani said of any additional Lake Okeechobee water. “The algae grows on the shoots of the grass and that creates a shading effect on the tape grass and the other species.”
Lake Okeechobee surface levels are still relatively high at 16 feet above sea level.
Under current regulations (the Lake Okeechobee Regulations Schedule, or LORS), lake levels are typically kept between 12.5 and 15.5 feet above sea level to provide flood protection and water for agriculture and urbanized areas as well as natural systems like the Caloosahatchee and the famed River of Grass.
Blue-green algae has been reported by the Florida Department of Environmental Protection at the S-77 water control structure that connects the lake to the Caloosahatchee River.
Bloom conditions were also documented recently by DEP on Lake Trafford in Collier County.
But the rest of the Caloosahatchee system tested negative for blue-green, according to DEP records.
Fall is often the time of year when red tides initiate, but blooms occur during all months, according to the Florida Fish and Wildlife Conservation Commission.
A bloom that stretched from the fall of 2017 until the spring of 2019 was particularly bad for Southwest Florida, especially during the toxic summer of 2018.
But conditions were mostly clear in the river this past summer, and recent FWC reports for the Caloosahatchee show only background levels of the potentially toxic organisms.
Anecdotally, the river is in good health as the fishing has been “pretty good,” according to Mike Westra.
His family owns Lehr’s Economy Tackle in North Fort Myers and has lived along and fished the river for generations.
”(The fishing) was good throughout the summer,” Westra said. “During the winter months when we have a lot of freshwater coming down the river, people kill it.”
Westra said he expects river conditions to be steady this upcoming winter.
“I think it’s going to be a fairly exceptional season,” he said.