Posted on June 23, 2021
New operating plans for managing Lake Okeechobee would raise the lake at least 1.5 feet once the U.S. Army Corps of Engineers completes $1.8 billion in repairs to the aging Herbert Hoover Dike.
The plans, previewed Thursday, all allow the 730-square-mile lake to jump over 17 feet or higher, drawing concerns about worsening the lake’s health.
“Lake Okeechobee in these runs is the biggest loser,” said Paul Gray, Everglades Science Director for Audubon Florida. “We know that deepwater harm to the lake is pretty bad. When you get to 17 feet by accident, it really causes long-term harm to the lake. And heaven forbid we get to 18 feet.”
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While weather and other conditions may push water higher or lower, the Army Corps sets a range of operational bands — which dictate lake releases that can sometimes fuel toxic algae blooms — to ensure water supply, flood protection and safeguard the health of the lake, rivers, nearby marshes and other habitat. Water levels are now capped at 15.5 feet to protect the dike. The levels rise in the dry winter months and drop in the rainy season.
The lake has battled worsening pollution for decades. And in recent years, repeated algae blooms in the St. Lucie and Caloosahatchee estuaries and drying out marshes in the Everglades have increased pressure to come up with a better operating plan when the dike is finished next year.
“The way that I look at it at this point is this really is the foundation,” Jacksonville District Commander Col. Andrew Kelly said. “I come at it from an agency that builds highly complex and big infrastructure and there is nothing more important than the foundation.”
Kelly said on Friday without the risk of a fragile dike, the Corps was able to increase levels and stretch benefits in other areas.
“That doesn’t mean we’re going to keep the lake at 17 feet year round. There’s no way we could do that. So it’s a matter of how much time do you spend at a perfect spot in the lake over time,” he said.
The bands will ultimately help define an operational manual used for years to come.
In selecting a plan, the Corps will need to balance competing interests: sprawling sugar cane fields south of the lake and utilities that depend on the lake for water supply, along with an Everglades restoration plan now expected to cost $23 billion — that needs the lake to operate as its liquid heart. That means providing water during the dry season while not dumping too much water in the rainy season.
Corps engineers have narrowed the choices down to five. In Thursday’s presentation, lead engineer Jessica Mallett said the Corps had run about 150,000 comparisons looking at how the different alternatives improved various issues, including the risk of algae blooms; water supplies that also include coastal counties south of the lake and Seminole Tribe lands; the health of the lake and Caloosahatchee and St. Lucie estuaries; and navigation and recreation.
Some alternatives fared better at providing water supply while others reduced discharges, lowering the risk for toxic blooms.
But allowing the lake to regularly hold deeper water could do prolonged harm, Gray and others said.
“We’re talking about schedules that are going to put [Lake] Okeechobee in severe impairment and we have a lot of experience with this,” he warned.
From the 1950s through the late ’70s, the lake was managed to keep water below 15.5 feet, which created more even fluctuations between wet and dry periods. That allowed surrounding marshes where snail kites nest to dry out, Gray said. The shallower lake also had fewer algae blooms.
University of Florida aquatic ecologist Karl Havens, who died in 2019, linked deeper water to poorer conditions. In simple terms, deeper water drowns vegetation that can absorb the nutrients that feed blooms and can allow mixing during stormy conditions. That can stir up polluted mud that has built up on the bottom over decades of run-off from farms and communities above the lake.
In 1978, Gray said the lake was allowed to rise above 18 feet, which essentially drowned the marshes and ushered in decades of problems.
“By the year 2000, there’s another emergency declared in the lake because the lake was too deep and [snail] kites weren’t nesting and the fishery had crashed and the [submerged plants] were gone,” he said. “The lake’s not the only consideration we have to make, but these very deep schedules that you guys are contemplating are really ominous for the health of the lake.”
Environmentalists also worry that a higher lake will mean bigger dumps of water if storms or hurricanes, both predicted to grow wetter as the planet warms, hit the lake.
“The concern we all have is not only for the lake ecology, but the potential for downstream conditions to get worse because we have to get rid of the water once we’re in those higher zones,” said Florida Oceanographic Society Director Mark Perry.
The Corps’ technical staff plans to hold two additional meetings on June 22 and June 30. The South Florida Water Management District plans to meet June 29 to review the plans.
