With Hurricane Irma bearing down on the Leeward Islands in the Caribbean, water managers in South Florida are bracing for heavy rainfall they say could exacerbate high water issues from record-setting rains the region experienced earlier this summer.
"We're probably looking at eight to 10 inches, depending on the path," said John Mitnik, chief engineer for the South Florida Water Management District, at a Tuesday morning press conference. "Getting 10 inches of rain, if it all comes in one big gush, you'll be fighting that water for days."
Mitnik said the district is lowering water in its canals so local drainage districts — counties, condo associations, neighborhood associations and the like — can release water out to tide.
Inspections and monitoring are underway, and the district is prepared to begin 24/7 pumping, he said.
"It just depends on where the rain falls and how hard the rain falls," Mitnik said.
Flooding in swaths of the Everglades, including portions of western Broward and Miami-Dade, counties has been a problem for much of the summer following a sodden June. The rainfall forced the U.S. Army Corps of Engineers to release excess water into the ecosystem, a decision that wildlife managers and environmental activists say was necessary but threatened the habitat of the endangered Cape Sable seaside sparrow.
Corps spokesman John Campbell said the releases helped relieve pressure on overflowing water management areas, but that water levels remain concerningly high as Irma looms.
"A lot of capacity was taken up with the rain in June," he said, adding that the Corps has activated its emergency operations center.
The news is better farther north. The water level in Lake Okeechobee on Tuesday morning was 13.67 feet, which is under the 15.5 feet the Corps uses as a benchmark to begin discharging water. Campbell said that's in contrast to last summer when high lake levels and concerns over flooding prompted the Corps to begin discharging water east and west through the St. Lucie and Caloosahatchee estuaries, fueling blooms of foul-smelling blue-green algae along Florida's coasts.
As a precautionary measure, the Corps announced Tuesday evening it would begin discharging water.
"We want to be ready for the heavy precipitation from Irma," Col. Jason Kirk, the Corps' Jacksonville District commander, said in a statement. "We anticipate direct rain over the lake could add a foot to the water level."
Kirk said the Corps anticipates the releases will last a short time.
"We will only be able to release water for about three days at these rates," he said. "As the storm gets closer, we'll have to close all the gates around the lake to reduce the risk from potential storm surge that may develop from high winds on the lake."
Along with South Florida, Puerto Rico and the U.S. Virgin Islands fall under the purview of the Jacksonville District of the Army Corps. Campbell said the Corps has begun sending staff to those regions -- both under hurricane warnings -- to help prepare for the storm. Irma is likely to make landfall in Puerto Rico and the islands on Wednesday, the National Hurricane Center said in an advisory issued 2 p.m. Tuesday.
This post was updated following the Corps' announcement it would begin discharging water from Lake Okeechobee.