MIAMI --When Hurricane Irma charged across the state last month, coastal communities hammered by powerful storm surges attracted the most attention. But inland Lake Okeechobee, the state's 730-square mile liquid heart, also took a hit.
Lake levels already high from the wettest rainy season in 86 years shot up 3 1/2 feet, raising concerns about the shallow lake's aging dike. Marshy edges that provide nesting habitat for endangered snail kites and fishing holes for anglers disappeared under brown water. With tropical storm force winds swirling across the lake for more than 24 hours, dirty water mixed with polluted sediment on the lake bottom.
About 5,300 acres of vegetation, made up mostly of cattails, was uprooted and tossed into the mix, eliminating a protective boundary that helps keep turbid water from the lake's interior away from its cleaner fringes.
This past week, for the first time in weeks, water levels in the lake began receding. But the environmental consequences of Irma remain a concern.
"Turbidity in the lake itself, that's a situation that's going to persist for a while," said environmental scientist Susan Gray, chief of Applied Sciences at the South Florida Water Management District. "After 2004 and 05 (when five hurricanes hit Florida) it took a year and a half to clear up."
And all that dark water could cause even more submerged plants to die, said Audubon Florida's Lake Okeechobee science coordinator, Paul Gray.
"Pretty ugly out there right now," he said in an email, predicting the plants would not survive the high water for so long.
Irma spread tropical storm-force winds across Lake Okeechobee for at least 30 hours Sept 10 and 11, mixing dirty lake water with sediment at the bottom of the lake polluted from decades of runoff from neighborhoods, farms and ranches to the north. Scientists are now worried that the turbid water will remain and could damage plants and animals along the lake's fringes.
To the south, the situation is more dire in water conservation areas where tree islands provide shelter for deer, raccoons, opossums and nesting wading birds across more than 1,300 square miles, said the district's Everglades chief scientist, Fred Sklar. While the threat of flooding neighborhoods is far lower, the hits to wildlife could be unprecedented, he said.
By Sklar's estimate, by the time the district can drain water, the islands will probably have been underwater for 288 days, about three weeks longer than the previous record.