CLEWISTON — On wind-whipped days when rain pounds this part of South Florida, people are quickly reminded that Lake Okeechobee, with its vulnerable dike and polluted waters, has become a giant environmental problem far beyond its banks.
Beginning in May, huge downpours ushered in the most significant threat in almost a decade to the bulging lake and its 80-year-old earthen dike, a turn of events with far-reaching consequences. The summer rains set off a chain reaction that devastated three major estuaries far to the east and west, distressing residents, alarming state and federal officials, and prompting calls for remedial action.
With lake waters at their limit, there were only two choices, neither of them good. One was to risk breaching the 143-mile dike, a potential catastrophe to the agricultural tracts south of the lake and the small communities that depend on them. The other was to release billions of gallons of polluted water into delicate estuaries to the east and west.
Following its post-Hurricane Katrina guidelines, the Army Corps of Engineers chose the estuaries, rather than test the dike's vulnerabilities.
As a result, the St. Lucie River estuary in the east and the Caloosahatchee River estuary in the west, which depend on a naturally calibrated balance of saltwater and freshwater, were overwhelmed. The rush of freshwater from the lake and the estuaries' own river basins, along with the pollutants carried in from farms, ranches, septic tanks and golf courses, has crippled the estuaries and, on the east coast of the state, the Indian River Lagoon.
As breeding grounds for marine life, estuaries are crucial to the ecosystem. As algae caused by pollutants quickly spread and freshwater overpowered saltwater, oysters died in droves. Manatees, shellfish and the sea grasses and reefs that help sustain the estuaries all were badly hit.
"These coastal estuaries cannot take this," said Mark D. Perry, executive director of the Florida Oceanographic Society, based in Stuart. "Enough is enough. This cannot continue to happen. These estuaries are so important to us, our environment and our economies."
The damage to the estuaries has been so profound and the clamor from local communities so intense that political leaders have pledged action. Gov. Rick Scott, a Republican, visited the affected areas last month and proposed spending a total of $130 million for two separate projects.
One is intended to ease some of the pressure on Lake Okeechobee by allowing more water to go south into the Everglades, where it should flow naturally. The water will flow under a series of bridges that will be completed over the Tamiami Trail. By law, the water flowing into the Everglades is filtered and treated, unlike the water that heads to the estuaries.
South Florida was expressly engineered to prevent too much water from moving south, which is why most of the flow from the lake is pushed east and west. Canals to the south were dug to make way for agricultural fields, mostly containing sugar cane, and for urbanization. The little water that is released flows around those areas.
Environmentalists have fought for decades to correct the flow into the Everglades, a gargantuan and costly undertaking.
A second project would clean more of the polluted water in the St. Lucie River Basin that flows into the river. There are plans for a similar stormwater treatment area on the west coast to help curb the damage.
A top priority is repairing the frail Herbert Hoover Dike surrounding Lake Okeechobee, which is more than half the size of Rhode Island and is renowned for its bass fishing. A 2006 report on the lake found that the dike, long ranked among the most vulnerable in the country, posed a "grave and imminent danger."
But the repairs will take time and large amounts of money.
Last year, the Army Corps of Engineers finished shoring up one section of the dike. It has now shifted gears and is working on replacing or repairing some of the lake's 32 huge culverts and conducting a further analysis of the dike.
"It doesn't take long at all to realize what a complex web water management is in South Florida," said John Campbell, a corps spokesman. "There are no easy fixes anywhere."
Scott has accused the federal government of dragging its feet on making dike repairs and paying its share of the cost. But environmentalists say Scott and the Legislature have slashed the budget of the South Florida Water Management District, which oversees the state's water flow, and have put in place some inexperienced managers.
Meanwhile, the peak of hurricane season has arrived.
"The lake is slowly beginning to recede a bit," said Ernie Barnett, the interim executive director of the South Florida Water Management District. "But the concern is still there. All it will take is one tropical storm to put us in a massive crisis mode."
The rush of freshwater, both from the lake and from its own river basin, has had an immediate impact on the St. Lucie River estuary to the east. Life in and around it has come to a standstill this summer — one recent afternoon, boats could be tallied on one hand. Fishing piers sat forlorn. And any fish capable of swimming away have already done so.