PAHOKEE, Fla. -- Glenn Gannon stood in dusty, steel-toed boots and white hard hat on the grassy dike at Lake Okeechobee, one of the biggest lakes in America and one of the most worrisome. A blazing sun glistened on the dark blue waters and a tiny breeze rippled the saw grass and cattails. “Occasionally you see alligators,” Mr. Gannon said.
Mr. Gannon, who is a civil engineer, was not drawn to the lake by its wildlife and natural beauty. He was part of a group in the U.S. Army Corps of Engineers that was working to prevent a disaster at the 143-mile-long dike, a catastrophic flood that could kill thousands of people. In 1928, before the dike was built, a flood killed perhaps 3,500 people. Now, more than 40,000 people live around the lake. And there is cause for concern.
The Corps of Engineers keeps a vigil on the dirt and gravel dike inland from West Palm Beach and says that parts of it are in serious trouble, “critically near failure.” The engineers don’t foresee water washing over the top of the dike, as in New Orleans during Hurricane Katrina. The danger at Lake Okeechobee is water seeping through the dirt walls in little wormy, cancerous fingers. Something like Swiss cheese develops and down comes the dike with the potential, the Corps says, for severe flooding with significant loss of life and immense property damage. Lloyds, the British insurance organization, says financial losses could run into the billions of dollars.
The danger has been there for a long time. In 2006 consultants working for a Florida state agency said the dike posed “a grave and imminent danger to the people and the environment of South Florida.” So far, the dike has held. And maybe it always will.
It is hard to calculate the odds of something tragic happening at the lake. But managing the 733 square miles of lake -- more than twice the size of New York City and far bigger than most other American lakes -- is complicated. Experts say there is at least some chance that elaborate safety measures could be overwhelmed.
Heavy rain can pour into the lake six times faster than it can be drained and at certain levels, the Corps of Engineers says, the dike is almost certain to fail. Eric Buermann, the chairman of the governing board of the South Florida Water Management District, which commissioned the consultant’s study in 2006, says he sees the likelihood of a killer-flood as remote. But he also notes that controlling the lake “is a balancing act.”
The lake has a frightening history. A little more than 80 years ago, in 1928, hurricane rains poured into the lake and high winds sloshed tons of water over the southern portion of a much smaller containment wall. The flooding was severe and 2,500 to 3,500 people are believed to have died in one of America’s worst disasters. Bodies were buried in mass graves. No one is sure just how many lives were lost.
Soon after the flood, in the early days of the Great Depression, the federal government began building what is officially known as the Herbert Hoover Dike. Work crews dredged mud, gravel and sand from the bottom of the lake and piled it up on shore. That was it. No iron reinforcing bars. No concrete. Just lake-bottom goop. And that, still today, is the essence of the dike.
The Corps strives to keep the water in the lake below 15.5 feet, especially during the summer when rainfall is heaviest and hurricanes compound the danger. Should the lake rise to 18.5 feet, the Corps says, the chance of the dike giving way is near 50 percent. At 21 feet, the Corps says, the game is up, the dike will surely fail.
Twice in recent years the lake’s waters have risen higher than 18 feet -- 18.5 and 18.6. The Corps says the lake has never yet risen beyond 19 feet.
The federal government takes the threat seriously. It has spent more than $250 million to strengthen the dike in just three years -- 2008, 2009 and 2010 -- and, the Corps says, costs could climb to $1.8 billion before the job is finished in perhaps seven to 15 years.
The Corps recognized the dike was vulnerable in the mid-1980s. But it took Hurricane Katrina and the disaster in New Orleans to shake up Washington and the Corps. Work on strengthening the dike finally got started in earnest in 2008. The Corps of Engineers operates and maintains 675 dams, dikes and levees around the country and it ranks the Lake Okeechobee dike as one of a dozen or so facilities in critical need of attention. Florida International University in Miami says the lake is America’s second most vulnerable place to hurricanes after New Orleans and ahead of the Florida Keys.
So far a stretch of a little more than 8 miles of the dike has been reinforced. Some of those working on the dike say that suggests a pretty rapid pace. But more than half of the most dangerous 22-miles of the dike remains as vulnerable as ever, like the rest of the 143-mile barrier.
The main feature of the project is the insertion of a roughly two-foot wide cement-like wall 60 to 80 feet down through the center of the dike. The wall is intended as a simple barrier to block seepage. The Corps is also putting extra dirt and gravel on the landside of the dike.
On the grassy dike just north of Pahokee on the southeastern shore of the lake, Mr. Gannon showed where a section of the wall had been put in. The top of the wall had been covered with dirt and the crest of the dike looked just as it had before the big red and yellow construction rigs and bulldozers arrived. Down the two-lane gravel path that runs along the top of the dike, Mr. Gannon pointed out where the next work would begin. “This is the starting point,” he said, “right here.”
In Belle Glade, one of the farm towns on the edge of the lake, a sculpture on the lawn of the public library freezes in bronze a frightened woman running with a child cradled in one arm, a man and a boy fleeing with her. The woman’s hair is streaming in the wind, her eyes intense. This is Belle Glade’s way of remembering the tragedy of 1928.
In the town of Clewiston, at the history museum, about half a mile from the dike, William Paul (Butch) Wilson, the director, talked about death and damage in the 1928 flood. Older people grew up hearing about the flood and people driving around the lake see crews working on the dike.
“I think we all know the possibilities,” said Mr. Wilson. “It’s kind of like death. You know you’re going to die. But you don’t dwell on it. We know it’s a factor. We just hope it never happens.”