Environmental Intersection by George Lindemann

With rainfall at a record pace in some places, water managers are struggling to lower water levels in Lake Okeechobee and the Everglades.

From Lake Okeechobee to the marshes of the Everglades, South Florida has been saturated by what is shaping up as the wettest of wet seasons.

Water managers are struggling to deal with high-water concerns across a region left brimming by Tropical Storm Isaac and stubbornly steady storms that have followed in its drenching wake. Some spots are on pace for the rainiest year on record, with Miami leading the list at 79.51 inches through September.

On Wednesday, federal engineers ordered the drainage gates cranked open even wider on Lake Okeechobee, where water levels have climbed nearly a half-foot despite two weeks of release intended to slowly lower them. The decision by the U.S. Army Corps of Engineers to double the flow is primarily intended to ease pressure on the aging and leaky flood-control dike that rings the massive lake, but it will have a side-effect of pouring billions of gallons of polluted water into sensitive river estuaries on both coasts.

In the swollen marshes of the Central Everglades north of the Tamiami Trail, there are no similar relief-valve options to help deer and other wildlife, which have already spent the last month mostly confined to levees and small tree islands, shrinking swaths of high ground where starvation from dwindling food supplies, and diseases like hoof rot, are a growing threat.

Even without more rain, it could take another three weeks to a month for the water to drop to normal seasonal levels, said Michael Anderson, regional wildlife biologist for the Florida Fish and Wildlife Conservation Commission.

“Quite frankly, after about 30 days, they start to run out of groceries on the islands and we start to see impacts,’’ Anderson said.

The Corps’ initial effort to lower the massive lake has already dumped more than 11 billion gallons of freshwater laced with high levels of farm chemicals and nutrients into the St. Lucie River on the east coast and the Caloosahatchee River on the west coast. Similar but much larger dumps after hurricanes in 2004 and 2005 destroyed oyster beds and sea grass, and triggered massive foul fish-killing algae blooms.

But with two months still left in hurricane season and plenty of rain remaining in the forecast, the Corps’ lake managers said they had little choice but to accelerate the damaging releases.

“We just haven’t seen the results we wanted since we started,” said Lt. Col. Thomas Greco, the Corps’ deputy commander for South Florida.

Under the Corps’ management plan, the water level in Lake Okeechobee is supposed to stay between 12.5 feet and 15.5 feet above sea level, rising and falling with seasonal rain. It stood at 15.69 feet on Wednesday.

That’s still well short of the 17-foot level where engineers begin to worry about the integrity of its aging dike, which has sprung leaks during past hurricanes and is undergoing repairs that will take years. But a tropical storm like Isaac can quickly drive up lake levels by two or three feet, which would raise the risk of a potentially catastrophic failure.

The lake has to come down and the Everglades are already too full to send water there, Greco said.

State and federal water managers say they are doing the best they can do with an outmoded and overwhelmed flood-control system that operates under sometimes conflicting regulations to protect suburbs, farms and the Everglades from excessive flooding. A string of Everglades restoration projects, starting with a bridge along Tamiami Trail expected to be completed next year, promises to resolve many of the issues and eventually allow more water to flow south into Everglades National Park. But it could take a decade or more for enough of the projects to come on line to make a significant difference.

For now, water managers are diverting as much water as they can out of the biggest troubles spots in the Everglades — the marshy water conservation areas bordering Miami-Dade, Broward and Palm Beach counties — and sending it down canals into southern Everglades National Park and Florida Bay. State wildlife managers also have temporarily restricted public access to flooded portions of the Everglades and the Francis S. Taylor Wildlife Management Area to ease stress on stranded wildlife.

Flooding decimated the Glades’ population of white-tailed deer in 1982 and 1995, knocking the herd from thousands to hundreds, and killed countless smaller animals that rely on high, dry tree islands for food and shelter.

The FWC’s Anderson said he doesn’t expect that level of loss this time around, barring another major storm, which could keep water levels high even longer.

According to the South Florida Water Management District, which runs the flood control system from Orlando to Key West, seasonal rainfall is running about 114 percent above normal with an average of 37.53 inches across 16 counties.

But some areas have been hit harder than others, with the district showing eastern Broward County experiencing the wettest April through September since 1955, with more than 44 inches of rain — more than nine inches above average. Eastern Miami-Dade has been even wetter, with nearly 50 inches of rain — 13.22 inches above average.

At the official rainfall gauges maintained by the National Weather Service, Miami is on pace to record its wettest year ever, with 79.51 inches measured at Miami International Airport through September. The annual record for that site is 89.33 inches in 1959. The Redland, with 72.69 inches, and Homestead, with 67.58 inches, also are on pace for the wettest years on record. Fort Lauderdale’s Dixie water plant, with 69.24 inches, is the second wettest mark through September on record.

-By CURTIS MORGAN