WEST PALM BEACH, Fla. -- The $10.5 billion government effort to restore the Everglades is being threatened by the ecological collapse of Lake Okeechobee, the primary source of water for the sprawling wetland and the nation's second largest freshwater lake.

Experts say the lake's decline, stemming from massive infusions of polluted water from suburbs and farms, is already responsible for a string of devastating fish kills in the St. Lucie and Caloosahatchee rivers, which have long been used as discharge canals for Okeechobee's excess water.

Now Okeechobee's pollution is threatening the health of the broader Everglades ecosystem, which extends across more than 18,000 square miles, from the expansive sugar cane fields pressing against the lake's south shore to the blue-green waters of Florida Bay.

If pollution washing into Okeechobee is not curtailed within the next few years, experts believe the shallow but broad lake -- roughly 11 times the size of the District of Columbia -- will die, as will the Everglades.

"There is no precedent for the quality of water in the lake being as bad as it is right now," said Tom MacVicar, an environmental consultant who has studied the Everglades for nearly three decades, including 16 years with the South Florida Water Management District.

The district, along with the Army Corps of Engineers and various stakeholders are scrambling to reverse, or at least slow, the lake's decline. But their efforts have proven futile so far. In 2005, Lake Okeechobee endured an unprecedented spike in its primary pollutant, phosphorus, which averaged 240 parts per billion -- twice what the lake had averaged over the previous four years.

According to the most comprehensive study on Okeechobee in recent years, commissioned by the Audubon Society of Florida, researchers found nearly half of the 750-square-mile lake's bottom covered with "a thick layer of organic muck ... which contains an estimated 51,000 tons of phosphorus."

Ironically, Lake Okeechobee's potential killer is itself a known life-giver. Phosphorus is an abundant and widely used fertilizer for farms, golf courses and lawns. But it is also the main ingredient in a pollution cycle that begins with an explosion of nutrient-loving algae and ends with lifeless, oxygen-deprived water where the pungent smell of decay can induce tears in recreational fishers who have spent their lives on Okeechobee.

Hurricanes played key role
Add to phosphorus-laden runoff the insults of devastating back-to-back hurricane seasons that churned Okeechobee's bottom sediments into a dense cloud of suspended sludge. More than stir the lake's bottom, hurricanes Charley, Frances and Jeanne in 2004, then Wilma last year, shot massive slugs of stormwater into Okeechobee. The result was a massive pool of filthy water, so clouded with sediment that the lake's bottom grasses and marsh, essential habitat for fish, began dying. The problem was especially pronounced in the lake's littoral zones, where sunlight normally penetrates to the bottom, encouraging plant growth.

The Army Corps of Engineers also expressed concern about the high water pushing against the southern rim of Okeechobee's flood-protection structure, the Hoover Dike, and the possibility of a catastrophic flood should the dike break. A dike failure would dump billions of gallons of water into Florida's sugar-growing region, known as the Everglades Agricultural Area, and bury towns that dot the lake's south rim. Those towns -- Belle Glade, Clewiston and Pahokee -- had experienced devastating floods before, twice in the 1920s, prompting President Herbert Hoover to order construction of the 35-foot dike that now rings the lake.

Last year, with Wilma threatening to swell the lake to dangerous levels once again, the corps and the South Florida Water Management District accelerated discharges of Okeechobee's water down the St. Lucie and Caloosahatchee canals toward the coasts. The discharges, termed "pulses" by water managers, set off public opinion firestorms at the mouths of the canals.

Residents of Stuart and Palm Beach on the Atlantic Coast and Fort Myers on the Gulf Coast began seeing their estuaries collapse as Okeechobee's pollution-laden water mingled with tidal waters. From the banks of the normally vibrant St. Lucie River, complaints of rank odors, discolored water, and fish with lesions and other ailments began pouring into state and federal offices.

The response from elected officials was swift. Sen. Bill Nelson (D) toured the St. Lucie last August, declaring that Congress, the corps and other agencies must act decisively to stem the damage. He called for the passage of a new Water Resources Development Act (WRDA) to help the corps and other agencies move forward on critical infrastructure projects, including portions of the Comprehensive Everglades Restoration Act of 2000. So far, that has not happened.

Gov. Jeb Bush (R) also stepped up, pledging to spend $200 million over four years to address Lake Okeechobee's pollution crisis, saying "our quality of life and the economy depend upon a healthy lake" (Greenwire <http://www.eenews.net/Greenwire/2005/10/11/archive/10/> , Oct. 11, 2005). Bush's direct involvement follows the Legislature's passage in 2000 of the Lake Okeechobee Estuary Recovery Plan, which established ambitious targets for phosphorus loading and concentrations in the lake by 2015.

Most important, Bush pledged to reduce runoff pollution from cattle farms north of Okeechobee, historically the lake's No. 1 source of phosphorus and nitrogen. He also promised to work with the South Florida Water Management District and the corps to permanently lower water levels in Okeechobee, thus reducing flood risk to the Everglades Agricultural Area and allowing submerged grasses and emergent marsh areas to recover.

Bush also promised additional support for ongoing efforts to restore the Kissimmee River watershed north of the lake. The Kissimmee restoration project, authorized by Congress under the 1992 WRDA legislation, seeks to return the original hydrology of the river's floodplain, which once extended over thousands of square miles of prairie. The prairie, in turn, acted as a sponge, soaking up rainwater that was slowly released to the lake. At the height of the wet season, the Kissimmee floodplain stretched several miles across with water depths of only a few feet, mirroring the hydrology of the Everglades.

Since the passage of WRDA in 1992, the corps and the state have worked diligently to undo some of the damage wrought by the Kissimmee's channelization. It has restored bends to the river in some areas and worked to encourage land owners to "hold back" more water during the wet season so that Lake Okeechobee can naturally moderate its water levels and the corps can avoid harmful discharges.

But it still may not be enough.

'Knock out punch'
According to the Audubon Society's recent Okeechobee study, the lake's water quality began declining in the 1950s and '60s, when "modern agricultural methods called for draining land and applying large amounts of chemicals," including nitrogen and phosphorus, to make the land more suitable for pasture, field crops and dairies. Thus began the upsurge in phosphorus loading to Okeechobee that in three decades had raised lake concentrations from an average 40 parts per billion (ppb) to more than 130 ppb by the 1990s.

Also, in the 1960s and '70s, in order to reduce flooding and improve the region for farming and human habitation, the corps channeled the 100-mile-long Kissimmee River and dewatered its floodplain. The once meandering river that perennially overflowed its banks to flood the prairie was issued a new government designator that better reflected its new purpose: "Drainage Canal C-38."

On an afternoon drive through the Kissimmee watershed with Audubon's chief Okeechobee scientist, Paul Gray, evidence of 50 years of large-scale landscape alteration is stark. The skillet-flat region, which remains one of the premier livestock grazing areas in the eastern United States, is laced with drainage ditches, many of which lead to ponds or impoundments for cattle. Beyond the ponds standing water is scarce, except where the ditches merge into larger canals that usher water to the Kissimmee River.

During heavy or prolonged rains, the Kissimmee sends torrents of polluted stormwater into Lake Okeechobee, where already high phosphorus levels can double or even triple in a matter of hours. Such peak inflows, especially in the wet season, often force lake managers to open floodgates to the St. Lucie and Caloosahatchee rivers, effectively dumping pollution on the estuaries. Corps of Engineers' policy is to accelerate water discharges from the lake to the St. Lucie and Caloosahatchee canals as lake levels approach 16 feet. In both 2004 and 2005, lake height well exceeded 16 feet as hurricanes overwhelmed the system.

"At that point, it becomes a knock-out punch for the lake and for the coasts," Gray said.

While the lake and its downstream coastal estuaries are suffering with massive inflows of polluted water, the crisis poses equally devastating consequences for the Everglades, which were effectively severed from Lake Okeechobee when the government built the Hoover Dike and encouraged large-scale farming and human settlement on the south side of the lake.

Farm pollution at issue
Today roughly 670 square miles of Okeechobee's historic drainage -- an area only slightly smaller than the lake itself -- have been converted for sugar cultivation, and the region's muck soils grow upward of 20 percent of the nation's sugar cane, with most of the bounty shared by two large firms, U.S. Sugar Corp. and Florida Crystals Corp.

Sugar cane farmers, most of whom are contracted to the large processors, have long been targeted by environmental groups for the damage their operations pose to the Everglades, including the large-scale conversion and drainage of land that otherwise would carry water unimpeded to the marshes.

"There are a multitude of things to be worried about," said Joette Lorion Rice, a longtime Everglades activist and consultant to the Miccosukee Indians, whose ancestral lands lie in the heart of the historic "River of Grass." "But right now the biggest problem is that Lake Okeechobee has been so fouled by pollution that the water flowing into the Everglades is doing more harm than good."

The Miccosukees are part of a coalition fighting court battles to try to slow the onslaught of pollution, not only to the Everglades but to the lake itself. One key lawsuit, before the U.S. District Court in Miami, aims to put a stop to "backpumping" of excess water from sugar cane fields into Lake Okeechobee as a flood control measure. The practice, sanctioned by the South Florida Water Management District, has been mired in controversy over whether the pumping stations should be required to obtain federal pollution discharge permits.

In hearings earlier this month, plaintiffs' attorney David Guest argued that water managers' pumping of phosphorus-laden water back into Lake Okeechobee is a violation of the Clean Water Act. Moreover, he said, earlier courts have ruled that managers can pump water into the lake only under emergency conditions, not as a matter of normal operations.

The South Florida Water Management District, with the support of the sugar industry, has argued vehemently against the necessity of such permits, with one district board member asserting that, "Congress never intended for governmental entities to obtain permits for moving water for flood control and water management purposes."

Malcolm "Bubba" Wade, a senior vice president with U.S. Sugar and a key industry negotiator on Lake Okeechobee issues, characterized the lawsuit as another in a long line of grudge battles that environmental groups have waged against the industry since the 1970s.

Indeed, the perceived environmental damage caused by "Big Sugar," a pejorative suggestive of both the industry's large landscape imprint as well as its political stature in Tallahassee and Washington, is so ingrained among some Everglades activists that critics often overlook key facts that suggest the industry is a diligent steward of its piece of the Everglades.

For one, "Big Sugar" is regulated more than almost any other industry, farm or non-farm, operating in either the Okeechobee or the Everglades watersheds, Wade said. Among other things, sugar growers pay an annual 25 dollars-per-acre tax to help fund Everglades conservation programs, he said. And farmers also have adopted a strict set of "best management practices" related to the pumping and discharging of water that have greatly reduced pollution loads.

As for backpumping into Lake Okeechobee, Wade said the practice constitutes an increasingly small percentage of the lake's total inputs, down from 8 percent to 3 percent in recent years.

Pointing fingers at sprawling suburbs
A better target for stemming Okechobee's pollution may be well north of the lake, in the upper reaches of the Kissimmee watershed. Population pressure in the central part of the state has pushed development south from Orlando, where subdivisions now ring the chain of Kissimmee lakes, all of which are linked by canals and pumping stations.

Experts believe a growing share of Okeechobee's pollution may be traced back up the Kissimmee River as far as Orlando, which sits at northernmost point of the watershed. While much has been made of the environmental stresses posed by development along the Atlantic Coast from Palm Beach to Miami, Gray of the Audubon Society noted that metropolitan Orlando is encroaching even faster into the Okeechobee watershed, and new development there will have lasting implications for the Everglades.

"Acre-for-acre we know that urban development uses more phosphorus and other fertilizers than these agricultural areas do," Gray said.

Meanwhile, state and federal officials continue to search for the right combination of tools to steer Lake Okeechobee on a course to recovery.

"Florida is not going to sit back and let the lake die," said MacVicar, the environmental consultant. "That would be untenable. A number of rescue efforts are going to tried, and hopefully we can bring this thing back."