In the 20th century the U.S. Army Corps of Engineers drained much of Florida's Everglades to prepare the wetlands for development. At the dawn of the 21st century, Congress directed the corps to reverse much of that work and restore the Everglades to a more natural condition.

It's proving to be a very slow process.

Last week, the corps approved a central element of the restoration plan: a $2 billion series of engineering projects designed to collect water around Lake Okeechobee, in the center of the Everglades, and channel it south into the rest of the wetlands. The corps had hoped this Central Everglades Planning Project would be approved and funded by Congress quickly.

But Congress is operating on its own schedule. On May 22—the day before the corps took action—the Senate passed and sent to President Obama a bill funding water projects nationwide. Although it includes some money for the Everglades, it was passed before the Central Everglades Planning Project was finalized.

Now it could take years before Congress passes another water bill—it's been seven years since the last one—and projects that are critical to the restoration of Florida's famous swamplands could face long delays.

Proponents of restoration argue that more urgency is needed. Dawn Shirreffs, senior policy adviser for the Everglades Foundation, an advocacy group, hopes the corps's approval of the Central Everglades Planning Project will spark Congress to revisit the issue sooner.

The corps concurs. "We're at a key point for gaining and keeping momentum," says Kim Taplin, its Central Everglades branch chief.

A River of Grass

Florida's coasts were among the first places explored by Europeans in the 1500s, but the newcomers were reluctant to venture far into the seemingly endless, swampy interiors. The vast expanse of subtropical wetlands—the saw grass marshes, mangrove forests, and dense stands of tropical hardwood trees called hammocks—were not fully charted until the 1940s, long after the rest of the East Coast was mapped.

The idea to drain the Everglades was brought up as early as 1837. But it wasn't until the 1930s that engineers began a 40-year effort to build 1,800 miles of canals. That construction, mostly done by the corps, included projects that diverted water from Lake Okeechobee.

Named after a Creek Indian word meaning "big water," Lake Okeechobee was the heart of the Everglades. In the centuries before engineers arrived, the lake would flood its banks and the excess water would follow a gently sloping grade south in what is called a sheet flow.

This created a 60-mile-wide "river of grass" that became the iconic image of the Everglades.

But unpredictable flooding wasn't good for development. Lake Okeechobee was dammed in the 1930s, and canals were built to direct excess water to the Gulf of Mexico and the Atlantic.

Land speculation came in waves, with developers putting ads in Northern newspapers touting South Florida's warm temperatures during the winter months. Buyers purchased swampy lots sight unseen.

View Images An alligator swims in the dark water of Everglades National Park. PHOTOGRAPH BY KAREN GLASER

Depleted Aquifers

The population in Florida, much of it concentrated in the south, swelled from two million before World War II to six million in 1965. The state prepared more new lots for homes in the 1960s than the rest of the country combined.

The draining worked too well. In dry years no water at all flowed south to the Everglades and the aquifers it replenishes. This includes the 4,000-square-mile Biscayne Aquifer, which serves as the main water source for much of South Florida.

As populations swelled and the Everglades diminished, salt water seeped into depleted aquifers. In the 1970s, after an especially dry year showed how precarious the water situation had become, Florida governor Reubin Askew said that the southern part of the state could become "the world's first and only desert which gets 60 inches of annual rainfall."

A 30-Year Plan

The fight to save the Everglades was already well under way by then. Marjory Stoneman Douglas, an activist and journalist, wrote in 1947 that the region was in its "11th hour." Douglas identified the wetlands as a unique place worth saving, not a wasteland to be paved over.

The activism of Douglas and others slowed development and allowed the creation of Everglades National Park, but the depletion of wetlands continued. One of every three Floridians relies on the Everglades for water, yet the wetlands today are half the size they were at the beginning of the 20th century, and they continue to dry up.

Concern has been growing. In the 1990s local residents, farmers, environmentalists, and people from hotels and other businesses involved in tourism banded together to help persuade Congress and the Army Corps of Engineers to act.

In 2000 Congress passed a 30-year plan to save the Everglades. It's the biggest and most expensive restoration ever attempted: a $12 billion scheme to backfill canals, create reservoirs, eradicate invasive species, and improve water quantity and quality in an 18,000-square-mile area that covers 16 counties, from Kissimmee to the Keys, and from the Gulf of Mexico to the Atlantic Ocean.

The project was lauded as proof that large-scale ecological damage can be reversed. But a 2012 study from the U.S. National Research Council pointed out that the first projects—including storm-water treatment plants and the redirection of a river to its original path—were addressing issues only on the peripheries of the wetlands.

So the corps, with input from a wide variety of groups, including environmental organizations, bass fishermen, and property owners, worked on a plan to restore the central part of the ecosystem.

The result was the Central Everglades Planning Project, which will redirect water from Lake Okeechobee to the Everglades, backfill 19 miles of canals, and restore the sheet flow to one million undeveloped acres, among other things.

A Dire Situation

The project is considered more vital than ever, in part because another factor has gained importance in recent years: climate change, which poses a severe threat to South Florida's coastlines.

The latest National Climate Assessment report, on May 5, painted a dire situation.

Sea levels on Florida's coasts have risen five to eight inches since the 1960s. Canals built in Miami to discharge storm water to the Atlantic have been closed because the ocean would rush in if they were open. And Miami Beach floods during high tides when the moon is full.

Everglades restoration, by adding fresh water to the area, will help prevent salt water from intruding on the aquifers. The project will also stave off peat collapse (when normally damp soil dries out and loses volume), which lowers elevation and lets the ocean encroach inland.

Jayantha Obeysekera, the chief hydrological modeler for the South Florida Water Management District, calls the restoration "one of the best strategies for climate change and sea level rise."

A corps study shows that on a 50-to-100-year time line that takes into account climate change, land loss in South Florida will be up to 50 percent less with Everglades restoration than without it.

And the plan could still be tweaked to improve that ratio.

View Images Birds circle and alight on Lake Okeechobee, seen here in May 2007. PHOTOGRAPH MARc SEROTA, GETTY IMAGES

Conflicting Concerns

Eric Bush, the corps's policy chief overseeing the Central Everglades plan, said discussions are under way about how to reset priorities with climate change in mind.

But the discussions aren't easy, because different parties have conflicting concerns. Environmentalists want more water for the wetlands, for instance, but water also needs to be diverted to residential purposes to accommodate further growth.

If previous discussions on Everglades restoration projects are any indication, compromising on climate change will be tricky. "I like to say the Everglades is a full-contact sport," Bush says.

And as debate continues—in Florida and in Washington, D.C.—progress is excruciatingly slow. To date, only one of 68 projects listed in the overall restoration plan has been completed. Other work will proceed, but much of the restoration depends on future funding.

Congressman Bill Shuster of Pennsylvania, the chairman of the House Transportation and Infrastructure Committee, issued a statement that supported revisiting the water bill every two years.