At first sight, the Florida Everglades are a disappointment. There are no forests, mountains or cascading rivers.

Just kilometre upon kilometre of sawgrass prairie, cypress and mangrove swamps, interspersed with occasional clumps of hardwood trees known as hammocks.

"The landscape is so flat. It's not scenic grandeur like the Rocky Mountains or the Grand Canyon. You could say that this is the first park established for its biological not its aesthetic value," says Rick Cook, a ranger at the Everglades National Park, which covers more than 600,000 hectares [1.5m acres].

The wetlands are a United Nations world heritage site; international recognition perhaps but little help in the face of rampant urban development. The Everglades, South Florida's green heart, are threatened, perhaps even dying.

Micro-ecosystems

The ecosystem begins at Lake Okeechobee, south of Orlando. From the lake, water flows shallowly and almost imperceptibly south-westwards through the sawgrass, eventually discharging into Florida Bay.

The water flows southerly into Florida Bay

Any slight elevation of land creates a new micro-ecosystem, full of plants, animals and birds, who regulate their breeding habits according to the wet and dry seasons. Or at least, that is how it used to be.

South Florida's subtropical climate is a magnet for people. At first, they settled along the coast, but increasingly they moved into the Everglades, clearing what they saw as worthless swamp for housing and agriculture.

Nature was hard to tame though, and after several disastrous floods, the authorities embarked on a vast flood control project in the 1940s.

Depleting natural wells

Canals and dykes criss-cross South Florida, regulating the flow of water. In the wet season, water is discharged through the canals into the sea or released into the Everglades National Park. In the dry season, pumps suck water out of underground aquifers, depleting these natural wells a bit more each year.

The result has guaranteed water for urban and agricultural development, but at a huge cost to the environment.

Now, half of the Everglades has been lost, and along with it much of the fish and animal populations. Wading birds, who are very susceptible to changes in water levels, have been literally decimated.

Government and environmental agencies agree that South Florida, whose population could increase from the current 5 million to more than 15 million in the next 30 years or so, is at a crucial point.

The existing flood control system has not only harmed the environment, but it pumps more than 8 billion litres of water out to sea a day - water that is needed by an ever-growing population.

Saving the Everglades

The solution being proposed is an entire re-plumbing of the system. The United States Army Corps of Engineers, which created the original flood system, has been working with several other agencies and organisations to draw up a 25-year, $8bn plan to save the Everglades and guarantee South Florida's water supplies into the middle of the next century.

The Cape Sable Seaside Sparrow is on the brink of extinction

This complex project essentially aims to remove some of the canals and dykes to create a more natural flow through the Everglades; at the same time, hundreds of underground storage wells would be built to store water for use in the dry season.

It is a bold and risky plan, relying on untested technology. But Colonel Joe Miller of the Army Corps insists that they will proceed carefully.

"Adaptive management is crucial. We're starting with pilot projects and we'll learn as we go along, " he said.

But learning on the job is not good enough for some South Florida residents, who are questioning not only the plan's concept but its cost.

The US Congress will decide in July whether to authorise federal funding for the Everglades restoration plan. Approval seems likely, but that will merely signal the start of a long battle over how to proceed with restoring an ecosystem unique to not only the United States but the world.