Huge reservoir rises in the Everglades

updated 8:48 a.m. ET May 7, 2008

IN THE EVERGLADES, Fla. - Around South Florida's vast sugar cane fields, where turtles grow to the size of basketballs and alligators own the marsh, the silence of the swamp is broken by the sound of rumbling trucks and explosions.

The earth-moving equipment and high explosives are laying the foundation for a mammoth construction project: a reservoir bigger than Manhattan designed to revive the ecosystem of the once-famed River of Grass.

More than a century after the first homes and farms took shape in the Everglades, decades of flood-control projects have left the region parched and near ecological collapse. Now crews are building what will be the world's largest aboveground manmade reservoir to restore some natural water flow to the wetlands.

Engineers "built this thing beautifully," said Terrence Salt of the U.S. Interior Department, referring to the flood-control systems that practically drained the swamp to make way for development decades ago. "But as we look back at it through the lens of our current 21st-century values and understanding, you get a different take on it, which leads to our restoration efforts now."

The wetlands once covered more than 6,250 square miles, but they have shrunk by half, replaced with homes and farms and a 2,000-mile grid of drainage canals. In the process, the Everglades has lost 90 percent of its wading birds. Other creatures are at risk, too, including 68 species that are considered threatened or endangered.

The reservoir, estimated to cost up to $800 million, is the largest and most expensive part of a sweeping state and federal restoration effort.

Most man-made reservoirs are built in canyons or valleys and use a natural water source such as a river to fill in behind a dam. This one will stand on its own, contained within earth-and-concrete walls much like an aboveground swimming pool larger than many cities. Planners hope to eventually double its size.

'Essential,' scientist says
Thomas Van Lent, a senior scientist with the Everglades Foundation, said the reservoir "is absolutely essential" to restoration efforts. But he acknowledges it will never return the region to its historical grandeur.

"There are parts you can restore completely, but you can't restore it all," he said. "It's probably unrealistic to expect Miami to move."

The Army Corps of Engineers, which is working with the state on restoration, recognizes the same limits.

"We're certainly never going to return it to the way it was 150 years ago," said the Corps' Stuart Appelbaum. "But we can do our best."

Water once flowed practically unhindered from the Everglades headwaters south of Orlando all the way into Florida Bay at the state's southern tip. But now when a hard rain falls, canals direct the overflow into the ocean to keep from inundating 5 million people who have settled in the area.

That's where the massive reservoir just south of Lake Okeechobee comes in. It will store up to 62 billion gallons of water that would normally be channeled out to sea and instead divert it into the Everglades at various times to mimic a more natural flow.

"We've developed about half of the Everglades, so we've got this very efficiently designed flood-protection system," Appelbaum said. Now engineers want to store that water so they "can put it back into the natural system to replicate what we lost when we did all the drainage."

21-mile levee
Bulldozers and dump trucks are removing 30 million tons of dirt and muck from the reservoir site, which will then be surrounded by a 26-foot high, 21-mile levee of crushed rock and compacted soil. The levee will also have a 2-foot-thick concrete wall built into it to reduce seepage and add stability.

Major construction began in 2007. When the reservoir is compete in 2010, the shorelines will be so far apart — 6 miles at the widest — an onlooker won't be able to see from one side to the other.

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