Saving The Everglades

Restoration: An ambitious environmental project is rife with risks and uncertainties.

Medicine & Science

November 24, 2003|By Heather Dewar | Heather Dewar,SUN STAFF

The most ambitious environmental experiment in history has begun on a South Florida tract where two Baltimore brothers once planned a sun-drenched retirement town.

In October, bulldozers moved the first dirt for a 30-year, $8.4 billion effort to revive Florida's dying Everglades. The site: a ghost subdivision called Southern Golden Gate Estate that was once the centerpiece of a development empire run by Leonard and Julius "Jack" Rosen.

The Rosens bought nearly 100 square miles of saw grass and cypress trees in 1958. They dug 48 miles of canals, built 290 miles of roads and sold lots to more than 50,000 buyers. But their plans collapsed and their Gulf American Land Co. went bankrupt in 1979. The abandoned development, now stripped to bare rock, became a popular landing site for drug-smuggling planes.

The property belongs to the government now, and state and federal planners chose the spot to jump-start the Everglades restoration by filling in seven miles of canals. They aren't sure what else it will take to grow cypress trees and saw grass there again, so they're designing a plan to heal the tract as they go.

Southern Golden Gate is the Everglades' story in miniature. Between the 1860s and the 1960s, private developers, the state and the federal government crisscrossed the southern half of Florida with canals.

A huge Army Corps of Engineers drainage project, completed in the 1960s, converted a mosaic of saw-grass prairies, cypress swamps, rivers, pine forests and tropical "tree islands" into flat, dry land for cities and farms. The Everglades shrank to about half its original size, lost 90 percent of its natural water supply and began dying of thirst. Today it is home to 68 endangered or threatened plant and animal species.

Now the Corps and its partner, the South Florida Water Management District, have designed a plan that would save most of the remaining Everglades by "getting the water right," as restoration scientists say. That means a balancing act: providing more water for the environment while setting aside enough for the region's booming cities and farmers who cultivate 100,000 acres of converted Everglades land.

To accomplish that, engineers must capture the rainfall that once spread gradually across the land, but now flows through the canals and out to sea. That water would be stored and released on a timetable that matches the Everglades' natural cycle of wet and dry seasons.

There are more than 40 engineering projects in the restoration plan - many based on untested theories about how the Everglades once worked, computer models that lack key information, or technology that has never been tried on a grand scale. Scientists acknowledge that it's a huge experiment, and expect to alter the plan many times before they finish the restoration work, around 2030.

"There are whole categories of uncertainties. They pop up everywhere," said John Ogden, chief environmental scientist for the restoration team.

"We had teams of scientists who created working hypotheses about why the natural system went bad," Ogden said. "This plan we took to Congress, for $8.5 billion, assumes the hypotheses are correct. And we know some of them are not correct, and some of them are kind of correct, and some are right on the money. But we don't know which ones are which."

The uncertainties start with the first step: a system to store water. Planners say they don't have enough open land to hold all the water in reservoirs. Instead they plan to build a network of wells, pump the water 3,000 feet underground and store it there for up to two years.

Some cities use this technique, called aquifer storage and recovery, to store drinking water. Las Vegas has 50 such wells that can store 80 million gallons a day. But the Everglades plan calls for 330 wells that can hold 1.6 billion gallons of water a day - about 150 percent of New York City's daily water consumption. No one has tried to store that much water in deep wells before.

Engineers want to pump the rainwater into the Floridan Aquifer, a spongy layer of limestone that holds brackish water. The Floridan Aquifer is in a precarious position: above it are surface aquifers that provide South Florida's 6.5 million residents with their water supply. Below it is another layer of rock where several cities dump their sewage in even deeper wells.

The Everglades plan assumes that the rainwater pumped into the Floridan Aquifer won't mix with the sewage below or the drinking water above. The new water can't be used for restoration if it absorbs salt from the surrounding water, since most Everglades plants and animals need fresh water. So the plan assumes that about one-third of the rainwater would mix with salty water and be lost.

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