TOM BEARDEN: Ken Rice and Laura Brandt catch a lot of alligators. In a year they will snare about 200 alligators, tape their mouths shut, measure and weigh them, and finally mark them before release. It's part of an ongoing scientific study of the health of the Florida Everglades.
LAURA BRANDT: We use a combination of the length and the weight measurements and tail girth as an indicator of how fat or how healthy the animal is.
And so an animal that was in poor condition, there would be very little fat here, and this might be indented. And so we can use that as kind of an indicator of what is going on in the environment that the alligator is living in.
LAURA BRANDT: One, two, three.
TOM BEARDEN: Alligators are one measure of whether a massive, multi-billion dollar state and federal restoration project now underway will eventually be successful in salvaging what is left of the Everglades.
KEN RICE, Biologist, U.S. Geological Survey: We're trying to look throughout the whole Everglades ecosystem, and what we're trying to do is develop a tool so that in the future, after restoration of the Everglades begins, we can start judging whether or not restoration is working.
So if the animals aren't getting more healthy or in better condition, then we know that restoration isn't occurring.
TOM BEARDEN: The vast Everglades system is called the "river of grass." It's a unique ecosystem that is both wet and dry, supporting alligators, wading birds and a myriad of other species.
And the whole thing is dying because flooding was once a life-threatening problem in South Florida. In the 1940s, the Army Corps of Engineers straightened rivers and diverted stream flows away from the Everglades and into the ocean. That stopped the flooding.
This enormous plumbing system also provided South Florida's rapidly growing coastal cities with drinking water, but the projects also killed half the Everglades. The flow of fresh water through the wetlands dropped 70 percent.
As a result, alien plant species began to crowd out native trees and grasses, and small islands that provided homes for animals disintegrated. Vast flocks of birds that once darkened the skies disappeared.
The water quality also changed as a result of agricultural runoff, and peak flows vital to wildlife were severely altered. Duke University biologist Stuart Pimm:
STUART PIMM: What this image shows is the is a natural flow to the water in the Everglades. It comes down in this curved flow that we call "the swoosh." What's wrong with the Everglades is that that flow has been interrupted.
TOM BEARDEN: People have long known that something had to be done if the remaining Everglades were to be saved, but for decades the various competing interests couldn't reach a compromise approach.
Finally in 1992, Congress directed the U.S. Army Corps of Engineers to develop a comprehensive plan.
A coalition of environmentalists, scientists, engineers and other groups have developed a 30 year, $8 billion plan funded by both state and federal tax dollars. Corps engineers Stuart Applebaum and Dennis Duke are the program's managers.
DENNIS DUKE: The scale of the project is unprecedented in the Corps of Engineers in terms of a civil works, environmental restoration project. This is the largest environmental restoration project we've ever embarked upon.
STUART APPLEBAUM: We're trying to restore hydrologic characteristics that made the Everglades unique. If we do that, we believe that we'll restore the landscape, habitats, and then we'll get the birds and animals back.
TOM BEARDEN: The first order of business was to restore the Kissimmee River south of Orlando, at the very northern end of the historic Everglades system.
SPOKESMAN: Welcome to downtown to Kissimmee restoration. This is it. This is what I was talking about that used to be all pasture land.
TOM BEARDEN: The river had been straightened in the 1960s to control flooding. Corps Engineer Frank Mohr has spent the last five years returning the river to its natural, meandering path.
This facilitates the flow of water to areas that were once cut off from hydration and help to restore what was the north end of the Everglades system.
Mohr says the land is so flat that it took a great deal of care to re-contour what had been pastureland back into a viable river basin.
FRANK MOHR: It was very important to get the grades correct. And picture it out here. Excavating out, you get one shot to get it to the right elevation. There was no going back.
Again in Florida, the gradient for water drop is so slight, that it was very critical that we do it that way.
TOM BEARDEN: Getting it right was essential to restoring the naturally slow flow of the water, which the Corps hoped would allow the ecosystem to restore itself, something they believe will happen when the proper flow is restored to the larger Everglades.
Duke says the plan is working.
DENNIS DUKE: The results we're seeing, in terms of restoration or recovery of the system, are astounding at this point -- far beyond our predictions in terms of the wildlife coming back, the fisheries coming back.
The project was constructed not that long ago, so there's a lot more recent data on what... how the system existed prior to the canal dredging, and now we're seeing a recovery that equals that in this area where we have actually completed restoration.
TOM BEARDEN: The restoration plan also calls for the construction of new aboveground and underground reservoirs to store water to better regulate runoff into the wetlands.
But something also has to be done to restore water quality. The old flood control projects allowed vast areas of land south of Lake Okeechobee to be used for agricultural purposes.
But the natural Everglades environment is nutrient-poor, requiring farmers to use fertilizer. Rainfall washes that fertilizer, mostly phosphorus, into the remaining wetlands to the South.
That spurs the growth of invasive, alien plants and crowds out local species.
TOM ARMSTRONG: On the submerged, aquatic vegetation, we can scrape off algae.
TOM BEARDEN: U.S. Geological Survey chief scientist Tom Armstrong showed us a water quality test site in the Loxahatchee National Wildlife Refuge, which is located inside the Everglades.
They're using plastic tanks to see how various levels of phosphorus affect a critical algae called periphyton.
TOM BEARDEN: What have you learned so far?
TOM ARMSTRONG: Well, the best thing to do is to look inside the tank, and the proof is in the pudding. Inside the tanks, there is no periphyton. There is none of that nutrient which is necessary for life to really thrive here in the ecosystem.
The reason we don't have the algae in the tanks is because the levels of phosphorus that we've added, in this case to the tanks, prohibits or inhibits the growth of the nutrient material.
TOM BEARDEN: Armstrong says periphyton is the building block of the entire Everglades food chain, that small creatures eat it and in turn provide food for larger animals.
Getting phosphorous out of the water is one of the project's most important challenges. South Florida water management engineer Gary Goforth describes one effort.
GARY GOFORTH: We have built levees, canals, pump stations and other water control structures and are using it to capture the runoff from the agricultural tributaries.
The water passes through large treatment cells that are full of vegetation. As the water passes through the treatment area, their phosphorous content is decreased. It is picked up by the soil; it's taken up by the vegetation.
TOM BEARDEN: This large area under construction is a variation on the theme. After it's flooded, it will have a mat of periphyton, phytoplankton and other microscopic organisms at the bottom that engineers hope will remove even more phosphorus that the existing treatment cells.
Phosphorus causes other problems. It provides food for exotic plants. In Everglades National Park, the National Park Service is using a radical approach to eradicate one such species.
What looks like a strip mine is actually a massive effort to kill Brazilian pepper trees. Originally imported by homeowners as ornamental plants, the trees have infested large areas of the park.
The Park Service tried ripping them out, but they just grew back because the phosphorus fertilizer remained in the soil.
A 14-year, $75 million restoration project is now underway. They use bulldozers to scoop up the contaminated soil and isolate it in large mounds that visually mimic the natural islands of the Everglades. Dan Kimball is the acting park superintendent.
TOM BEARDEN: To a layman, this seems pretty extreme.
DAN KIMBALL: Well, this is what it takes. This project is really based on good science. We looked at a lot of other alternatives, leaving things in place, trying mechanical treatment, trying chemical treatment and we really, through good science, decided this was the kind of action that was needed to come in and take a rather aggressive action, move a lot of materials to restore the natural system.
TOM BEARDEN: The Park Service points to previously treated areas like this as proof that the concept works. Scientist Michael Norland says the natural habitat rapidly reestablished itself after treatment.
TOM BEARDEN: So this is an area you've already worked on?
MICHAEL NORLAND: Yes, this is complete.
TOM BEARDEN: What are we seeing here?
MICHAEL NORLAND: Saw grass: The native tuber of grass, the plant that everybody thinks of when they think of the Everglades.
TOM BEARDEN: And this came back on its own.
MICHAEL NORLAND: Yes, it did.
TOM BEARDEN: So you don't have to replant?
MICHAEL NORLAND: We don't replant any of these areas that we're going to be seeing as far as the restored sites.
TOM BEARDEN: How rapidly will this area re-vegetate?
MICHAEL NORLAND: Within a year, we would meet our permanent requirements as far as wetland species on site.
TOM BEARDEN: But not everyone is convinced that the comprehensive restoration plan is based on good science. Duke University biologist Stuart Pimm says many of the measures being taken -- the reservoirs, the treatment areas, for example -- are untested.
STUART PIMM: Any engineer will tell you it's okay to ask for one miracle, but asking for several is a bit risky. And to get the water back into the system along the lines of this plan, is going to require a lot of engineering miracles.
TOM BEARDEN: Specifically Pimm points to this road, the Tamiami Trail, which connects Miami and Tampa. It basically bisects the state.
Pimm says it acts like a dam, and says the roadway will have to be elevated to allow water to flow beneath it and into the national park. He thinks this should be one of the first projects rather than one of the last.
But project planners say they are looking at different ways to get the flow going through the Tamiami Trail.
One option, rather than raise the whole road, is putting in dams like this one. Pimm says that proves this so-called restoration project is really more about providing drinking water for the burgeoning population of South Florida.
STUART PIMM: I think anybody who looks at this will feel that this is more of a water project than a conservation project. That's okay, if it's been sold as a water project. I live in South Florida part of the year. I pay taxes here. I need water.
But on the other hand, if this is being sold to the U.S. taxpayer as a ecological restoration, then we ought to get some money for ... we ought to get some restoration for our buck.
TOM BEARDEN: Project managers like Stuart Applebaum acknowledge that some of what they're doing breaks new ground and that results may be unpredictable. But he says the Corps is prepared to adapt as the project progresses.
STUART APPLEBAUM: We have models, we have computer tools, but obviously, the big key is how will it ... how will the system respond physically by making these changes.
And so that leads to a lot of the work that we're doing now called adaptive management, where we're going to monitor ... establish baselines, monitor conditions as we implement some of the restoration projects and make sure that they respond in the way we predict.
If it doesn't respond the way we predict, then we need to understand why not, and perhaps make changes in the plan as we go.
TOM BEARDEN: This fall, the Everglades restoration effort had a bit of setback, as the area was hit with three hurricanes. Scientists have found a loss of some vegetation and some damage to water treatment facilities.
They are continuing to study the impact of the storms on the system. Project managers believe that funding delays from the federal and state governments have pushed the restoration plan two years behind schedule.
Thus scientists say it may be 20 years before they know whether the comprehensive restoration plan will save the remaining Everglades.