Some scientists say it's an exciting "start". We take a boat to see the results. At the moment, we're whizzing down a channel about a few miles downstream from Caernarvon.

Denise Reed spends a lot of her life in these wetlands: she studies them for Louisiana State University. Reed would make a great scout leader—she's got no-nonsense hair, an infectious smile, and she forges through the grasses on this wetland like she's leading an expedition.

"We're going to go over to see some marsh over there—by those trees." Reed says. "And that's where we're going to see how the freshwater, the nutrients and the sediments coming out of the diversion structure are revitalizing the marsh. So we're gonna go see. It's right over on the other side there ... Look at all this wonderful green, you know, there's nice big growth on these plants."

Tracing the effects of the Canaervon. Photo: William Brangham/NOW with Bill Moyers

Reed says if we had walked here before they started the Caernarvon project, it would have felt completely different. This wetland was sick back then, and when wetlands are sick, the soil gets all mushy and turns into open water. But now we're walking on solid ground.

"You look at those ponds over there in the distance," Reed explains, "you see how the grass is gradually moving in and filling in. You can see that just here, you can see that grass growing out into the middle of this area. This would have all been bare. What is land loss? Land loss is marsh turning to open water. Here we've got open water in ponds filling in and becoming marsh. A lot of people think it's hopeless down here in coastal Louisiana, but just coming down here and looking at this makes us believe that we can do this."

But these changes have disrupted some people's lives. The problem is, the minute you put your finger on a map and say, 'Let's tinker with nature here, let's mimic the old floods there,' chances are that you might flood somebody's backyard. Or you'll disrupt the bays and inlets where George Barisich does his fishing.