A billion-dollar coastal project begins in Louisiana. Will it work as sea levels rise?

NEW ORLEANS (AP) — Nearly $3 billion in settlement money from the BP Deepwater Horizon disaster that devastated the Gulf Coast and killed hundreds of thousands of marine animals is now funding a massive ecosystem restoration in southeastern Louisiana’s Plaquemines Parish.

The flat, sparsely populated land divided by the Mississippi River delta is marbled by bayous and bays. Farms, fishing camps and shrimp boats share the region with oil rig supply vessels and industrial storage. And it's about to host a vast undertaking meant to mimic Mother Nature: Enormous gates will be soon be incorporated into a flood protection levee.

The aim is to divert some of the river's sediment-laden water into a new channel and guide it into the Barataria Basin southeast of New Orleans.

If it works, the sediment will settle out in the basin and gradually restore land that has been steadily disappearing for decades. State coastal officials call it a first-of-its-kind project they are certain will work, even as climate change-induced rising sea levels threaten the disappearing coast.

Gov. John Bel Edwards called it the largest such ecosystem restoration project in the state's history. "Quite frankly I’m not aware of one on this scale any where in the country and they’re are few in the world that can match the size of this project,” he said at Thursday's groundbreaking.

Bren Haase, chair of Louisiana's Coastal Protection and Restoration Authority, estimates the project will build anywhere from 20 square miles (52 square kilometers) to 40 square miles (104 square kilometers) over the next 30 to 50 years.

The U.S. Army Corps of Engineers, which permitted the project last year, projected creating of as much as 21 square miles (54 square...