DELACROIX, La. — Rocky Morales is watching his small Louisiana town of Delacroix slowly melt into the water. The woods where he played hide-and-seek as a boy are gone. It’s all water and mud back there now. So, too, is the nearby marsh where townsfolk once trapped for muskrat, otter and mink.

Many of the fishermen who once lived here — his friends and relatives — have disappeared as well, fleeing behind the levees protecting New Orleans out of fear one more hurricane will send the rest of Delacroix into the sea.

Ten years after Hurricane Katrina ravaged the Gulf Coast — killing more than 1,830 people and causing more than $150 billion in damage in the nation’s costliest disaster — New Orleans has been fortified by a new $14.5 billion flood protection system. But outside the iconic city, efforts have lagged to protect small towns and villages losing land every year to erosion. And as that land buffer disappears, New Orleans itself becomes more vulnerable.

In the past century, more than 1,880 square miles of Louisiana land has turned into open water — an area nearly the size of Delaware. And the loss continues, with an average 17 square miles disappearing annually, according to the U.S. Geological Survey.

Cemeteries are disappearing into the Gulf. Entire barrier island chains, Andrew Jackson-era brick forts, Jean Lafitte’s pirate colony, lighthouses, bridges, roads, schools and entire towns have been washed away.