WATERMARK.(Leeville, Louisiana)

Once the Mississippi River's main outlet, Bayou Lafourche--pronounced "la-foosh"--is now a channel barely wide enough to accommodate two shrimp boats heading in opposite directions. Its waters are slack and brown and salty, so much so that people who drink them--and many who live along the bayou do--complain that they sometimes taste like baking soda. The bayou wends its way south and east from Donaldsonville, Louisiana, through Thibodaux and Lockport and Cut Off, past citrus groves and shotgun houses and subdivisions eating into the sugarcane fields. Eventually, it empties into the Gulf of Mexico. Follow it almost to the end and you get to Leeville, a town that has spent most of the past century disappearing.

Leeville was settled by refugees, or, to use a less contested term, flood victims. On October 1, 1893, a hurricane wiped out the area's main settlement, Caminadaville, which sat on a spit of land bordered on three sides by the Gulf and on the fourth by swamp. Nearly half of Caminadaville's inhabitants perished in the storm, most by drowning, some when the buildings they had taken refuge in collapsed. Father Pierre Grimaux, the local parish priest, who rode out the disaster in the upper story of the presbytery, reported that "out of two hundred and fifty houses, only four remained." Survivors sailed up the bayou in their damaged canots and began buying land from an orange-grower named Peter Lee, who was selling plots for $12.50 each. For sixteen years, they fished, planted rice, and held fais do-do dancing parties in homes with covered verandas. Then, in 1909, the Leeville Hurricane struck. (A contemporary newspaper account described survivors of that storm subsisting on drowned rabbit.) Six years later, a third hurricane forced residents to flee north once more. According to local legend, the storm surge carried one house from Leeville nine miles inland. The owner simply bought the plot underneath it and moved back in.

In the nineteen-thirties, Leeville rebounded briefly. Oil was discovered in the area, and by the end of the decade there were ninety-eight producing wells in town. The pay was good and regulation nonexistent. Blowouts routinely rained sulfur and brine onto the houses, into the cisterns, over the trees. Tin roofs corroded and vegetable gardens shrivelled up. When the wells ran dry, oil production moved offshore and Leeville was again deserted. There were no more jobs, and the town itself had begun to wash away. Where once men in straw hats picked oranges and harvested rice, today there is mostly open water.

A few months ago, I went to visit the remains of Leeville with Windell Curole, the director of the South Lafourche Levee District. Curole, as it happens, is a descendant of Peter Lee, and also a member of a swamp pop group that calls itself the Hurricane Levee Band. He is a trim man of fifty-four, with thick gray hair and dark, deep-set eyes. Seven of his eight great-grandparents grew up in Caminadaville, and three of his four grandparents lived in Leeville. Curole and his wife are raising their two children in Cut Off, thirty-five miles from the coast.

"That movement of my family reflects the communities of southern Louisiana," he told me. It was a dull autumn day, threatening rain that never came. "We have retreated, and we continue to retreat." As we made our way south along the bayou, Curole kept pointing out landmarks from his childhood. "That's where my grandfather's trapping camp was," he said, gesturing toward a stretch of boggy marsh. "When I was a baby, I could sit down in the front yard and not get my pants wet. When my mama was a kid, you had oak trees." Curole receives checks for an oil lease on a plot that he inherited from his grandparents. The plot is now submerged. In Leeville, we passed a bait shop, a gas station, and a cluster of mobile homes perched, like birds' nests, on narrow wooden pilings. We wandered down to a dock, which had a view of one of the last remnants of the old town--a cemetery. Leeville's dead had not been buried but entombed in vaults. Waves lapped at the caved-in bricks. A porpoise jumped out of the water, then slipped back in.

Five thousand years ago, much of southern Louisiana did not exist. A hundred years from now, it is unclear how much of it will remain. The region, it is often observed, is losing land at the rate of a football field every thirty-eight minutes. Alternatively, it is said, the area is shrinking by a large desktop's worth of ground every second, or a tennis court's worth every thirteen seconds, or twenty-five square miles a year. Between 1930 and 2000, some 1.2 million acres, an area roughly the size of Delaware, disappeared. Hurricanes Katrina and Rita stripped away an estimated seventy-five thousand acres--a loss as big as Manhattan and Brooklyn combined. The U.S. Geological Survey has published a map illustrating the process. Areas that have already vanished appear in red, and areas that are expected to vanish by 2050 in yellow. On the map, the southern coast looks as if it were on fire. According to the U.S. Army Corps of Engineers, "The rate at which Louisiana's land is converting to water is probably the fastest in the world."

The signs of this impermanence are most obvious at the ends of the bayous, where the border between land and sea is changing so quickly that no one really bothers to keep track of it anymore. But, once you start looking, those signs can be found just about everywhere. All across southern Louisiana, there are groves of dead cypress trees, known as ghost forests, which have been killed off by encroaching salt water. On the eastern edge of New Orleans, the Mississippi River-Gulf Outlet Canal--MR-GO ("Mister Go") for short--provides a shortcut for shipping. When it was completed, in 1965, it was five hundred feet across; now it is more than three times as wide. Then, of course, there's the city itself. Those neighborhoods, like Lakeview and the Lower Ninth Ward, which lie several feet below sea level are still essentially deserted.