France Moves to Save an Icon From Sediment and Sea Grass

The island and abbey have survived at least 13 major fires, several cataclysmic collapses, numerous Viking and Protestant invasions and 70 years' use as a prison after the French Revolution. It was the only part of Normandy that was never occupied by the English during the Hundred Years' War (1337-1453). Its perseverance has made it one of the most enduring symbols of French national identity, visited by as many as 30,000 tourists a day in the summer high season and 3 million a year overall.

According to Beaulaincourt, all bays undergo a natural silting process when incoming high tides deposit debris that outgoing tides are not strong enough to remove. The process is particularly pronounced in the Bay of Mont-Saint-Michel, where local lore has it that incoming tides travel as swiftly as a galloping horse.

The natural silting problem here was exacerbated by human activity, Beaulaincourt said.

First came Dutch engineers, who at the behest of the Normandy government built a series of canals in the 19th century to reclaim land along the shore for poor farmers. Then came the construction of the causeway to the island in 1879 at the mouth of the Couesnon River, stopping the free flow of water around the island and accelerating the buildup of silt and the rise of the seabed.

Five years after the causeway's completion, the author Victor Hugo saw the future and wrote: "The Mont-Saint-Michel must remain an island. We must save it from mutilation!"

Today, Beaulaincourt said, the bay around the island is losing 50 acres a year to spreading sea grass.

Under the project, the lower part of the Couesnon River will be dammed, and water will be allowed to flow into it at high tide, backing up into a reservoir. The dam gates will be closed and, after the tide recedes twice daily, opened again, spewing 53 million cubic feet of water into the bay around the island and flushing away the sediment.

After 10 years of this, he said, the seabed in the vicinity of the island should be about 28 inches lower than it is today, returning about 125 acres of marshland to its original state as tidal flats. Mont-Saint-Michel would remain an island, surrounded by a large expanse of water at high tide for 153 days a year, or about three times more often than it is now.

Those calculations are based on experiments with a 9,700-square-foot model of the project in Grenoble, with the results confirmed by a team of international experts, Beaulaincourt said.

But many people on the island are skeptical.

"It's just to remove the cars -- I don't buy the whole ecological argument" about saving the island, said Bruno Tardif, a snack bar manager who has worked on Mont-Saint-Michel for 30 years and is one of about 1,000 people who commute to work from nearby coastal towns. Like other vendors, he appeared mostly concerned that new businesses would develop around the proposed parking lot on the mainland, siphoning commerce from the island.

"It's the will of humans to reclaim land, and now, like a yo-yo, they are doing everything they can to put it back into the sea," said Alain Noslier, 55, a tour guide. "But Mont-Saint-Michel is striking geographically, biologically, historically and religiously, and if it goes inland permanently, it will lose its character."

Brother François, who heads a group of six brothers and five sisters from the Monastic Fraternities of Jerusalem who conduct services in the abbey, said Mont-Saint-Michel was laden with powerful religious symbolism that is important to protect -- the mountaintop, the story of the archangel's appearance, the sand flats where pilgrims wander, waiting for the parting of the sea at low tide.

"In the first verses of Genesis, it says, 'In the beginning the earth was empty, a blur, and the winds of God were blowing and turning upon the water,' " creating an indistinguishable mass of earth, sky and sea, he explained, standing on a terrace outside the abbey. He motioned to the west, where a gray sunset at low tide was reflected on pools of water and sand flats stretching for miles to the ocean. "That's it."

Researcher Corinne Gavard contributed to this report.