(7 of 10)
There is one anti-erosion scheme, however, that can be effective: beach nourishment, which simply involves replacing sand that has washed away. Between 1976 and 1980, a ten-mile stretch of Miami Beach was rejuvenated with a brand-new, 300-ft.-wide beach. Oceanside, Calif., has struggled for more than 40 years to maintain its sandy beaches, ever since the creation of a boat basin at nearby Camp Pendleton during World War II interrupted the flow of sand down the coast. More than 13 million cu. yds. of sand have been dredged from offshore or trucked in from nearby rivers to replenish the Oceanside beaches.
Beach nourishment, however, is expensive. Just off the southern tip of Key Biscayne, Fla., an Army Corps of Engineers' hydraulic pump ran 24 hours a day, from mid-April to early July, sucking up sand from the ocean bottom and piping it to the beach half a mile away. By the time the dredge had finished, it had moved some 400,000 cu. yds. of sand at a cost of $1.55 million, much of it from the pockets of local businesses. In the early 1980s, the Army Corps brought in sand to widen the dwindling strip at Wrightsville Beach, N.C., by 200 ft., as well to construct and regrass new dunes. Price tag: $2.95 million. That is small change, however, compared with a program begun in 1976 for the New York City Rockaway beach project. Total cost for the twelve-year, 11.5 million-cu.-yd. project: $52 million in federal, state and city funds.
But even beach replenishment is a temporary measure. At the sprawling resort complex of Myrtle Beach, S.C., the community had little choice but to haul in 854,000 cu. yds. of new sand along ten miles of beach that had dwindled to a 10-ft. width in places, creating a glistening 100-ft.-wide strip at high tide. Ex-Mayor Erick Ficken says the community will be paying for the $4.5 million project over the next ten years. Naturally, he wonders, "How long will it last?" There are no guarantees. John Weingart, director of coastal resources for New Jersey's department of environmental protection, recalls one of that state's first replenishment projects. The 2 million-cu.- yd., $5 million nourishment of the beach at Ocean City was unfortunately timed; it was completed just before the stormy fall season. "Within ten days of finishing," he says, "we had several really bad local storms. Over 60% of the sand was washed away."
In Louisiana, the Army Corps has several ideas for reclaiming wetlands endangered by the encroaching sea. Among them: a series of major diversion schemes that will pipe fresh water from the Mississippi and spread it over marshland areas. By early 1988, the corps hopes to launch the first large project, a $25 million culvert system that will fan fresh river water out on the marshes near Breton Sound, which have been overrun and heavily damaged by saltwater intrusion. Says Cletis Wagahoff, chief of the corps's planning division for the New Orleans district: "It's not the ultimate answer -- I don't foresee one -- but I'm confident we can slow erosion down." A program already under way has created 3,000 acres of new marshland with sediment dredged up in the process of maintaining waterways.