Warding off waves with walls


Sea walls: The surf keeps pounding coasts, but efforts to stop the inevitable raise concerns that the attempts at prevention are worse than the damage.

June 03, 2000|By Gary Polakovic | Gary Polakovic,LOS ANGELES TIMES

In the Southern California beach city of Encinitas, two big houses that neighbors Stanley Cantor and Paul Denver built on a coastal cliff north of San Diego were in danger of toppling into the Pacific 80 feet below, so they built a sea wall to check erosion.

Near Pismo Beach, along the Central California coast, waves gnawing at a bluff posed a hazard to the Cliffs hotel, so the owner installed a 13-foot-high boulder facing on the beach.

And in Northern California's upscale town of Carmel, big winter storms three years ago obliterated much of the slope beneath Carl and Jane Panattoni's house, so they are building a 260-foot wooden barricade to hold back the waves.

So it goes, up and down the coast of California, in a pattern as predictable as the tides: People move to the rim of the Pacific, the ocean attacks, and bulwarks are thrown up to keep buildings from sliding into the surf.

About one-quarter of the shoreline along a 535-mile stretch from the Golden Gate Bridge to the Mexican border is now fortified, according to the California Coastal Commission. And the pace of construction is accelerating. The agency estimates that about 10 miles of sea walls were added in the past decade.

"Sea walls are the single worst coastal crisis in California," says Mark Massara, coastal program manager for the Sierra Club. "We are slowly but surely walling off the entire coast."

And other coasts as well. About half of the Florida peninsula and of the New Jersey coast are walled. Sea walls cover all of the developed coast of Georgia and about one-quarter of North Carolina's.

Sea walls are more than an aesthetic issue. The structures can destroy beaches and block coastal access. They cost a bundle to build and maintain, but inevitably succumb to the constant pounding of breakers. And they frequently benefit only a few wealthy residents at the expense of other beachgoers.

Surrendering homes

Some states - including Oregon, North Carolina, Maine, Rhode Island, South Carolina and Texas - have banned new sea walls. Others have imposed significant restrictions and are opting for other strategies, such as hauling in sand from the desert.

Twenty coastal states have adopted setbacks to put more land between buildings and surf. Some states allow buildings to tumble into the sea; others relocate them before the ocean can claim them, in a strategy called "managed retreat." Its most visible beneficiary is the 128-year-old Cape Hatteras lighthouse, rescued from an eroding sand spit on North Carolina's Outer Banks last year. Movers spent $10 million to push the 4,800-ton structure more than half a mile inland from the encroaching Atlantic.

In Oceanside, Ore., dozens of luxury townhouses were less fortunate. Given the choice of protecting homes or the beach, Gov. John Kitzhaber in 1998 forbade construction of a revetment. Many of the dwellings are condemned.

In California, state law requires that a sea wall be approved if any structure is threatened. The alternative is to watch million-dollar homes break up in the surf like driftwood, and so far the state hasn't found the courage, or callousness, to do that.

About 80 percent of California's 33 million people live within 30 miles of the ocean. Demand has grown for more seaside recreation opportunities, including campgrounds, bike paths and golf courses.

The seaside, too, is home to a host of essential public structures, including military bases, sewage-treatment plants, power plants and railways. With this development has come a need for fortifications to defend all the septic tanks, parking lots and patio decks.

Thus, sea walls. They come in many forms, from granite boulders to gunite-coated cliffs, from rows of wooden pylons to three-story concrete walls.

Surfers, environmentalists and many scientists and engineers argue that beaches are public resources that sea walls damage. Boulder revetments, for example, bury vast tracts of sand. Sea walls also prevent beaches from retreating ahead of advancing waves, so they get engulfed as water claws inland.

Studies show that sea walls act as mirrors, reflecting wave energy and churning the water so severely that sand is often washed away, leaving behind scoured cobble.

"If we continue, we will have an armored coastline without beaches," says Douglas L. Inman, professor of oceanography and founding director of the Center for Coastal Studies at the Scripps Institution of Oceanography in La Jolla. "If you like beaches, you can't be a fan of armoring the coast."

Moreover, by displacing beaches, sea walls contribute to the elimination of nature's perfect shock absorber for angry seas: sand. With less of it to slow onrushing surf, coastal buildings and cliffs suffer heavier wave damage. And because sea walls lock up earth behind them, less material gets sloughed into the breakers and pulverized into new sand to replace lost beaches.

Yet for coastal property owners, the walls may be the only thing separating them from disaster.

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