Warding off waves with walls

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.

David Oakley of Encinitas joined 12 neighbors and built a 740-foot sea wall after storms battered the coastal bluff supporting his house five years ago. Far from wanting to slow sea-wall construction, he thinks it should made be easier to build them.

"Without that wall, the bluff would have collapsed and my house would have been sticking out and hanging over the bluff. Are we going to let houses just collapse and fall onto the beach?" Oakley says. "We should have the right to fix these bluffs so they don't collapse and kill people."

'Arrogant decision'


Others note that most of the coastal bluffs and beaches where sea walls are built are public property. "There's a small bunch of highly influential, wealthy and selfish individuals who made an arrogant decision to build right next to the ocean, and now they want to sacrifice beaches used by millions of people," says Orrin Pilkey, a coastal geologist and director of the Program for the Study of Developed Shorelines at Duke University. "Our policies should be to preserve the coast for the next generation and not choose buildings over beaches."

But the rich are not the only force promoting the spread of sea walls. Dams in the mountains choke off sediment that rivers and streams once carried to beaches. So do rail lines, highways, culverts and roads. As nature, with considerable help from human changes across the landscape, delivers less sand, sea walls have grown in appeal as the best defense along the beaches.

"This is not a natural shoreline anymore," says David Skelly, owner of a San Diego County coastal engineering firm. "It took us 200 years to develop our shoreline. We cannot change that overnight. Sea walls have a bad reputation, but they are an important tool."

But they are expensive to install. A homeowner can spend $150,000 for a sea wall. A mile-long wall can cost $15 million. Repairs cost nearly as much as the walls or revetments themselves. And taxpayers often pay for them through government disaster aid and local public works programs

In the end, relentless waves undercut sea walls or outflank them and attack their vulnerable backsides. Says Inman: "It may take 10 years or 30 or 50, but eventually they all fail. They have to, and they do."