SOLANA BEACH, Calif. - Staring up at his home here, Paul Santina sees dreams collapsing.

He and thousands of others who own beachfront castles atop sandstone bluffs in California are watching their foundations disappear, one grain of sand at a time. From a beach that is submerged at high tide, Mr. Santina points 80 feet up to his neighbor's patio, which has hung precariously since this summer, when the bluff below it collapsed.

"Over the last 18 to 24 months," Mr. Santina said, "it has accelerated from one or two bluff failures a year to one or two a month."

Mr. Santina, who leads a group called the Beach and Bluff Conservancy, sees salvation in sand replenishment, artificial reefs and especially seawalls, hills of rock or concrete that reinforce the bluffs.

Environmental groups say such measures favor property owners at the expense of the public good and advocate the opposite approach, a program of "planned retreat."

California has the least restrictive seawall regulations in the country, environmental groups say. For example, Texas, North Carolina and South Carolina prohibit seawalls. This year state legislation was introduced that would make the permit process for seawalls more stringent. Faced with fierce opposition from homeowners and builders' groups, it has since been shelved, but a new bill is being prepared for next year.

The seeds for the current beach erosion were sown by bulldozers from the 1960's to the 1980's, when prime beachfront real estate was rapidly and densely developed.

Dave Skelly, a coastal engineer, said beaches had been robbed of sand by California's 1,400 dams and reservoirs, 200 debris basins, sprawling housing tracts and miles of concrete stream diversions. Encroaching development has "narrowed the beaches to the point that there is no sand," he said.

A recent study found that more than 100 of California's 1,100 miles of coast were armored, or shored up, with seawalls or jetties - a 400 percent increase since 1970. Environmental groups argue that such measures improperly occupy public beaches, making them unusable.

"There is no vested right to build a seawall on public property," Jim Jaffee, director of California Beach Advocates, said.

The Surfrider Foundation, an environmental group that claims 35,000 members, says that by "fixing" the shoreline and preventing natural sand release from bluffs, seawalls contribute to erosion, creating the need for more seawalls.

Many seawalls exist because of an apparent contradiction in the state Coastal Act. Part of the act states that property may be developed only if a seawall is not required, but another part says that if an emergency can be proved, a seawall "shall" be allowed to protect a structure.

To address this loophole, Assemblywoman Patricia Wiggins, who represents Napa County in Northern California, sponsored a bill that changes "shall" to "may." This proposed change drew opposition from homeowners and builders, who say the shift would allow the commission to let homes fall into the sea. Surfrider and other environmental groups say planned retreat, and not armoring, is the best approach. In the short term, planned retreat includes temporary seawalls and sand replenishment to protect property. In the long term, the state government would buy out beachfront property at a discount while allowing homeowners to stay for 50 years. Then the houses would be demolished and the bluffs restored to a natural state.

Giving up an entire row of prime beachfront homes is simply untenable to Mayor Marcia Smerican of Solana Beach and many of her beachfront constituents. "You can't do it," Ms. Smerican said. "You go to the first row, the second and then what about infrastructure? Highway 101? Beach access? Restaurants?"

Surfrider says Ms. Smerican is ignoring an environmental impact report her office authorized. The report showed that erosion rates in Solana Beach equaled 27 to 40 feet every 100 years - not enough to pass the first row of homes.

Solana Beach residents hope to save their homes by creating a "hazard abatement district," financed largely by homeowners and a bond issue. The district would allow a long seawall designed to resemble the coastal bluffs, long-term sand replenishment and underwater "sand retention" devices or artificial reefs.

The coastal commission, California Beach Advocates and Surfrider Foundation are skeptical. "Sand retaining structures keep sand on one beach by robbing it from another," Christopher J. Evans, executive director of Surfrider, said.

Last year, as part of a $17.5 million project for San Diego County beaches, financed by the federal and state governments, Solana Beach had 200,000 cubic yards of sand pumped in. The project was considered a success in many communities, but little of this sand remains here.

"Property owners want private property rights, but we, the taxpayers, have to pay these subsidies so they can live on the front row," Mr. Evans said.

Mr. Santina countered that not building more seawalls would be disastrous for the community.

"Let houses fall into the ocean, let the community's economy be destroyed, ruin tourism and let kids get killed from falling bluffs," Mr. Santina said. "We want to rebuild the beaches."

http://www.nytimes.com/2002/10/27/national/27SEAW.html