SOLANA BEACH, Calif. (AP) -- Atop the ocean bluff are the homes of those fortunate to own a piece of land overlooking the dramatic California coastline. Down on the beach are the surfers, swimmers and beachcombers lucky for a sliver of sand that skirts caves and coves in this paradise north of San Diego.
Dividing the two is a crumbling 80-foot cliff that forms a battle line between homeowners who built concrete walls to prevent their houses from sliding into the sea and those who want to put limits on how long they can fend off the waters.
The powerful California Coastal Commission is imposing 20-year caps on permits to build sea walls, setting up a classic debate over public beach access and property rights as sea levels continue to rise and relentless surf threatens to erode a way of life along 1,100 miles of shore.
Since 2010, the agency has set 20-year expiration dates on a private tennis club in Pebble Beach, a 13-unit apartment building in San Diego, two houses in Santa Cruz, a 19-unit apartment building in nearby Capitola, a 260-unit apartment complex in the San Francisco-area town of Pacifica and several homes in Solana Beach and neighboring Encinitas.
While the limits aren't edicts to tear down walls in two decades and wouldn't necessarily prevent shoring up fortifications later, they have alarmed homeowners who see a threat to their property.
"There's going to be a huge dark cloud whether the home can still exist when the period is over," said Jon Corn, an attorney for homeowners who sued Solana Beach after the city adopted a similar 20-year limit for all new walls on its 1.7 miles of coast.
Three lawsuits are pending in state court to overturn the city's policy.
Solana Beach could become a model for 75 other cities or counties required to run plans by the Coastal Commission. Environmental groups who fear that beaches could disappear under rising seas fueled by global warming if huge swaths of coast are allowed to be armored forever hope California sets an example for coastal states such as North Carolina and Florida.
"We're going to need to step back," said Mark Rauscher, Surfrider Foundation's coastal preservation manager. "We can't beat the ocean forever."
The commission is years from deciding what to do when the first permit expires. It will depend on how sea levels or other conditions play out.
"It's simply saying you'll be re-evaluated in 20 years," said Diana Lilly, an analyst at the commission's San Diego office.
Courts are likely to weigh in beforehand.
In one skirmish this year, a judge struck down a 20-year limit on two nearby Encinitas homes, saying the cap was arbitrary. As a Superior Court ruling, it does not set a precedent for other cases.
There is no precise tally of seawalls in California or nationwide, but they are common in Malibu, San Francisco and other places. They tower over the shores of Solana Beach, a suburb of 13,000 people that has long been one of the San Diego region's most coveted places to live. Houses and condominiums crowd the oceanfront, with one 1,300-square-foot home listed at $2.4 million.
Solana Beach is cursed by a layer of sand about 30 feet from the ground that, when exposed, makes homes highly vulnerable to sinking. The city's main beach, Fletcher's Cove, opened in 1924 when workers sprayed a hose to loosen bluff and shoveled dirt to make room. Five people have been killed by falling bluffs at nearby beaches since 1995, most recently a tourist who died in 2008 at Torrey Pines State Beach.
Tom DiNoto considers himself lucky for having built his wall about four years ago without an expiration date, though he worries limits on new construction will hurt home values. He paid about $500,000 for a 40-foot-high concrete wall that stretches along 50 feet of shore and is colored and sculpted to blend with natural surroundings. About $250,000 more went for engineering and other fees, including the cost for bringing in sand to fortify beaches.
Last year, San Diego's regional planning agency pumped 1.5 million cubic yards of offshore sand to Fletcher's Cove and seven other area beaches. Surfrider objected to an Army Corps of Engineers plan to dump even more sand in Solana Beach and Encinitas as detrimental to surfing conditions, but DiNoto echoes other homeowners who say it is a sensible way to protect homes without sacrificing beach.
"It's the public's beach but that doesn't mean we should be penalized," he said.
Signs below warn of unstable cliffs and lifeguards tell people to keep a distance.
On a recent Sunday, visitors saw the debate both ways.
Aaron Bert of Encinitas said the walls blight the landscape but that homeowners were entitled to protect their property.
Erik Marquez, who often takes his children to the beach from suburban Los Angeles, agreed.
"It's not like they're big developers bringing in their cranes," he said.
But Marquez said he would lose sympathy for homeowners if it meant surrendering public beach.