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Coastal cities prepare for rising sea levels

Newport Beach and other communities on California's coast are planning to build up wetlands, construct levees and seawalls or move structures inland as climate change raises sea levels.

March 06, 2011|By Tony Barboza, Los Angeles Times
  • Water surges over the seawall on Balboa Island in December, when a major storm hit during an extremely high tide. Newport Beach city workers had to pump the water back into the harbor.
Water surges over the seawall on Balboa Island in December, when a major… (Newport Beach General Services )

Cities along California's coastline that for years have dismissed reports of climate change or lagged in preparing for rising sea levels are now making plans to fortify their beaches, harbors and waterfronts.

Communities up and down the coast have begun drafting plans to build up wetlands as buffers against rising tides, to construct levees and seawalls to keep the waters at bay or to retreat from the shoreline by moving structures inland.

Among them is Newport Beach, a politically conservative city where a council member once professed to not believe in global warming. Now, the wealthy beach city is considered to be on the forefront of preparing for climate change.

Though some in Newport Beach remain skeptical that global warming caused by humans is elevating sea levels, city planners are looking at raising seawalls by a foot or more to hold back the ocean. New homes along the city's harbor are being built on foundations several feet higher than their predecessors as a precaution against flooding.

"I feel a real sense of urgency to begin planning for this right now," Mayor Michael Henn said. "To me it's irrelevant what the causes of global warming are. What we are dealing with is the reality that sea levels are rising."

Sea levels have risen about 8 inches in the last century, and scientists expect them to rise several feet by the end of this century as climate change warms the ocean.

The focus on adaptation is a marked shift for cities such as Newport Beach that just a few years ago had made few preparations for the effects of climate change or were focusing on reducing their carbon footprints. Even as the California Legislature passed a landmark law in 2006 to reduce greenhouse gas emissions, few coastal cities had any plans to confront rising waters on their own shores.

"The state of preparedness was close to zero in terms of looking forward to climate change and what it's going to bring," said Susanne Moser, a social science researcher at the Woods Institute for the Environment at Stanford University, who has surveyed coastal cities and counties about planning for rising sea levels. "Since then there's been an explosion of interest on the local level."

In Newport Beach, the attitude change came in response to concerns about the future of its harbor, an expansive waterfront dotted with islands and sheltered from the open ocean by the densely populated Balboa Peninsula. Tens of thousands of people live in the area, much of it just a few feet above sea level.

After a sea level rise of just over a foot, a 2008 city-commissioned study said, an extreme high tide would result in widespread flooding on Balboa Peninsula and "near-complete flooding of Balboa Island."

With that in mind, Newport Beach officials are focusing on low-lying Balboa Island, a tightly packed neighborhood of homes and beach cottages where locals zoom through the streets on golf carts and navigate the harbor in electric boats. A narrow sand spit that was dredged into an island a century ago, Balboa Island now houses nearly 2,000 homes, which are considered to be at the greatest risk of flooding in the city.

To protect against that possibility, new homes are already being built on foundations about three feet higher than the historic beach cottages they replace. And the city is conducting a study of the island's seawalls, built in the 1920s and '30s, to determine how high they will have to be raised.

Longtime residents point to eroding beaches and an increase in the number of unusually high tides over the years as evidence of a worsening problem.

In December, when a major storm hit during an extremely high tide, waves broke over the seawall and water pooled on sidewalks and streets. There was no serious damage to homes, but city workers had to pump the water back into the harbor.

Still, many islanders don't believe in human-induced climate change and remain unconvinced that an encroaching sea is a pressing problem.

Seymour Beek, whose family operates the ferry that connects the island to Balboa Peninsula and lives in an island home his parents built in 1922, said the threat has been overblown.

"The projections," he said, "I don't trust any of them. There's going to be plenty of time to cope if there is a significant amount of sea level rise."

Others think the risk is more imminent.

John Corrough, a coastal planner and former city harbor commissioner who lives on the island's south bayfront, said he would welcome the city raising the island's defenses.

"We now have four generations that have lived a good chunk of their life on this piece of sand and their cousins and grandpas and uncles lived on the next piece of sand over," he said. "We're counting on being able to continue this tradition into the future."

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