San Francisco Fights Erosion as Coastal Cities Watch Closely
The explosive waves of Ocean Beach, a 3.5-mile stretch separating the city from the gray edge of the Pacific Ocean, have long been a draw for tourists, local families and an international tribe of surfers.
But every few years, stormy surf driven by the weather pattern known as El Niño grinds away at a thinning section of beach, pulling sand out to sea. Some comes back, but two years ago, bluffs collapsed and massive amounts of sand disappeared for good.
Holding back the sea here seems as impossible as holding back the fog. But planners see Ocean Beach as a top priority in a long roster of Bay Area sites threatened by inundation because of what lies on its landward side: the Great Highway, a $220 million wastewater treatment plant and a 14-foot-wide underground pipe that keeps sewage-tainted storm water away from the ocean.
The question facing at least eight local, state and federal agencies boils down to this: With California officials expecting climate change to raise sea levels here by 14 inches by 2050, should herculean efforts be made to preserve the beach, the pipe and the plant, or should the community simply bow to nature?
“We are in some ways the tip of the spear for this issue,” said Benjamin Grant, a city planner who is leading a study of the problem for the nonprofit San Francisco Planning and Urban Research Association, or SPUR.
Mr. Grant describes the beach’s south end as “an erosion hot spot.” But, he said, all coastal communities will have to grapple with rising seas.
A disruptive rate of sea-level rise is one of the most daunting potential consequences of climate change. Recently, researchers warned in two new studies that severe coastal flooding could occur regularly in the United States by the middle of the century and that California would be among the states most affected. Previous studies have suggested that the rise in sea levels is poised to accelerate globally, although the evidence that this is happening is not yet definitive.
“Communities will be forced to respond in one way or another to the increased erosion and coastal storm damage,” economists at San Francisco State University concluded in a recent study. Communities can either plan for the long term or improvise, storm by storm, until ad hoc solutions are inadequate, they warned.
Officials in cities across the United States and Canada are staying in close touch with San Francisco planners. “People often wait to see what California does” about environmental hazards, said Gary B. Griggs, a professor of earth and planetary sciences at the University of California, Santa Cruz. “So we have a chance to have a big impact.”