Sunday, April 4, 2010

Southern California beach erosion is worst in a decade

Tony Barboza in the Los Angeles Times: …At Laguna's Rockpile Beach, the waves scrubbed the shore so heavily that jagged rocks and rusty remnants of an old sewer system that haven't been seen for years reemerged. "This year it was just plain rock pile," said Ken Frank, city manager of Laguna Beach. "Forget the beach."

And at Dockweiler Beach near Los Angeles International Airport, cobblestones are visible where there once was soft sand, and workers have been using heavy machinery to fill in some of the more perilous drop-offs.

….The storms' scouring of the Southern California shoreline -- remarkable at some beaches, barely noticeable at others -- has caused the worst damage and most significant beach erosion in at least a decade, according to parks and beach officials. In January and February, powerful swells, high tides and strong winds swept away tons of sand from the coastline, stealing as much as 30 to 40 feet of beachfront at some locations.

In the month or two since the El Niño-driven storms, coastal communities -- Laguna Beach, Malibu and Manhattan Beach among them -- have worked to patch the damage by making repairs and trucking in fresh sand, but some worry whether nature will return the sand as it has in the past.

The sand loss is a familiar phenomenon. Shifting sand is part of a natural cycle that happens each year. Each spring, potent storm surges pull sand from the beaches out to sea. Over the summer, gentler waves gradually push it back ashore.

Periodically, beach cities throughout Southern California try to make up for the so-called sand deficit by pumping the material in from offshore. Global warming and sea rise are contributing to the deterioration of beaches in the long term, scientists say, but those forces are not to blame for this spring's dramatic changes. It's the exceptional level of damage this year that has been cause for alarm….

Basketball courts at Venice Beach in Los Angeles, shot by Samoano, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License

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