LOS ANGELES (CBSLA.com) — Last year’s El Niño didn’t bring pounding rain to Southern California, but it did deliver strong waves that battered beaches.
Now, researchers say those strong swells contributed to an unprecedented level of beach erosion along the West Coast.
Erosion along West Coast beaches last winter was 76 percent higher than normal, according to a study published last week in the journal Nature Communications.
“Wave conditions and coastal response were unprecedented for many locations during the winter of 2015-16,” Patrick Barnard, lead author of the paper and a geologist with the U.S. Geological Survey, said in a statement.
Erosion is normal during winter months, when strong waves typically carry sand away from beaches. But last winter’s strong swells swept away far more sand than is normal, according to the researchers, who studied dozens of beaches from Washington to Southern California.
Ordinarily, sand is restored to beaches during the summer, when gentler seas have a less corrosive effect. Rivers also play a crucial role in replenishing beaches by depositing sediment at river mouths.
But researchers say the lack of rainfall last year meant less sediment flowed to beaches from rivers.
“The lack of rainfall means that coastal rivers produced very little sand to fill in what was lost from the beaches, so recovery has been slow,” David Hubbard, a co-author of the paper, said in a statement.
This year’s deluge of rain would appear to help, but scientists say sediment in Southern California often doesn’t make it to river mouths. Instead, it is often trapped upstream by man-made dams.
Robert Steward, a Malibu beach-goer, said he sees erosion continuing this winter as a series of strong storms has delivered high surf to area beaches.
“When you look down the beach towards Point Dume you can see the big insert where the waves have come and eroded the beach away,” he said
Surfer Christian Bridley says he thinks the sand will eventually be replenished — “maybe a little slower this time, but it’ll come back,” he said.