OREGON STATE UNIVERSITY

El Nino's threat to Pacific beaches to linger

02/24/1998

CORVALLIS - West Coast beaches are losing thousands of yards of shoreline and the erosion may continue for at least two more years before the influence of one of the most powerful El Ninos of this century wanes, said Oregon State University researcher Paul Komar.

"We don't have the data to say for certain that this El Nino surpasses the El Nino of 1982-83," said Komar, an OSU professor of oceanic and atmospheric sciences. "But it certainly appears to be at least as powerful."

During the 1982-83 El Nino, homes pitched into the surf at Malibu Beach, Calif., and tons of sand washed away from coastal spits at Alsea and Netarts on the Oregon Coast, threatening homes and campgrounds.

Until the 1998 winter storm season ends, Komar cautions coastal residents to remain alert.

"If an area hasn't experienced any significant erosion by this time, it is probably safe, but I wouldn't rest completely for another month," he said.

Exposed spits and inlets to bays, as well as coastlines north of headlands are at the greatest risk, Komar said.

El Ninos hasten erosion along the Pacific Coast by pushing water from the southern hemisphere northward, said Komar, who has written several books on erosion and serves as editor of the journal Shore and Beach, which focuses on the science and management of coastal erosion.

Water levels can rise up to about two feet beyond expected tidal levels during El Nino years. While the increase in water level isn't serious by itself, when the right combination of storm waves, high tides and increased water comes together it can cause severe erosion, he said.

Already, El Nino has caused serious damage along the Oregon Coast. In Oceanside, homes at The Capes development are on the brink of tumbling into the sea. And, at Port Orford, high water has destroyed part of the town's sewage treatment plant and threatens the region's water supply.

Komar and William McDougal, OSU professor of civil, construction and environmental engineering, have analyzed the problem at Port Orford and are recommending the town use cobblestones or large sandbags to keep the surf out of the municipal sewer and waterworks.

McDougal is an expert on coastal protection and ocean engineering.

"This is the first time in the historical record that this type of erosion has occurred in the Port Orford area," Komar said, although scientists believe a large tsunami in the 1700s may have caused similar damage.

The main thrust of El Nino should wane by May, but it will be several years before everything returns to normal, Komar said.

While much of the focus has been on El Nino's negative effects, the phenomenon does has a positive side, Komar said.

"In some areas there is simply too much sand." For example, sand dunes on Kiwanda Beach continually threaten to engulf homes.

"El Nino should help take care of that problem for a while," Komar said.