Some towns eye retreat from sea

Many costal areas attempt to curb coastal erosion.

example can be found in Alaska, where entire villages have been forced to move to higher ground.

Hawaii’s famous beaches are slowly shrinking and some scientists think it’s a matter of time before the state has to explore whether to move back development.

Several states along the Atlantic coast have adopted policies meant to keep a distance from the ocean. They include nobuild zones, setbacks or rolling easements that allow development but with a caveat.

Over the past halfcentury, the weapon of choice against a shrinking shoreline has been building a seawall or other defense.

Roughly 10 percent of California’s 1,100mile coast is armored. In Southern California, where development is sometimes built steps from the ocean, a third of the shore is dotted with man-made barriers.

While such buffers may protect the base of cliffs, and the land and property behind them, they often exacerbate the problem by scouring beaches, making them narrower or even causing them to disappear.

San Francisco is mulling a significant retreat on its western flank where the scenic Great Highway is under assault from the Pacific. Erosion has inched closer to the roadway each year, and the U.S. Army Corps of Engineers continues girding segments with brokenup rock, a costly temporary fix that has had limited success.