Surfer's beach, Half Moon Bay, CA

Background of the Issue

In the early 1960s, the U.S. Army Corps of Engineers built the outer breakwater at Surfer’s Beach to create the harbor, which upset the natural ocean dynamics and exacerbated erosion rates by causing more sand to be deposited on the harbor side. Now only a thin strip of beach remains at Surfer’s Beach, limiting recreational uses of the beach, threatening habitat for the federally threatened western snowy plover, and eroding away the embankment of Highway 1.

Various agencies and individuals have offered up possibilities for the erosion problem. Those ideas include building an artificial reef, poking a hole in the breakwater to see if circulation could be restored, building a small structure to trap sand and haul it away, and dredging, although the impacts of these options have yet to be assessed.

Update – July 2011

The U.S. Army Corps of Engineers has decided to conduct a study that takes into account all the factors involved in the erosion at Surfer’s Beach in order to decide how to best solve the problem. To kick the $1.2 million study phase into gear, the engineers must establish the baseline condition of the eroding beach. To accomplish this, the engineers collaborated with the U.S. Geological Survey to disperse tide gauges and buoys to collect information about wind, waves and water. By studying the patterns of how sediment moves in waves, tides and currents, the engineers can begin to understand how to solve the problem.

“In understanding how the waves and tides and currents interact with each other, we’ll have a better understanding of the site, and we’ll better know how to reduce the erosion rates,” said the Army Corps Coastal Engineer Lisa Andes. “It’s really important to understand the site, before we start talking about solutions. The first step is defining the problem. And to do that we look at the tides and the waves and the current.”

The engineers will spend the summer analyzing data and calibrating a model of Surfer’s Beach, and then later this year will propose alternatives for the beach to the community.