A Solution for Surfers Beach in Sight?


By on Sat, November 14, 2009

Erosion of Surfers Beach west of El Granada, California, and sedimentation at the adjacent Pillar Point Harbor are both serious problems confronting the Coastside community. Representatives from many interested agencies, as well as members of the public, recently had an opportunity to share an understanding of the history of the area and consider possible approaches towards a solution to these problems.

You can watch the entire 3-hour meeting, including a very informative slide presentation, on MontaraFog at http://www.montarafog.com/Public-Policy/a-solution-for-surfers-beach-in-sight.html

Here’s a brief historical summary:

For millenia before human intervention, ocean waves interacted with relatively soft marine terrace deposits focused by rock outcroppings at Pillar Point and Miramontes Point, forming Half Moon Bay. The wave energy eroded the shoreline and ocean currents moved sediments to form a nearly-perfect log-spiral bay. The shoreline was in stable equilibrium, with typical erosion rates averaging a few inches per year.

In 1959 to 1961, the Army Corps of Engineers constructed the outer breakwater that protects Pillar Point Harbor. The natural ocean dynamics were upset. Wave energy—especially during storms—was refocused just south of the breakwater, on the area known locally as Mirada Surf. According to studies by Ken Lajoie of the U.S. Geological Survey, blufftop erosion rates increased dramatically, at some points reaching five feet per year. One consequence of the manmade wave patterns is the near-total loss of the bluffs at Surfers Beach (and significant loss of sand from the beach itself), as well as continuing loss of the San Mateo County park on Mirada Surf itself.

Meanwhile, littoral transport of sediments out of the part of the ocean that is now Pillar Point Harbor was blocked by the breakwater. The result is gradual filling of portions of the harbor, especially around the boat launch area. At low tide the amount of accumulated sediment is particularly dramatic.

What To Do?

The obvious solution, it would seem, is just to move the unwanted sand inside the harbor to the other side of the breakwater, where it is needed to replenish Surfers Beach and reduce erosion of the Mirada Surf area. But such a simple solution faces seemingly insurmountable obstacles. Of course, just as a starter, no government agency has any money these days to fix problems. But even if money were no object, no one wants to try a quick fix that only results in other environmental problems later.

Experts from the Coastal Sediment Management Workgroup presented some ideas. Surfers Beach is within the Gulf of the Farallones National Marine Sanctuary, as well as the Monterey Bay National Marine Sanctuary, and legislation prohibits disposal of spoils—i.e., the material that would be dredged from within the harbor—except at designated disposal sites. And Surfers Beach isn’t so designated. As one of the surfers noted, it would literally take an Act of Congress to allow an easy solution.

The group discussed possible approaches that might find support among all of the stakeholders, but as this was just an initial meeting to discuss the situation, nothing was decided.

The San Mateo County Harbor District convened this initial meeting of the Surfers Beach Shoreline Improvement Working Group for Pillar Point Harbor on Tuesday, November 10, 2009, at the Oceano Hotel, chaired by Peter Grenell, Harbor District General Manager. Attendees included representatives from the U.S. Army Corps of Engineers, Gulf of the Farallones National Marine Sanctuary, California Coastal Commission, Surfrider Foundation, Coastal Sediment Management Workgroup, United States Geological Survey, San Mateo County, and the San Mateo County Resource Conservation District. Brian Overfelt, Bob Battalio, and others spoke on behalf of the Coastside community.

Unfortunately, CalTrans and the City of Half Moon Bay were not represented. Erosion of Surfers Beach threatens the portion of the California Coastal Trail falling within Half Moon Bay city limits, and severe erosion threatens Highway 1. Portions of Mirada Road—the old Coast Highway decades ago—have completely fallen into the Pacific Ocean as a result of significant coastal retreat since the construction of the breakwater.

The Harbor District has not announced the date or location of a follow-up meeting.