How To Wreck a Beach

It’s easy to destroy the natural processes of beach formation with enough large rocks and money. That’s what the U.S.Army Corps of Engineers did in 1959 when they built the long planned Pillar Point Harbor breakwater. Before the breakwater, waves from the northwest bent around the point and lost much of their energy, and waves from the south broke on the broad sandy beach south of the point, seldom affecting erosion of the bluffs. Fishing boats, however, were subject to the powerful waves and were regularly dragged off anchor and wrecked on the beach. Locals started asking the federal government for a breakwater as early as 1911.

After the breakwater was built, waves deflected off the breakwater and were forced to smash onto El Granada and Miramar Beaches. Within ten years the beaches were virtually gone. Without the sand as a buffer, the waves quickly eroded an astounding 150 feet of bluff along the length of the beach. It’s still receding about five feet a year. Instead of a broad beach serving as a natural barrier to the ocean’s power, only a steep, narrow bluff armored with rock remains. In the early 20th century EI Granada Beach was touted as “The Coney Island of the West, the most remarkable stretch of clean, sandy, safe beach in the world.” Now the narrow beach is walkable only at low tide.

Any attempt to armor the shoreline will likely fail. Coastside residents had used the old Mirada Road since the 1850s. After the breakwater was built, the San Mateo County government tried to save the road from the invading ocean by armoring it with riprap, but the effort failed. Now at low tide you can see the riprap in the surf 150 feet from the bluff and historic Mirada Road is entirely gone.

Thanks for help from The Coastside Trail Guidebook by Barbara VanderWerf.

Update: The southern section of Mirada Road has been converted to California Coastal Trail that now connects to the 7.5 mile long Half Moon Bay Coastal Trail with a new pedestrian and bicycle bridge reinstalled in October of 2023. Erosion along the trail as well as loss of beach continues to be an issue.