California’s coastal bluffs, cliffs, and iconic beaches face a perilous future, as rising seas and hammering waves, fueled by climate change, are causing increased rates of shoreline erosion.

Many beaches have been impacted by shoreline “protection” structures such as sea walls, revetments and rip-rap (boulders) that were installed in hopes of protecting coastal development. Ironically, these structures actually accelerate the rate of shoreline erosion. Waves that hit seawalls and other unyielding structures are reflected back towards the ocean or onto adjacent unprotected bluffs. Each reflected wave takes beach sand with it. Over time, the beach disappears. Usually, the most cost-effective long-term solution is to proactively retreat and let beaches naturally move inland as the sea rises.

Unfortunately, coastal property owners often lobby for more walls and barriers, making it difficult for local governments to orchestrate a managed retreat from the coast.

The California Coastal Commission, which is mandated by the Coastal Act to ensure maximum public access to our beaches, recently adopted new guiding principles to advance sea level rise adaptation planning and avoid loss of public beaches.

Some coastal cities and counties, which share coastal planning responsibility under the Coastal Act, have successfully addressed coastal erosion and sea level rise; others are lagging behind.

Half Moon Bay’s 2021 Local Coastal Program (LCP) Update includes stellar forward-thinking coastal hazard solutions in its new sea level rise adaptation policies. San Mateo County still needs to update its 1981 LCP hazard policies and is struggling to address shoreline retreat/inundation in low-lying areas such as Princeton. Pacifica’s efforts to adopt new LCP hazard policies ran into a buzz-saw of opposition, ultimately resulting in a change in City Council members; its LCP Update is now in limbo.

Green Foothills in 2019 appealed a permit in Moss Beach for development that we felt was too close to rapidly eroding bluffs. The Coastal Commission agreed, and required greater bluff setbacks, prohibition of future armoring of bluffs, removal of the structure if unsafe to occupy, and disclosure of coastal hazard risks to future buyers of the property.

We remain concerned about shoreline “protection” structures that were installed before the Coastal Act. These are considered “grandfathered” and therefore can be repaired or replaced, despite tremendous loss of beaches. For example, the bluffs at Surfer’s Beach south of the breakwater at Pillar Point Harbor are eroding seven times faster than before the breakwater’s construction in the early 1960s. Winter storms and high tides now threaten Highway 1 and the Coastal Trail. The San Mateo County Harbor District is initiating a short-term solution by moving tons of sand that have accumulated inside the breakwater to replenish the eroded beach. But sand replenishment is only a short-term solution, and the highway and trail will eventually need to be re-routed inland, as it’s unlikely that the root problem – the breakwater – will be removed.

We will continue working to ensure that new development on the San Mateo coast is located out of harm’s way, so that our beaches may remain treasured assets for all to enjoy.

For more info about the challenges to sea level rise along the coast, we recommend California Against the Sea, Vision for our Vanishing Coastline, by Roxanna Xia, Los Angeles Times coastal reporter; Heyday Press, 2023.