Seal Cove Landslide Surficial Surveying and Monitoring Services

The County of San Mateo (County) is seeking proposals from qualified engineering, geological, and land surveying firms to establish and maintain a long-term surficial monitoring program for the Seal Cove landslide complex and Bluff Retreat. This project aims to expand upon existing monitoring efforts currently centered around the Moss Beach Distillery to provide a comprehensive understanding of ground deformation across the broader residential neighborhood within the landslide complex.

The Seal Cove neighborhood, located in the unincorporated Moss Beach area, is subject to three primary geologic hazards including active faulting, rapid erosion of coastal bluffs, and most notably deep-seated landslide movement across a large portion of the neighborhood. These hazards are documented in the “Seal Cove Geologic Study” commissioned by the County and published on December 15, 2025 in response to increased land movement observed in early Spring 2025. The Study concluded that the active deep-seated landslide complex had both expanded landward in the southerly portion of the complex and had increased rate of displacement in recent years. This rate of displacement, however, has only been historically measured in the northerly portion of the landslide complex, meaning that we have no data on displacement monitoring in the southerly portion of the slide. A map of the slide and neighborhood can be found in the “Seal Cove Geologic Study” which is publicly available on the County of San Mateo website. This project aims to expand upon the County’s existing monitoring network at the Moss Beach Distillery to provide a comprehensive understanding of ground deformation across the entire landslide complexes residential roadways and coastal bluffs to inform public safety and infrastructure planning.