Portuguese Bend Landslide Remediation Project

Portuguese Bend Landslide Remediation Project

The Portuguese Bend Landslide began moving in 1956, and continued land movement has resulted in significant damage to homes, infrastructure, utilities, roadways, and impacts to native vegetation and project area drainage courses. The proposed project is intended to significantly minimize movement in the existing landslide area by implementing a series of recommended geotechnical engineering solutions that will include relief of artesian pressure below the landslide basal surface and minimize stormwater infiltration into the subsurface. Thus, the proposed improvements include infilling surface fractures to reduce infiltration of surface water into the ground; constructing surface drainage swales and retention areas to collect, slow, and convey surface water to the ocean; and installing a subsurface water extraction system (hydraugers) by means of directional drilling to alleviate artesian pressure and also lower groundwater levels within the landslide mass. The proposed project would construct the improvements depending on factors such as funding. The construction may occur separately by component or concurrently. After construction, inspection of each of the project components would be conducted on a regular basis, and maintenance activities would be conducted on an as-needed basis. Project implementation would not result in any significant and unavoidable environmental impacts.

Rancho Palos Verdes

Los Angeles

Southern California

California Air Resources Board (ARB), California Coastal Commission (CCC), California Department of Conservation (DOC), California Department of Fish and Wildlife, Marin Region 7 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of State Parks, Division of Boating and Waterways, California Department of Toxic Substances Control (DTSC), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Los Angeles Region 4 (RWQCB), California Santa Monica Mountains Conservancy (SMMC), California State Lands Commission (SLC), Office of Historic Preservation, Santa Monica Bay Restoration, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Division of Water Rights, State Water Resources Control Board, Divison of Financial Assistance, California Department of Transportation, District 7 (DOT), California Department of Fish and Wildlife, South Coast Region 5 (CDFW)

California Department of Transportation, District 7 (DOT), California Department of Fish and Wildlife, South Coast Region 5 (CDFW)

Other (Landslide control)

Coastal Permit, Grading Permit/Site Plan Review

Aesthetics, Air Quality, Biological Resources, Coastal Zone, Cultural Resources, Cumulative Effects, Drainage/Absorption, Energy, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Noise, Recreation, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire