SCH Number 2020110212

Project Info

Title

Portuguese Bend Landslide Remediation Project

Description

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.

2 documents in project