PC-92-16 - Laserfiche WebLink

50. Prior to submittal of a tentative map, the applicant shall prepare detailed geotechnical studies to determine the final landslide repair measures necessary to assure development of the project as approved. If the landslide repair measures extend beyond those anticipated in the geotechnical studies prepared to date (July 30, 1991) and as shown on the landslide buttress plan (Figure 9-3, Chapter 9 of the SEIR), the Planning Commission may elect to require elimination of those lots whose creation would require landslide repair measures which the Planning commission determines would have adverse impacts visual, grading, drainage and vegetative etc., on the environment. The Planning commission may make this decision when it considers the tentative map approval for this project. 51. A comprehensive and thorough slope stability investigation is required. Prior to the Tentative Map approval and issuance of a grading permit for the SUbdivision, all landslides and areas with a high potential for slope instability should be identified, mapped and categorized as to their potential effect on the development. The project's geotechnical engineer and/or certified engineering geologist should provide recommendations for stabilization of the areas identified. The identified areas should include all landslides and potential landslides on-site and all landslides off-site that may impact on-site development, as well as landslides on-site that may affect adjacent properties. This work should include preparation of a detailed geologic map and performance of a subsurface investigation within each area with a high potential for future slope movement. A thorough slope stability analysis should include considerations of the maximum seismic accelerations which might be transmitted, especially in regard to saturated soil conditions. The project engineer and engineering geologist also should provide recommendations for location of a suitable building envelope for each hillside lot. Additional recommendations should be made as to the hazard feasibility of developing lots heavily-impacted by landslides, landslide repair, or potential slope failure. (MM 9.A.l) 52. A detailed construction plan should be prepared by the project's geotechnical engineer and/or certified engineering geologist for the stabilization of all on-site landslides and potential landslides, all off-site slides that may affect the project or adjacent off-site developed areas. The depth and lateral dimensions of each landslide should include detailed section and plans showing the limit of work along with detailed grading specifications for performance of the stabilization work. All landslides and potential landslides which could affect the proposed project should be stabilized by the developer before individual lots are sold. (MM 9.A.2)