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Sequoia Ecological Consulting, Inc. CalVTP Project-Specific Analysis and Addendum Augustin Bernal Community Park Fuel Reduction November 2025 4-50 4.6.1. Discussion The project area is located in Alameda County, within the Coast Ranges Geomorphic Province, which is characterized by northwest-trending mountain ranges and valleys (California Geological Survey [CGS] 2002). The Coast Ranges are primarily composed of Jurassic- to Cretaceous-age (about 65–150 million years old) marine sedimentary and volcanic rocks of the Franciscan assemblage. The Franciscan assemblage consists of partially metamorphosed greenstone, basalt, chert, and graywacke that originated as sea floor sediments. The California Department of Conservation CGS Landslide Inventory (beta) map (CGS 2015) and the CGS Earthquake Zones of Required Investigation Dublin Quadrangle (CGS 2008) were reviewed to identify unstable areas within or in proximity to the treatment areas. The treatment areas are located on and surrounded by land that has been and currently is subject to landslide, both weather-induced and seismically induced. Soils within the treatment areas are dominated by Los Gatos–Los Osos complex, 30 to 75 percent slopes, eroded (65.3 percent), and Millsholm silt loam, 30 to 45 percent slopes (20.0 percent). Other soils make up smaller percentages of the project footprint, such as Los Osos and Millsholm soils, 7 to 30 percent slopes (8.1 percent), and Millsholm silt loam, 45 to 75 percent slopes, eroded (6.5 percent; Natural Resources Conservation Service [NRCS] 2025). Table 8 below shows all soil types present within the footprint of the treatment areas. The parent material for these soils consists of sandstone and shale, and these soils are well drained to somewhat excessively well drained (NRCS 2025). The erosion hazard for the soils ranges from moderately low to moderately high (NRCS 2025). As stated in the project description, mechanical treatments would occur but would occur predominantly on slopes below 40 percent grade, along ridges, and on slopes greater than 40 percent grade with equipment that can reach target vegetation from existing road infrastructure. No mechanical treatment would occur on slopes greater than 50 percent. Table 7. Soil types and percentages within the project area. Soil Type Acres Percent of Total Footprint Los Gatos-Los Osos complex, 30 to 75 percent slopes, eroded, Major Land Resource Area 15 105.8 65.3% Los Osos and Millsholm soils, 7 to 30 percent slopes 13.2 8.1% Millsholm silt loam, 30 to 45 percent slopes, eroded 32.3 20% Millsholm silt loam, 45 to 75 percent slopes, eroded 32.3 20% Totals 161.9 100.0% Source: NRCS 2025.