11B Public Hearings - Laserfiche WebLink

Home

SAN LEANDRO SHORELINE DEVELOPMENT EIR ADDENDUM PROJECT CITY OF SAN LEANDRO May 2022 Page 31 Comments: GEO-a, i, ii, iii, iv. The location and precise boundary of the Modified Project are the same as those of the Approved Project. Since the project site remains outside of any Alquist-Priolo Fault Zones, the risk of surface rupture during an earthquake remains low. The same applies to landslide risk: the Modified Project does not increase landslide risk any more than the Approved Project since the boundaries and location of the site have not changed. Because the site topography is generally flat, there is little to no erosion or landslide hazard. As stated in the Geology and Soils chapter of the Certified EIR, the Project site lies along the eastern margin of San Francisco Bay on the low-lying coastal plain and adjacent filled portions of the bay. While the site is not near enough to any fault lines to be considered at risk of surface rupture according to the Alquist-Priolo fault zone map, it is still proximate to several earthquake faults to the east and west. The Original Project EIR also notes that the western half of the project site, roughly delineated by Monarch Bay Drive, is comprised of filled-in Bay Mud (approximately ten feet thick) over alluvial deposits of sand, silt and clay. The eastern portion of the site, demarcated by where the original coastline began roughly along Monarch Bay Drive, is comprised of the same alluvial deposits but without the additional layer of filled Bay Mud. The relatively thick alluvial deposits on both the eastern and western portions of the project Site could cause amplified ground shaking and liquefaction during an earthquake. The fill over Bay Mud in the western portion of the project Site further increases the risk of severe shaking and liquefaction. The Modified Project adds an additional 6 housing units over the Approved Project, with an associated increase of approximately 16 new residents under the assumption of 2.74 residents per housing unit.10 While these modifications would increase the number of people and structures on soil with a risk of severe shaking or liquefaction, all development on the Project site would necessarily comply with California Building Codes as well as San Leandro permitting codes, which both require additional structural engineering measures for developments on Bay Mud or other loose soils. Other modifications included in the project would not result in any new impacts or a significant increase in existing impacts. The previous determination for the Original Project of significant impacts before mitigation is still valid for the Modified Project, and therefore, the Modified Project would not result in a new impact or in a substantial increase in magnitude of existing impacts with regard to the risk of loss, injury, or death from any of the four geological hazards (i-iv) outlined in the table GEO-b, c, d, e, f. The location and precise boundary of the Modified Project are the same as those of the Approved Project. Construction under the Modified Project would not result in an increase soil erosion or loss of topsoil any more than the Approved Project since the boundaries and location of the Project site are unchanged. Thus, the Modified Project does not result in any new impacts or a significant increase in existing impacts in terms of soil erosion or loss of topsoil. 10 City of San Leandro. 2015. Housing Element, 2015 – 2023. Available online at https://www.sanleandro.org/civicax/filebank/blobdload.aspx?BlobID=23216, accessed January 6th, 2020.