Reso PC17-07 0032 PC Reso Approving CEQA - 860 Charter St

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LSA ASSOCIATES, INC. SEPTEMBER 2016 ROCKETSHIP REDWOOD CITY ELEMENTARY SCHOOL PROJECT INITIAL STUDY/ MITIGATED NEGATIVE DECLARATION P:\RWC1401B Rocketship School\PRODUCTS\IS-MND\Public\Rocketship Public Review 09-29-16.docx (09/29/16) PUBLIC REVIEW DRAFT 41 depressurization system (SSDS) designed to address the presence of VOCs inside the project site structure; no geologic impacts related to construction or operation of the SSDS were identified. a) Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving: i) Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault; ii) Strong seismic groundshaking; iii) Seismic-related ground failure, including liquefaction; iv) Landslides? (Potentially Significant Unless Mitigation Incorporated) Fault Rupture. Fault rupture is generally expected to occur along active fault traces that have exhibited signs of recent geological movement (i.e., within the past 11,000 years). Alquist-Priolo Earthquake Fault Zones delineate areas around active faults with potential surface fault rupture hazards that would require specific geological investigations prior to approval of certain kinds of development within the delineated area. The project site is not located within or adjacent to an Alquist-Priolo Earthquake Fault Zone.28,29 The Alquist-Priolo Earthquake Fault Zone for the Cañada Fault (a local splay of the San Andreas Fault) is located approximately 4 miles southwest of the project site and the Alquist-Priolo Earthquake Fault Zone for the San Andreas Fault is located approximately 4.5 miles southwest of the project site. Additionally, the project site is not located over any other potentially active faults (faults that have shown evidence of movement in the past 2 million years) that cross Redwood City.30 Therefore, the potential of the proposed project to expose people or structures to risk as a result of fault rupture is less than significant. Ground Shaking. There are multiple active faults that have the potential to generate strong to violent ground shaking at the project site.31 These faults include the San Andreas Fault, located about 5 miles to the southwest; the San Gregorio Fault, located about 14 miles to the southwest; the Hayward Fault, located about 14 miles to the northeast; and the Calaveras Fault, located about 20 miles to the northeast.32,33 The U.S. Geological Survey’s Working Group on California Earthquake Probabilities estimated that there is a 63 percent probability that one or more moment magnitude (Mw) 6.734 or greater earthquakes will occur in the San Francisco Bay Area between 2007 and 2036. The probability of a MW 6.7 magnitude or greater earthquake occurring along individual faults was estimated to be 21 percent along the San Andreas Fault, 31 percent along the Hayward Fault, and 7 28 California Department of Conservation, 1982. Alquist-Priolo Special Studies Zones, Palo Alto Quadrangle. Website: www.quake.ca.gov/gmaps/WH/regulatorymaps.htm. 29 Redwood City, City of, 2010. Redwood City General Plan - Public Safety Element, Figure PS-2. 30 Ibid. 31 Association of Bay Area Governments, 2014. Geographic Information Systems, Shaking Scenarios. Website: gis.abag.ca.gov (accessed November 14, 2014). 32 California Geological Survey, 2010. 2010 Fault Activity Map of California, Geologic Data Map No. 6. Website: www.quake.ca.gov/gmaps/FAM/faultactivitymap.html (accessed November 14, 2014). 33 Association of Bay Area Governments, 2014, op. cit. 34 Moment magnitude (MW) is now commonly used to characterize seismic events as opposed to Richter Magnitude. Moment magnitude is determined from the physical size (area) of the rupture of the fault plane, the amount of horizontal and/or vertical displacement along the fault plane, and the resistance to rupture of the rock type along the fault. ATTY/RESO.0032/PC RESO APPROVING CEQA - 860 CHARTER ST. EXHIBIT A REV: 06-15-17 PR Page 49 of 124