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!1CIVIL ENGINEERS 18.C. - Page 280 I S SULARVNNEYERSORS P January 12, 2018 Site Assessment Studv Harbor View — Inner Harbor FLOOD ZONE The properties within the project site are located within Flood Zone X and Flood Zone AE, as defined by FEMA's Flood Insurance Rate Map (FIRM) 06081 C0302E for the City of Redwood City. The Zone AE represents the 100 -yr storm or the 1 % annual chance of flood, or the base flood, which has a 1 % chance of being equaled or exceeded in any given year. The Zone X represents the area outside the 500 -yr storm or the 0.2% annual chance of flood. The base flood elevation in Zone AE at the project site is shown as 10', referenced to the North American Vertical Datum of 1988 (NAVD88). SEA LEVEL RISE As indicated in the Inner Harbor Specific Plan and Harbor View Project Draft Environmental Impact Report (EIR) (ESA, 2015), in order to account for Sea Level Rise (SLR) an adaption strategy is proposed to address impending transformative change from sea level rise. One of the mitigation methods suggested within the EIR is using fill to raise the existing grade of the entire project area to an elevation that accommodates 3 feet of sea level rise added to the 100 - year base flood elevation of 10.7 feet NAVD88. For this site assessment it is assumed the elevation of the site is raised to the base flood elevation + 3 feet SLR + 1 foot factor of safety, to an elevation of 14.7 feet. This yields an approximate fill volume of 227,211 cubic yards (CY) needed to raise the entire site at a cost of $3,408,158 for fill import. This fill is assumed for both project scenarios, giving a price per SF of building of $2.89/SF and $4.13/SF for the Proposed Project and Base Project, respectively. Other site uses allowed under the IR zoning, such as Dry Bulk Commodities, would not require mitigation for sea level rise. It should be noted that there are active railroad tracks and spurs that run along the east side of the site along Seaport Boulevard as well as the west side of the site crossing Blomquist Street. The proposed project does not include raising the tracks and will need to accommodate the existing location of the tracks with grade transitions between the project site fill, street, and track elevations. Similarly, while improvements will be made to Blomquist Street along the entire frontage, Blomquist Street will not be raised at this time and will require transitions from the raised site to Blomquist Street. While the city has shared they would not require the entire site to be raised, the developer has indicated that they intend to raise the entire site. Due to the large amount of upfront costs in raising the site, it would be cost prohibitive to phase construction for both the Proposed and Base Project. The developer has stated their intent is not to phase the work. See Appendix B for additional site and zoning information. UTILITY SERVICE FEASBILITY ANALYSIS The City of Redwood City had an Inner Harbor Specific Plan Utilities Engineering Report prepared for the city owned utilities around the Inner Harbor Development area, which assesses the current capacity and development potential of the on-site utilities (West Yost Associates, Page 12 1700 S. Winchester Boulevard I Campbell, CA 95008 1 P. 408.636.0900 1 F. 408.636.0999 / www.sandis.net