AgdaPkt 2016-04-25 Closed and Joint SA PFA

Browse Search

2 Environments 7.B. - Page 81 h)Expose people or structures to a significant risk of loss,injury or death involving wildland fires,including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? According to Figure PS-6 in the City General Plan,the project area is not within a Fire Hazard Severity Zone (City of Redwood City,2011). Therefore, the proposed project would not have any impacts from wildland fires. (No Impact) 2.9 HYDROLOGY AND WATER QUALITY The Location Hydraulic Study Report in Appendix H summarizes the floodplain management regulations,describes the existing floodplain conditions in the project area, evaluates potential flooding hazards from the proposed project,and details conformance with the applicable requirements. The Water Quality Report in Appendix I summarizes the water quality regulations and guidelines, describes the quality of surface waters in the area, evaluates potential project impacts of the project to water quality,and includes measures that will be implemented to maintain water quality objectives. Average annual rainfall in the City is approximately 19.16 in. (Western Regional Climate Center, 2012). The project is adjacent to Redwood Creek,a 9.5-mile long perennial stream that drains a watershed in the Emerald Lake Hill area and discharges into San Francisco Bay at the Port of Redwood City. The portion of the creek at US 101 within the project area is tidally influenced. Based on the nearest gauge, the MHHW elevation is 7.4 feet above sea level, and the Mean Lower Low Water (NILLW) elevation is -0.8 feet (WRECO,2013). Higher and lower water levels occur in Redwood Creek,depending on tidal cycles and stormwater events. According to the Flood Insurance Rate Map (FIRM) 0301E,the project area would be located within a 100-year flood zone, Zone AE, with a base flood elevation of 10 feet (FEMA,2012). The San Francisco Bay Conservation and Development Commission (BCDC) and California Department of Water Resources (DWR), estimate that continued sea level rise will increase the water level in the San Francisco Bay by 16 inches (1.3 feet) by 2050 and 55 inches (4.6 feet) by 2100 (DWR, 2011). The existing Bair Island Road pump station at end of East Bayshore Road receives stormwater from a 22.28-acre area on both sides of Bair Island Road and discharges to Redwood Creek through an existing 24-inch storm drain pipe approximately 25 feet northeast of US 101 (KPFF 2008). The existing pump station has a discharge rate of 13.37 cfs,which is inadequate for the 32.40 cfs peak flow from the 100-year storm. Redwood Creek is within the Santa Clara Valley Groundwater Basin and in the San Mateo Plain Groundwater Basin (Basin Number 2-9.03). The National Resource Conservation Service Web Soil Survey for the project area indicates that that the depth of the groundwater table is more than 6.5 feet deep (WRECO, 2013). CE&G detected groundwater at 2 to 4 feet during its boring.WRECO 2-41 US 101 Pedestrian Undercrossing and Bair Island Road Storm Drain Pump Station Project