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2 Environments 7.B. - Page 63 <br /> Type of Square <br /> Activity Excavated/ Location Feet Volume Linear <br /> Fill Material (sq ft) (cY) Feet Of) <br /> Install RSP for Fill/ RSP Creek bank below stormwater 32 2 4 <br /> stormwater outflow pipes,under the US 101 <br /> discharge pipes overcrossing <br /> Install retaining Excavation/ Creek bank below US 101 146 10 120 <br /> wall bank soil overcrossing <br /> Install retaining Fill/ bank soil Creek bank below US 101 0.03 170 175 <br /> wall overcrossing <br /> The new pump station would have an outflow discharge rate of 32.40 cfs through the existing 24- <br /> inch storm drain leading into Redwood Creek. The peak outflow discharge rate would increase from <br /> 4.3 feet per second (fps) to 10.3 fps,during extreme storm events. Because of the length of the <br /> existing outflow pipe,there would not be any impacts to the bed and bank of Redwood Creek <br /> associated with the increased flow. <br /> The proposed cofferdam in Mitigation Measure BIO 1 and the erosion control measures in <br /> Mitigation Measure BIO 7 would avoid or reduce the potential for construction activity to affect <br /> wetlands and jurisdictional waters. With the implementation of the proposed BMPs and mitigation <br /> measures, the activities would not have a substantial adverse impact to protected wetlands and <br /> jurisdictional waters. (Less than Significant Impact with Mitigation Incorporation) <br /> d)Interfere substantially with the movement of any native resident or migratory fish or <br /> wildlife species or with established native resident or migratory wildlife corridors, or impede <br /> the use of native wildlife nursery sites? <br /> The proposed activities would not interfere with the movement of migratory fish or animal species. <br /> The creek bank is barren and subject to human disturbance. Redwood Creek is not a migratory route <br /> for steelhead. The area of temporary dewatering is tidal and typically exposed during daily low tides. <br /> The temporary cofferdam would minimize the hydroacoustic effects to EFH and fish species that <br /> have a potential to occur in the adjacent areas of the creek (see Mitigation Measure BIO 1). <br /> The increase in the discharge from the pump station would occur during peak storm events when <br /> there are high flows in the creek. Under these conditions, the proposed increase would not have a <br /> significant effect on resident or migratory fish species. (Less than Significant Impact with <br /> Mitigation Incorporation) <br /> 2-23 US 101 Pedestrian Undercrossing and Bair <br /> Island Road Storm Drain Pump Station Project <br />