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<br />.. <br /> <br />Exhibit A <br /> <br />. <br /> <br />Potential degradation or <br />destabilization of downstream channel <br />morphology. <br /> <br />Potential degradation of surface water <br /> <br />. <br /> <br />quality from <br />increased <br />sedimentation, <br />construction. <br /> <br />site activities, <br />turbidity <br />particularly <br /> <br />such as <br />from <br />during <br /> <br />Potential dewatering impacts, such as <br />slope sloughing during construction <br /> <br />Change in stormwater runoff volumes <br />and characteristics as a result of project <br />implementation. <br /> <br />. Potential of over-exerting existing <br />storm drain and flood control <br />infrastructure as a result of increased <br />runoff upon implementation of the <br />proposed project. <br /> <br />. <br /> <br />. <br /> <br />If hydrological impacts associated with the <br />proposed project would be significantly <br />greater than those associated with the <br />Specific Plan, EIP will recommend specific <br />mitigation measures for all significant <br />impacts. <br /> <br />The environmental setting will be based on <br />documents available from public agencies, <br />such as the Department of Water Resources, <br />United States Geological Survey, and the <br />City. The environmental setting will also <br />include a description of federal, State, and <br />local regulations pertaining to hydrology and <br />water quality. Approved drainage area and <br />stormwater management plans of the City <br />and the Alameda County Flood Control and <br />Water Conservation District, applicable <br />codes and ordinances, and State and Regional <br />Water Quality Control Board plans and <br />associated C.3 provisions will be consulted <br />regarding their policies and practices <br />applicable to the proposed project. <br /> <br />The impact analysis will involve both <br />quantitative and qualitative evaluation of the <br />proposed land use changes at the project site. <br />EIP will quantify the impact of the proposed <br />project on storm water flow and flood <br />characteristics. Assuming input data are <br />readily available from the City, the County, <br />and the applicant, EIP proposes to apply <br />HEC-HMS and HEC-RAS, to compute the <br />hydrograph at the project site and projected <br />surface water elevations for the lOO-year <br />storm event. The hydrograph provides <br />information about flow over time, peak <br />flow, and infrastructure capacity deficiencies. <br /> <br />If stormwater best management practices <br />(BMPs) for water quality and quantity are <br />included in the project design and site plan, <br />EIP will evaluate their potential effectiveness <br />at reducing potential impacts. If an impact is <br />found to be significant or potentially <br />significant, after implementation of all <br />project design features, mitigation measures <br />that conform to the City's and County's <br />drainage and stormwater management plans <br />or other regulations and guidances) will be <br />proposed. EIP will recommend appropriate <br />mitigation measures, such as stormwater <br />quality BMPs, to minimize potential impacts. <br />This may include suggestions about site <br />selection for siting detention basins; site <br />design techniques to minimize impervious <br />surfaces; use of natural swales and biofilters <br />to treat polluted stormwater; incorporation <br />of pervious pavement or cement to minimize <br />runoff; implementation of structural and <br />non-structural BMPs; and other means for <br />reducing the rate and volume of stormwater <br />runoff and for treating stormwater to <br />remove potential pollutants. Recommended <br />BMPs would be consistent with the National <br />Pollutant Discharge Elimination System <br />Permits, the Stormwater Pollution <br />Prevention Plan for construction activities <br /> <br />EIP Associates <br /> <br />2-16 <br />