Laserfiche WebLink
South Coast Technology Center Project <br />CEQA Exemption 15183 <br />4.10 Hydrology and Water Quality <br />4.10.1 GPU PEIR Findings <br />The GPU PEIR concluded that compliance with local, state, and federal regulations and the <br />policies of the proposed General Plan Update would reduce buildout impacts related to <br />groundwater, drainage, hydrology, and water quality. Individual projects would be required to <br />incorporate project -specific source control and treatment Best Management Practices (BMPs), <br />incorporate low impact design (LID)/site design, and comply with applicable regulatory <br />requirements to ensure compliance with regulations governing water quality, including the <br />following: <br />• Santa Ana Local Implementation Plan [LIP] <br />• Orange County Drainage Area Management Plan <br />• Construction General Permit (CGP) Water Quality Order 2009-0009-DWQ for preparation <br />of a Stormwater Pollution Prevention Plan (SWPPP) (RR HYD-1) <br />• National Pollutant Discharge Elimination System [NPDES] Municipal Separate Storm <br />Sewer System [MS4] Permit from the Santa Ana Regional Water Quality Control Board <br />(RR HYD-4) <br />• Santa Ana Model Water Quality Management Plan [WQMP] <br />• Santa Ana Municipal Code (RR HYD-5) <br />• General Industrial Permit (Order No. CAS000001) for industrial activity (RR HYD-2) <br />preparation of a Water Quality Management Plan). <br />Additionally, the GPU PEIR determined that projected water demand from the proposed GPU at <br />buildout is well within the projected total water demand for 2040 in the 2015 urban water <br />management plan for normal, dry year, and multiple dry year scenarios. Related to pervious <br />surfaces and runoff, the GPU PEIR also determined peak flows would be decreased overall but <br />an increase of stormwater runoff peak flow rates could result from the introduction of new <br />impervious surfaces. As stated in the GPU PEIR, the City and County have policies in place for <br />reviewing and permitting new developments including requiring detailed hydrology studies. <br />Related to flood hazards, tsunami, and seiche zones, the GPU PEIR determined that impacts <br />would be less than significant due to the low potential for such conditions to occur and the <br />regulations in place to manage flood hazards and minimize flood risks. In summary, the GPU <br />PEIR determined that all impacts related hydrology and water quality would be less than <br />significant and that no mitigation measures were required. <br />4.10.2 Project Analysis <br />The Project would redevelop a 10.2-acre office park and develop an approximately 5.6-acre <br />vacant field. Construction activities have the potential to degrade water quality through the <br />exposure of surface runoff to exposed soils, dust, and other debris at the Project Site as well as <br />increase erosion and/or siltation. The proposed Project would be required to comply with various <br />applicable regulatory requirements governing water quality, including the requirements to <br />incorporate project -specific source control and treatment BMPs and the requirements to <br />incorporate low impact design (LID)/site design. For construction, the proposed Project would <br />July 2024 Page 69 <br />