Planning Commission Agenda Packet 09092026

City of Pleasanton—Additional Housing Sites Rezonings Project CEQA Guidelines Section 15164 Addendum Addendum 97 policies, and compliance with all applicable regulations, impacts related to changes to drainage patterns would be reduced to a less than significant level. The Prior FEIR included an analysis of flood risks associated with implementation of the General Plan, including identification of flood hazard areas within the City. The Prior FEIR concluded that compliance with federal and local regulatory requirements regarding construction of new development within 100-year floodplains to reduce potential risk from flooding, including Chapter 17.08, Flood Damage Prevention, of the City’s Municipal Code, as well as General Plan policies and actions to address concerns, impacts would be reduced to a less than significant level. Proposed Project Analysis and Conclusion Future development resulting from the proposed sites would include construction that could impact existing drainage patterns and expose soils to stormwater, potentially resulting in flooding, erosion/siltation, and polluted runoff, which ultimately could impact water quality. Consistent with the analysis in the Prior FEIR, any future projects at the proposed sites would be required to comply with all NPDES permit requirements, including the preparation of an SWPPP, as well as Municipal Code Section 9.14.120, which identifies both construction and operation- related BMPs to reduce pollutants entering the City storm sewer system. Additionally, future projects would be required to comply with regulations enforced by the RWQCB. Site A and Site C are located within 500-year Federal Emergency Management Agency (FEMA) flood hazard zones, while Site B is not located within a flood hazard zone.10 Compliance with these regulations would ensure that development of the proposed sites does not violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or ground water quality. In addition, these measures would ensure that future developments do not impact existing drainage patterns or expose soils to stormwater, reducing risk of erosion, siltation, polluted runoff, and flooding. Any future projects at the proposed sites would be required to prepare a stormwater management plan in accordance with Municipal Code Section 19.14.140, which requires new developments to incorporate Low Impact 10 Federal Emergency Management Agency (FEMA). 2026. National Flood Hazard Layer. Website: https://hazards- fema.maps.arcgis.com/apps/webappviewer/index.html?id=8b0adb51996444d4879338b5529aa9cd&extent=- 121.88523674609374,37.64807200561917,-121.8582859099121,37.66505976307913. Accessed March 13, 2026.