Planning Commission Agenda Packet 09092026

City of Pleasanton—Additional Housing Sites Rezonings Project Addendum CEQA Guidelines Section 15164 Addendum 98 Design (LID) features such as bioretention. On-site stormwater management systems would be designed with project site conditions, such as flood hazard zones, taken into account. Further, because the proposed sites contain existing development, future redevelopment projects would likely improve the stormwater conditions through compliance with the most up-to-date stormwater system standards. Further, preparation of a stormwater management plan would ensure that developments on the proposed sites are designed to reduce the risk of flooding and impeded or redirected flood flows. Compliance with the Municipal Code, the General Plan, and NPDES permits would ensure that stormwater and drainage patterns are sufficiently managed such that water quality is not significantly degraded. Therefore, impacts would be less than significant, and the proposed project would not result in a new or more severe adverse impact that was not previously identified and disclosed in the Prior FEIR. No further analysis is required. b) Groundwater Would the project: Substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin? Summary of Prior FEIR Water supplies for the City are managed by Zone 7 of the Alameda County Flood Control and Water Conservation District (Zone 7). Roughly 20 percent of Zone 7’s water supply is groundwater. Zone 7 acquires more than 80 percent of its raw water supply from the California State Water Project (SWP), a multi-purpose water storage and delivery system comprised of canals, pipelines, reservoirs, and hydroelectric power facilities that extends more than 705 miles. SWP surface water is treated at the Patterson Pass Water Treatment Plant (PPWTP) and the Del Valle Water Treatment Plant (DVWTP) and is conveyed through a network of Zone 7 Water Agency transmission pipelines to the City’s service areas and other retail customers. According to the Prior FEIR, the Zone 7 Water Agency has adopted a Water Supply Reliability Policy to maintain the ability to meet 100 percent of Zone 7’s estimate for treated water demands for 100 percent of the time; as such, and given compliance with applicable General Plan policies and the voluntary and mandatory water conservation requirements during water shortages established in Chapter 9.30 of the City’s Municipal Code, the Prior FEIR concluded that impacts related to groundwater supply and recharge would be less than significant.