3_Exhibit C_ADDENDUM ONLY - Laserfiche WebLink

City of Pleasanton—Stoneridge Mall Residential Project Section 15183 Checklist/15164 Addendum CEQA Checklist FirstCarbon Solutions 131 Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480017/Consistency Checklist/21480017 Stoneridge Mall Residential Project Checklist Addendum_Updated.docx Prior EIR Conclusions The Prior EIR determined that buildout of the Housing Element could affect drainage patterns and create new impervious surfaces that cause changes to stormwater flows that could result in subsequent changes to flood flows. However, the Prior EIR noted that development proposals, including grading and drainage plans, would be reviewed by the City’s Engineering Division of the Community Development Department for compliance with City ordinance codes regarding flooding and drainage (including properly sized storm sewers and building within Federal Emergency Management Agency [FEMA] flood hazard zones). Combined with compliance with the C.3 provision of the ACCWP NPDES Permit mentioned above, the Prior EIR concluded that impacts related to flood flows would be less than significant. Analysis of Proposed Project The project site is not located in an area with flood risks according to the FEMA National Flood Hazard Layer.65 Consistent with the Prior EIR, implementation of the proposed project would require approval of grading and drainage plans. The proposed project would reduce the amount of impervious surfaces on the project site from 239,773 square feet to 220,438 and would introduce extensive landscaping, multiple bioretention areas, and new storm drainage lines along the north and west boundaries of the project site (Exhibit 9). Therefore, the proposed project would reduce on-site impervious surfaces and, through the implementation of grading and drainage plans, would ensure proper on-site stormwater management and no net increase in off-site stormwater flows. Impacts would continue to be less than significant and no mitigation is necessary, consistent with the Prior EIR. There are no proposed changes, new circumstances, or new information that would cause new or more severe impacts. Therefore, there are no environmental effects that are peculiar to the proposed project or the parcels on which the proposed project would be located. 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 in the Prior EIR. d) Risk of Pollutant Release Due to Inundation Prior EIR Conclusions The Prior EIR identified multiple sites for potential buildout under the proposed project that are near water bodies. In addition, it identified large portions of the City as located within a 500-year flood zone. One development site is partially within a 100-year flood zone. However, th e project site is not located in this area. In addition, Chapter 17.08 of the Pleasanton Municipal Code requires elevation of new residential structures to be 1 foot above base flood elevation or at least two feet if the base flood elevation is unknown unless floodproofed. Development proposals, including grading and drainage plans would be reviewed by the City’s Engineering Division of the Community Development Department for compliance with City ordinance codes regarding flooding and drainage (including properly sized storm sewers and building within FEMA flood hazard zones). Additional measures 65 Federal Emergency Management Agency (FEMA). 2009. FEMA’s National Flood Hazard Layer Viewer. Website: https://hazards- fema.maps.arcgis.com/apps/webappviewer/index.html?id=8b0adb51996444d4879338b5529aa9cd. Accessed November 22, 2022.