18 ATTACHMENTS - Laserfiche WebLink

Pleasanton Gateway Environmental Checklist Less'rhan Potentially Significant Less Than Significant With Mitigation Significant No Issues (Continued) Impact Incorporated Impact Impact c) Substantially alter the existing drainage pattern of the ^ ^ 0 ^ site or area, including through the alteration of the course of a stream or river, in a manner, which would result in substantial erosion or siltation on- oroff-site`? d) Substantially alter the existing drainage pattern of the ^ ^ ~ ^ site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner, which would result in flooding on- or oft=site? e) Create or contribute runoff water which would exceed ~ ~ ~X the capacity of existing or planned stormwater drain- age systems or provide substantial additional sources of polluted runoft7 ~ Otherwise substantially degrade water quality? ~ ~ ^X g) Place housing within a 100-year flood hazard area as ~ ~ ~ ~X mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? h) Place within a 100-year flood hazard area structures, ~ ~ ~ X^ which would impede or redirect flood flows? i) Expose people or structures to a significant risk of Loss, ~ ~ ~ ~X injury or death involving flooding, including flooding as a result of the failure of a levee or dam? j) Inundation by seiche, tsunami, or mudflow? ~ ~ ~ ~X Discussion a,e,f) The landscape areas facing Stanley Boulevard, Bernal Avenue, and Nevada Court are designed and graded to function as bio-retention swales. The paved areas of the site are graded to drain towards the bio-retention swales and then to catch basins within the swales before entering the City's storm drain system. The project will be required through the building permit and construction process to incorporate best management practices for discharges resulting from this development. The City has adopted the most recent Regional Water Quality Control Board stormwater discharge requirements re- Pleasanton Gateway Initial Study Page 25 of 37 Novetnber 8, 2006