RES 00111A - Laserfiche WebLink

Mitigation Measures Measure B 1 a. Provide for on-site detention/retention of storm waters to offset the effects of the increase in runoff to the Arroyo resulting from site development, and prepare a maintenance plan for detention/re[ention facilities. Measure Blb. The detention/retention facilities should be operated to contain and release runoff at a rate consistent with the Zone 7 Master Plan. Findines: Changes or alterations have been required in, or incorporated into, the Project which avoid or substantially lessen the significant environmental effect identified in the Final EIR to a less than significant level. Facts in Sunnort of Findine: The impact will be avoided or reduced based on the following: a. Adequate facilities shall ensure that the GHCBI Project does not increase the peak run-off These include the creation of a natural creek in the Central Pazcel running south along I-680 to a detention pond, and the creation of other detention ponds. b. The GHCBI Project features and facilities have been designed to accommodate runoff, including retention facilities capable of retaining project runoff in the 100-year storm event. c. PUD Condition and Specific Plan Storm Drainage Policy 2, Guideline 2.l require that all storm drain improvements must be based on storm water runoff modeling demonstrating sufficient capacity, and storm drain detention basins must detain peak runoff anticipated under 100-year storm events. d. PUD Condition _ requires a long-term maintenance plan for the detention ponds, which will ensure that the storm drainage improvements are managed and operated as required. 2. Imuact B3. Localized flooding may occur due to storms in excess of design capacities of side channels or culverts. Mitigation Measure: Measure B3. Design subdivision (channels, culverts, streets, open spaces, retention basins, and site grading) in a comprehensive manner such that no habitable buildings aze subject to flooding in a 100-yeaz storm event.