PDF Page 86 <br />Should the adjacent East Ridge PUD development not occur in a timely manner, the <br />applicant will procure and develop the Secondary Interim Access as described in the Pre- <br />Hearing submittal Exhibit 5 beginning with LaurelRidge Phase 3. <br />Should the adjacent East Ridge PUD development not occur in a timely manner to <br />facilitate later phases of t aurelRidge development (those associated with stormwater <br />basins 3, 4 and 5) additional on-site detention to attenuate flows shall be provided. The <br />detention system(s) shall be located within areas approved for impact by development <br />(outside the natural resource preservation areas) <br />9.8320(8): Residents of the PUD will have sufficient usable recreation area and open <br />space that is convenient and safely accessible. <br />The Staff Report, at page 46, explains why this standard is met. That discussion is incorporated <br />here. <br />9,8320(-9): stormwater runoff from the PUD will not create significant negative <br />impacts on natural drainage courses either on-site or downstream, including, but not <br />limited to, erosion, scouring, turbidity, or transport of sediment due to increased <br />peak flows or velocity. <br />This standard will be met by the applicant's stormwater plan, which will hold the post develop <br />peak-discharge to the pre-development rate. <br />The majority of the stormwater is being directed to existing piped stormwater systems. The <br />stormwater that is directed tQ the Goal 5 resource areas will be controlled through detention <br />facilities. Discharge from the detention facilities will be directed to designated outfall areas with <br />rip-rap pads sized appropriately for design storm peak flow rates. (See Stormwater Analysis <br />submitted June 24, 2013 by Branch Engineering at Page 2 para 6). <br />The solution proposed here for discharges to the natural drainageway is the same as was <br />imposed by the HO in the Spring Knoll PUD to address the same issue. The Hearings Official <br />found a solution for approval of this standard as follows: <br />As identified in the tentative PUD plans for all stormwater run off from the site will-be <br />directed to open waterways or to storm drainage facilities provided in Wendell Lane. <br />Lots and access roads that are unable to drain directly to the storm drainage system in <br />Wendell Lane will discharge their stormwater run off to the existing drainage channels <br />that pass through the site. Channelized outfalls to open drainage ways are erosive to the <br />banks and riparian features of the open channel. All outfalls to open drainage ways shall <br />require a building permit and shall be designed to include energy dissipation measures. <br />(See Hearing Official Decision (Spring Knoll PUD Phase 4) PDT 05-3 (November 17, 2005) <br />at page 21, Prehearing Exhibit 3-1.6.) <br />LaureiRidge Applicant Final Argument - Page 52 <br />135 <br />Laurel Ridge Record (Z 15-5) Page 890 <br />