J <br />(h) EC 9.6775 Underground Utilities. <br />The applicant's written statement indicates that all proposed utilities will bi; installed underground <br />consistent with this standard. <br />(i) EC 9.6780 Vision Clearance Area. <br />Public Works staff confirms that the proposal will not conflict with vision clearance area requirements. <br />No development is proposed within the vision clearance areas. Future development on corner lots will <br />be reviewed for compliance with vision clearance area requirements as part of the building permit <br />process <br />(j) EC 9.6791 through 9.6797 regarding stormwater destination, pollution <br />reduction, flow control for headwaters area, oil control, source control, <br />easements, and operation and maintenance. <br />With regard to EC 9.6791 Stormwater Destination, the applicant is proposing a stormwater collection <br />and conveyance system for the eastern portion of the site, which drains to the existing storm drainage <br />manhole located in Sterling Woods Drive, adjacent to the south boundary of the subject site. From <br />there, the stormwater will be conveyed to a 30-inch storm drain pipe that nuns to the west within a <br />public drainage easement over the vacant city park site and discharges to an outfall to the Gilham open <br />waterway within the /WR conservation area south of the site. With respect to the proposed <br />conveyance system; Public Works staff notes that the findings-and analysis provided in the, written <br />statement (pp 72-80) and in the an analysis of pre- and post-development flows stamped by Douglas <br />Schwinn, P.E. in exhibit J2 of the written statement includes conflicting and incomplete information, <br />but are sufficient to demonstrate the proposed conveyance system, conceptually, has adequate capacity <br />apart from impacts resulting from the proposed culvert crossing within the Gilham.waterway. Public <br />Works staff anticipates that the applicant would be able to demonstrate capacity with additional <br />analysis. The hearings official concludes that there is sufficient evidence in the record to support a <br />finding that stormwater drainage from the eastern 15 lots can be accommodated by connecting to <br />existing stormwater systems and by installing drainage systems consistent with city standards. With <br />respect to development west of the eastern arm of the riparian corridor, the hearings official finds that <br />if the applicant demonstrates that the stormwater can be accommodated in soakage trenches, or <br />through SDR review for stormwater outfall into the riparian corridor, this standard can be satisfied. <br />In regards to EC 9.6792 Stormwater Pollution Reduction, the applicant's written statement indicates <br />that "The proposed stormwater collection system will collect all runoff from proposed streets, lots, and <br />residential improvements located on the east side of the riparian corridor. This runoff will be directed <br />through an approved storm treatment manhole or similar mechanical device to remove oils and solids <br />before discharging to the existing drainage system. With respect to stormwater pollution requirements <br />for the proposed conveyance system, Public Works staff confirms that mechanical treatment is feasible <br />and could be addressed through the PEPI review process, assuming clarifying notes are provided on <br />the final PUD site plans to ensure compliance. <br />With respect to EC 9.6797 Stormwater Operation and Maintenance, the applicant indicates that these <br />requirements will be addressed at the time of final design and maintains that the standards do not apply <br />directly to the PUD because all new facilities will occur as part of the PEP] process in the future. Staff <br />concludes that the standards apply and will be satisfied subject to the condition that the final site plans <br />Alder Woods PUD (PDT 07-5 & SDR 08-2) Page 32 <br />J <br />Laurel Ridge Record (Z 15-5) Page 1160 <br />