Attachment B <br />erosion, scouring, turbidity, or transport of sediment due to increased peak flows or velocity. <br />Staff Findings <br />The site contours indicate that the subject property currently sheet drains to the east. The <br />applicant proposes to maintain the existing drainage patterns by directing overflow from the <br />proposed on-site stormwater management facilities toward the east property line, abutting the <br />City parkland. The on-site stormwater management facilities consist of piped collection and <br />conveyance systems that are interspersed with pollution-reduction facilities, which include <br />filtration rain gardens abutting the dwellings and a vegetated Swale in the common open <br />space. The overflow to the parkland will be dispersed evenly toward the east property <br />boundary with four outfalls that are designed to reduce flow volumes and velocities. <br />Referral comments from Public Works staff confirm that the overflow to the parkland is <br />acceptable, provided the flow is not concentrated or otherwise cause damage to the City's <br />property. The preliminary design information provided by SSW Engineers confirms that the <br />development will meet this expectation, as well as the stormwater development standards at <br />EC 9.6791 through EC 9.6797, which is addressed in detail at EC 9.8320(11)(j) and is <br />incorporated here by reference. <br />Based on these findings, the development will comply with this criterion. <br />Opponent Arguments <br />As noted above, in the findings for EC 9.8320(6) the neighbors raised concerns about the <br />quantity of stormwater and how it will be treated and discharged. Questions were raised <br />about how the discharge onto the adjacent open space to the east would be modulated to <br />mimic pre-development levels. <br />Hearings Official Conclusions <br />The Hearings Official generally concurs with Staff's findings for EC 9.8320(9) and adopts those <br />findings by this reference. The findings supporting EC 9.8320(6) are also incorporated here by <br />this reference. <br />The application materials and Staff's findings explain that treated stormwater will be <br />discharged onto the adjacent City open space to the east of the proposed PUD. The record <br />shows that the city agreed to allow this discharge. There are no "natural drainage courses" in <br />that area, and neither the record nor any evidence submitted by the neighbors indicates that <br />erosion is anticipated to result from the discharge of treated stormwater. <br />EC 9.8320(10): Lots proposed for development with one-family detached dwellings shall <br />comply with EC 9.2790 Solar Lot Standards or as modified according to subsection (11) below. <br />Hearings Official Decision (PDT 13-1, WG 13-1) 32 <br />