(i)EC 9.6780 Vision Clearance Area. <br /> <br />visual obstructions that would pose a hazard to the traveling public. These standards will be <br />further enforced at the time of development. <br /> <br />(j)EC 9.6791 through 9.6797 regarding stormwater flood control, quality, flow <br />control for headwaters area, oil control, source control, easements, and <br />operation and maintenance. <br /> <br />EC 9.6791 Stormwater Flood Control <br /> <br />In order to protect lives and properties from flood and drainage hazards, stormwater runoff <br />from development sites (as calculated utilizing the Rational Method and considering all <br />developments having received tentative or final plan approval) shall be discharged into existing <br />stormwater flood control facilities that have the capacity to handle the stormwater runoff; or, <br />be retained or detained onsite; or, discharged into a new stormwater flood control facility <br />constructed by the applicant. Proposed and required stormwater flood control facilities shall be <br />designed and constructed in compliance with code requirements. The applicant calculated the <br />stormwater runoff using software which utilizes the Santa Barbara Unit Hydrograph Method. <br />This method is acceptable and is considered an equivalent hydrological analysis to the Rational <br />Method. <br /> <br />Stormwater Management Plan and Drainage Study, dated March 3, 2017, <br />and stamped by Nathan Patterson, P.E., the stormwater treatment and management plan for <br />the development includes the widening of a public street, the construction of a private street, <br />and underground treatment and detention tanks. This report has identified five existing points <br />of connection/discharge: (1) the eastern gutter line on Capital Drive, (2) Hendricks Park east of <br />the development, (3) a shallow channel north of the site, (4) the western gutter line on Capital <br />Drive, and (5) the adjacent neighboring properties to the west of Capital Drive. <br /> <br />The applicant has broken the proposed stormwater management up into three initial <br />components: (1) Capital Drive runoff, (2) private roadway runoff, and (3) individual lot runoff. <br />The majority of Capital Drive currently sheet flows to the west where intermittent curb exists. <br />In areas where curb does not exist, runoff drains to discharge point (5), which are the <br />neighboring properties to the west of Capital Drive. <br /> <br />Capital Drive <br />The applicant has proposed to construct a flush curb on the west side of Capital Drive in the <br />areas where a functioning curb currently does not exist. The proposal for a flush curb is <br />consistent with existing drainage patterns. The applicant is proposing to reconstruct Capital <br />Drive to City of Eugene local street standards, which includes constructing the road to a width <br />of 21 feet. The road is proposed to be constructed in a fashion that mimics existing drainage <br />patterns and quantities, with any additional street width draining to the east gutter. There is a <br />high point in Capital Drive at approximately the middle of the site. Runoff south of the high <br />point on the east side of Capital Drive will be collected into catch basins and directed to a <br />mechanical treatment device near the southern intersection with the private roadway. The <br /> <br />Capital Hill PUD (PDT 17-1) February 2018 48 <br />Page 48 <br /> <br />