G 0 Engineering LLC <br />Storm Water Design Report <br />Project: <br />Location: <br />Date: <br />Designer: <br />Type of Project: <br />Soil Type (MRCS): <br />Project Overview <br />Wendell Canyon PUD <br />East 43rd, Eugene, OR (18-03-16-20 T.L. 700&2800) <br />November 30, 2015 <br />Scott Morris, PE <br />Residential <br />Dixon-Philomath-Hazalair complex and Panther Silty Clay Loam, per <br />Geoscience, Inc. Geotechnical Investigion <br />The proposed project is to develop approximately 7 acres of property (9.13 acre total site area) in <br />southeast Eugene with 26 single family residential houses and associated infrastructure. The site <br />has existing wetland areas which have been delineated by Environmental Solutions Inc. <br />The site is located downstream of (3) off site drainage basins and is currently providing some <br />level of detention for the stormwater run off prior to entering the public system. The stormwater <br />analysis incorporates these offsite flows into the design of the proposed development to model <br />the impact to the downstream system. <br />There is also a fourth drainage basin that flows parallel to the site and has been analyzed as part <br />of this study. <br />The development will include public roadways and roof drainage that will be directed to a series <br />of small ponds along the western side of the project. The ponds will be designed to provide <br />detention for the run off to insure flows leaving the site will be no more than the existing flow <br />leaving the undeveloped site. <br />Existing Site Drainage <br />The existing site is mostly wooded with three existing structures that are abandoned. The site <br />has slopes up to 20% with hydrologic group D soils. There are four natural drainage ways that <br />flow through or adjacent to the site as follows: <br />P:541-302-9790 Civil Engineering & Site Planning 386 Q Street <br />Oregon - Arizona - Washington Dba Olson & Morris Springfield, OR 97477 <br />