10617 ROSEWOOD AVE 2022-01-25 - Laserfiche WebLink

• KUKHOTSKIY DUPLEX Minimum Requirement # 1: Stormwater Site Plan • Executive Summary The proposed project consists entirely of clearing and grading for the construction of a • new duplex, a corresponding driveway, and drainage improvements. The proposed duplex is to have an approximate total roof area of 3,695 sf., and new driveway and walkway areas of 1,600 sf. Drainage management for new roof area is to consist of roof drain to a 8'X15' Infiltration trench for approximately 457 square feet of roof area per BMP T5.10A, and roof drain to 5 splash blocks for approximately 3,238 square feet of • roof area per BMP T5.10B. Drainage management for new driveway area is to consist of sheet flow dispersion through adjacent lawn areas. The disturbed vegetated areas will be amended lawn per BMP T5.13. The project is to be designed to the 2019 DOE Storm Water Management Manual of Western Washington in addition to chapter 4 of the cities • 2020 Design and Construction Standards. Existing Conditions Summary • The property is one tax parcel and contains an existing SFR, and a small gravel driveway. Vegetation on-site consists mainly of residential lawn areas. Slopes on-site are flat to moderate,ranging from 2%to 8%, and sloping generally southwesterly toward the south boundary line of the site. From a Snohomish County Soil Survey done by USDA the soils • on-site consist of Alderwood-Urban Land Complex. According to soil observations by Nathan Thompson of Western Engineers and Surveyors, Inc., soils on-site resemble sandy loam type soils. Refer to Appendix II for soil information. • The adjacent parcels to the north, east, and south appear to be developed with existing SFR, driveways. All are comprised of mostly residential lawn areas with a portion of forest area and various vegetated areas. Rosewood Avenue lies along the west boundary line of the site. • • • WESTERN ENGINEERS,INC. 2 PROJECT: 19-1825-A