3531 NORTON AVE 2022-02-23 - Laserfiche WebLink

2. EXISTING CONDITIONS SUMMARY The entire property consists of 0.47 acres. Runoff generated from the existing site sheet flows in the easterly direction. This project will not affect any off-site flows from passing through or around the site as in the existing conditions. Land use around the site is primarily single-family homes. The parcel associated with this project currently contains a paved driveway and parking pad on the west side of the site. Vegetation consists of brush and trees. The slope of the site in the area of the proposed duplex is relatively level with a shallow depression area (to be filed and compacted). The slope of the east side of the site is steep and averages approximately 34% down to the east. Geo Group NW performed a site visit and concluded that the site appears to have stable slopes, however loose fills at the west half of the site should be compacted. Refer to field report in Appendix A. The field report prepared by Geo Group Northwest indicates that the site soils consist of glacial till soils that are very dense. Soils logs were also provided by Brent Hackney Designs, which indicated the soils consisted of loamy fine sand and mottling found at a depth of 50-55 inches below grade. The USDA Web Soil Survey maps the soils as Alderwood gravelly sandy loam and Alderwood-urban land complex. General site slopes average approximately 34% percent(See field report prepared by Geo Group Northwest in Appendix A of this report). Based on the existing soil information and the setbacks of the proposed improvements from any of the property lines or critical areas there is little potential for erosion or sedimentation during construction assuming the basic BMPs included in the SWPPP are installed and maintained properly. Refer to Figure 2 for an existing basin map. Grandview Ave Duplex 18-1001 January 2019 'a3& 5 h5