10725 19TH AVE SE 2023-04-07 - Laserfiche WebLink

II. Site Assessment: The project site was developed with a single-family house and detached outbuilding. Existing vegetation consists of landscaping, low brush,grass and bushes.The site is accessed from 19th Avenue SE. The site generally flat with some local 2%slopes and contains no wetlands,creeks or streams. The site is within a neighborhood that consists of both multi-family and single-family homes. There might be a nominal amount of tributary runoff entering the site from the north. Existing storm sheet flow over the site toward an existing storm system on 19th Avenue SE. Similarly,the developed storm runoff from the entire site will flow toward onsite detention tank and released to an existing storm system on 19th Avenue SE. Review of all available information: Conducted site review and reviewed available information from the City of Everett and Snohomish County mapping system and found no critical areas,erosion or landslide hazard areas within quarter mile of the project site. Also,there are no streams,wetland or flood areas. Also there are no water quality issues has been identified. The soil hydrologic types for this site have been Also identified as Type C from the Snohomish County Soil Survey Map. This soil, Alderwood Urban Complex,this soil is moderately deep and moderately well drained over hardpan. More detailed soils information provided as part of the geotechnical engineering evaluation prepared by Nelson Geotechnical Associates, Inc. III. Site Development Plan w/On-Site Stormwater Management: The project proposes to manage stormwater runoff on site to the maximum extent. Flows from building's rooftops will be collected and directed to a detention tank. Most of the site soils will be disturbed during construction. The area where soils have been disturbed,the soil will be amended according to the following procedures: 1. Scarify subsoil to a depth of one foot. 2. In planting beds,will place three inches of compost and till in to an eight-inch depth. 3. In turf areas,will place two inches of compost and till in to an eight-inch depth. 4. Apply two to four inches of arborist wood chip,coarse bark mulch,or compost mulch to planting beds after final planting. During construction,the following strategies will be considered on the project site: 1. Retaining the duff layer,native topsoil,and natural vegetation in an undisturbed state to the maximum extent practicable. 2. Retaining to the maximum extent practicable the features on the site that provide natural stormwater management. 3. Maintaining predevelopment flow path lengths and natural drainage patterns whenever possible. 4. Keeping distances for overland flow short to promote sheet flow and minimize concentration of runoff 5. Managing stormwater as close to its origin as possible.