3618 SHORE AVE 2023-10-24 - Laserfiche WebLink

• Everett Municipal Code 14.28 and December 2019 DOE SWMMWW 2.5.1 Minimum Requirement#1: Preparation of Stormwater Site Plans 3.1.1 Site Analysis: Volume 1, Section 3.1 Boundary Survey & Topography Map • A survey for the site has been provided by Orca Land Surveying. Vegetation and Utility Infrastructure • The existing condition of the site is developed with two single-family house, several outbuildings, and driveway areas. Existing utilities on site include sewer, water, and overhead power. Soils Report • A soils report has not been obtained by the project proponent as this application is not required to acquire one due to it's exemption from meeting the LID performance standard per section 1-2.5.5 of the 2019 DOE SWMMWW. However, a memorandum discussing the infeasibility of stormwater infiltration, has been prepared and provided by Nelson Geotechnical Associates. See Appendix A for Geotechnical Memorandum. Site Analysis and Summary of Existing Conditions • The current condition of the property is fully developed. However, all existing impervious area will be demolished before the construction of the proposed development. The site appears to be sloping moderately towards Shore Ave. No wetlands, or other critical areas exist on site. However, a steep slope within 200 ft of the subject site is within the site's immediate drainage vicinity. 3.1.2 Preliminary Development Layout: Vol 1, Section 3.1.2 A development layout has been prepared that shows the proposed short plat lot lines, location of the proposed lot 2 house, driveway, and drainage facilities. 3.1.3 Off-Site Upstream and Downstream Analysis: Vol 1, Section 3.1.3 Upstream Analysis: Areas upstream of the site appear to convey runoff into a public storm drain system. It is not anticipated that upstream areas will be negatively impacted by the development of this site. Downstream Analysis: Task 1 —Define and map the study area A Drainage Inventory map has been included in Appendix B of this report showing the combined sewer and stormwater system in Shore Ave Ave. The City of Everett GIS Utilities Map shows stormwater being routed west underneath Shore ave towards W Mukilteo Blvd. However, the survey provided by Orca Land Surveying shows stormwater flows being routed in to eastern direction of Shore Ave consistent with the topography and incrementally decreasing invert elevations of the existing catch basins in the street. Since flows cannot travel up hill it is reasonable to conclude that the City of Everett Gis Utility map is incorrect. Task 2—Review all available information on the study area