2201 EVERETT AVE SEPA 018 - 008 Drainage Report 2025-04-15

INTRODUCTION This project is for the demolition of an existing concrete block single story office/ Wearhouse building and construction of a three story Mini Storage Building. Currently the site and frontage along Everett Ave are entirely coved with impervious surfaces. This project will lower the impervious surface area for this site and right-of-way by providing Lawn and Landscaping areas. The site is within the combined City of Everett stormwater and sewer area for additional information see the Attached Combined System Map and Public Works Policy#: 2-11 Attached to this report. The site is exempt from Minimum Requirement#6—Runoff Treatment by reducing the impervious surface area. Two Bio retention areas have been provided the developer to reduce flows and water quality requirements and be credited against the project's sewer connection charge (EMC 14.08.135) The site is subject to the requirements of the City of Everett 2010 Stormwater Management Manual and the Washington State Department of Ecology's 2012 Stormwater Management Manual for Western Washington, as amended in 2014 (2014 SWMMWW). This report is intended as satisfying the Minimum Requirements 1 through 5 for the City of Everett Stormwater Management Manual. Minimum Requirement#1: Stormwater Site Plan Preparation See attached Drainage, C-SWPPP and Site Plan as prepared by BRL Services LLC dated 6/1/18 The project is for the construction of a three-story mini storage building on a 0.78-acre site. Less than 1 acer of land disturbance will be required for this development. Existing structures will be removed from site. The soils found onsite are Alderwood- Urban land complex. The following is a breakdown of pervious and impervious surfaces: Site Area =34,718 sf =0.78 ac(no ex. pervious surface) Existing Building = 17,479 sf =0.40 ac New Building = 18,500 sf =0.43 ac Frontage Landscape = 2,963 sf =0.07 ac(new pervious surface) Parking & Driveway = 13,255 sf =0.21 ac R/W to Ex Flow Line = 8,168 sf =0.19 ac (no ex. pervious surface) Right of Way Landscaping = 3,019 sf =0.07 ac (new pervious surface) Pre and Post Basin Area =0.97 ac Minimum Requirement#2: Construction Stormwater Pollution Prevention For additional information see the SWPPP prepared for the Washington State Department of Ecology Prepared by BRL Services LLC Brian R Lindsay(CESCL)dated 6/4/18.