7007 SEAWAY BLVD 2025-07-14 - Laserfiche WebLink

Stormwater Pollution Prevention Plan 2.0 Site Description 2.1 Existing Conditions The project site is approximately 12.25-acres in area. The project consists of a portion of one parcel. The proposed project area is currently undeveloped. The parcel is bordered on the north and south by various industrial businesses and is bounded by Seaway Blvd. to the south, an industrial complex to the north and east, and a Corporate & Continuing Education Center to the west. Two existing driveways currently provide access to the site via Merrill Creek Parkway from the north and west. The majority of stormwater currently either runs off directly into Narbeck Creek offsite or flows into Narbeck Creek through overflow of wetlands. The frontage improvements lie within Powder Gulch basin. According to the USDA Web Soils Map the soils onsite consist of Alder wood gravelly sandy loam with 0-8% slopes. 2.2 Proposed Construction Activities The full build-out of this project proposes the addition of a warehouse/industrial building, paved drives, parking areas, and frontage improvements. Construction activities will include site preparation, TESC installation, clearing and grading, utilities,paving of the parking lot, construction of the warehouse/industrial building, construction of the detention vault and other stormwater facilities. re-grading and paving for proposed building pads, driveways, and parking areas. The schedule and phasing of BMPs during construction is provided in Section 4.0. Stormwater runoff volumes were calculated using the Western Washington Hydrology Model (WWHM). The following summarizes details regarding site areas: ■ Total site area: 12.25 acres ■ Percent impervious area before construction: 0% ■ Percent impervious area after construction: 79% ■ Disturbed area during construction: 12.25 acres ■ Disturbed area that is characterized as impervious (i.e., access roads, staging,parking): 9.72 acres SNBL USA, LTD—Seaway Commercial Center SWPPP 3 August, 2022