6201 ASSOCIATED BLVD BASE FILE 2018-03-29

Wrz 1.0 INTRODUCTION This report is to serve as a project specific update to a previously prepared stormwater site plan dated February 11, 2010. This site plan was accepted by the City of Everett, effectively vesting the project in the 1992 Drainage Manual. 1.1 PROJECT DESCRIPTION The proposed Underwood Gartland Everettt project is located on Associated Blvd at the intersection with Industry Street in Everett, Washington 98203 within Sections 11, Township 28 North, Range 4 East. The 30.84-acre project site is located within the north end of the approximately 141 acre CEMEX property. The site is bound by Associated Boulevard to the west, Merrill Creek Parkway to the north and Glenwood Ave. to the east. The project site was formerly part of CEMEX's sand and gravel mining operations. The site generally slopes from the southwest to the northeast at 5 percent. The site was prepared for this specific development during the reclamation process. The proposed project will be completed in phases. Phase 1 encompasses the north portion of the 30.84 acre site. Phase 1 includes necessary parking and utility improvements to support construction of a 200,000 square foot building. Phase 2 includes installation of utilities and paving to support the construction of another 200,000 square foot building. The site will take access from Associated Boulevard. This report addresses the proposed project by examining the pre-developed and post-developed stormwater runoff characteristics of the site, and providing mitigating measures to compensate for potential impacts resulting from the development. In 2001, a regional infiltration/detention facility was constructed at the intersection of Associated Boulevard and 60th St SW for the future development of the CSR — Mountain View Business Park. This business park has not achieved full build out. In order to verify the pond's tributary "development" area of 66.9 acres, which has not been altered, a Pond Basin Balancing Analysis was completed. The proposed project will result in a tributary pond basin area of 64.93 acres (see Figure 2). The 66.9 acre pond "development"basin is within three pre-mining drainage basins: Merrill and Ring Creek, Glenwood Creek and Pigeon Creek. To comply with the City of Everett's stormwater requirements that no more than 5,000 square feet of a drainage basin's area be diverted into another basin, a Pre-Mining Basin Balancing Analysis was also completed (see Figure 3). The proposed project will meet the City of Everett requirements. DAVID EVANS AND ASSOCIATES,INC. UNDERWOOD GARTLAND EVERETT FEBRUARY 3,2015 STORMWATER SITE PLAN PAGE 1