7915 EVERGREEN WAY 2016-01-01 MF Import

� DRAINAGE/DETEN'TION EVALUATION FOR THEPROPOSED ARCO AM/PM MINI-MARKHT LOCATED AT THE INTERSEGTION OF EVERGREEN WAY AND 79T[-I PLACE EVEREIT, WASHINGTON PREPARED FOR ARCO PRODUCI'S COMPANY NOVEMBER 16, 1989 ARCO FAC NO. 5702/OUR JOB NO. 3330 iNTCtODUCi'ION AND GENERAL INFORMATION: The proposed projcct Ges in a portion of thc southwest corner of Section 7, Township 28 North, Range 5 East of the Wiilamette Meridian in Everett, Washington (see Vicinity Map Fxhibit A). 11�e subject properry is irregutar in shape and encompasscs an area oF approximately 0.901 acres. The site is boundcd to the west by Evergreen Way. Evergreen Way provides approximately 2?S Ceet af irontage along ti�e west property boundary. The abutting propeny to the north is currently developed and occupied by a Burgcr King franciiisc. Other adjacent propertics are currenUy undeveloped. The project site is e.vrrenUy undeveloped with no appareni land use. The eristing ground cover consists of various � grasses and a dense variety of c��ergreen and deciduous trces with relatively thick undergrowrth. The site slopes ', ae northeast with approximately 16 fcet ot reiief Crom the southwest property corner to the northeast properry wrner. The proposed project is to construct a 2,700-square-foot single-story wood frame mini-market Cacility with Qie rctail disuibution of gasoline. The buildtng structure will be located along the north property line and surrounded by appropriate parking and landscaping. Since the proposecl project will inaease the impervlous surface area, consequenUy incrcasing stormwater runoff, detention will be required. Researching various city records has revealed that the subject property lies within the Pigeon Crcek No. 1 Drainage Basin which requires detentton design for a 30-year pre-development storcn ::nd a�-}ear post-development storm. The civil engineering design plan Cor this project and the b.,undary and topographic survey shown on thcsc plans have becn preparcd by the firm of Barghausen Consulting Enginc:ers, Inc. OFF-SITE DRAINAGE CONSiDERATIONS: From a site investigation and reterencing the attached Tributary Maps, it �s realized that the subject property lies within an area identified as the Pigeon Creck No. 1 Drainage Basin. This portion of the basin is isolated trom off-site stormwater runoCt As previously mentioncd, the sice is bounded to the west by Evergrcen Way. The curb and guuer provided along Evergreen Way prohibits stormwater � 3330.15 -1- ;_