9509 19TH AVE SE 2018-01-02 MF Import

Everett LDS Parking Lot Expansion Storm Drainage Report 1. Project Overview This document is ir.tended to provide engineering information necessary to support the construction plan application to the City of Everett for a parking lot expansion at an existing LDS Church site. The site covers 4.75 acres, most of which is already developed as part of the church facility. The site is bounded on the north by a commercial site, on the east by single family residences and on the south by single family residences. The west boundary is 19th Ave SE (SR 527). A motel is across 19th Ave. from the Church. This project proposes to expand the parking facilities on the site by replacing a grassy area on the east side of the site with additional parking. This will require the construction of the new parking area, and an expansion of the existing stonnwater facilities. A Detention Tank (duel underground pipes) system is provided for this project to provide streambank erosion control. A SlormFlller catch basin will be utilized to provide runoff treatment for the water leaving the detention system before it is discharged from the site. To accommodate some parking changes, and a trash storage location, small paving revisions are proposed near the northeast and southeast comers ofthe church building. These changes are so small compared to the ^xisting site drainage basin that they are considered de minimus in effect on the existing drainage system and have not been included in the calculations The site is located in the City of Everett at 9509 19th Ave S.G. on the east side of the road. It is within the city limits, in the NW '/, of the SW Y. of Section 17, Township 28N, Range 5E, Willamette Meridian. See Figure l - Vicinily Map. 'I i �3 1 f. Everett Mall i L, 7 Figure I — Vicinity Map LOS r •�r'i r [L I 1M+1 t'r�l a r r,t P:Q006106113 Eve'ett LDS Perking LOIJea\Smun Fep.,w06113 Deenige Report Revised U1.10.08Aoc Page 1 of 36