9630 EVERGREEN WAY 2018-01-02 MF Import

II. OFFSITE DRAINAGE A. UPSTREAM DRAINAGE The upstream drainage contribution to this site is negligible. The only up - gradient property is at the west property line. This is the Holly Drive right- of-way that will be improved with new curb, gutter and sidewalk. These improvements catch the runoff from the road before it enters the site. It will be piped into the pond using catch basins and piping within the new curbline. The property to the north drains to the east and not onto the subject site. The property to the south is down -gradient. The east property line is Evergreen Way, which is the discharge point for the site and has its own drainage system. DOWNSTREAM DRAINAGE The drainage from the site will be discharged into an existing 12" drainage system located within the western edge of Evergreen Way. This 12" storm drain piping flows to the north along Evergreen Way. It flows for approx. 2500 ft. along the Highway before turning east and into North Creek. North Creek is drains into the Sammammish River and is within the Lake Washington Drainage Basin. Maps of the downstream drainage system are attached to this report.