1815 13TH ST SEATTLE CHILDRENS NORTH CLINIC 2019-07-08

MAGNUSSON KLEMENCIC ASSOCIATES ■ ■ Approximate earthwork volumes— 1,325 bank cubic yards of excavation and 307 bank cubic yards of fill for the North Site Project. EXISTING SITE CONDITIONS The site is currently developed with the CUP building in roughly the center of the site, a temporary paved parking area on the eastern portion of the site, a paved parking area south of the CUP building, paved access roads and a two cell detention pond in the northeast corner of the site. The existing topography, vegetation and drainage are described below. TOPOGRAPHY Generally the site slopes inwards from the northwest and northeast corners, and then maintains a steady slope south to the lowest point on the site, near the access driveway at the middle of the southern property limits along 13th Street. The site is lower than adjacent parcels on the north, east and west sides of the property. Slope transitions from adjacent parcels to the property occur all on the project site and are flatter than 3 horizontal to 1 vertical. VEGETATION Various landscape areas make up the existing pervious areas and range from turf lawn and ground covers around the parking areas to well established shrubs and trees within the landscape buffer surrounding the site. DRAINAGE All impervious surface flows are collected by catch basins or swales. Landscape areas are sloped to drain to impervious areas. Flows for pervious areas are also collected a series of underdrains. All stormwater flows are directed, via a closed conveyance system to an existing two cell detention pond at the northeast corner of the site. An existing flow control structure limits the release rate from the detention pond. The flow control outlet discharges to an existing City of Everett 21-inch combined sewer located in 12' Street. ADJACENT AREAS Areas adjacent to the site include residential developments to the north and east of the site, a medical office building to the east and 13th Street directly to the south. There are no streams, lakes or wetlands adjacent to the site that will be affected by construction. Downstream drainage from the site is via the existing combined sewer to the sewage treatment plant. CRITICAL AREAS There are no critical areas within 1/4 mile or adjacent to the North Site project as defined by Chapter 37, Critical Areas, of the Everett Municipal Code. Construction Stormwater Pollution Prevention Plan 2 Providence Regional Medical Center Everett, North Site, Everett,Washington