3003 W CASINO RD BLDG 45-12 2016-10-20

STATIC TEST FACILITY PRELIMINARY STORM DRAINAGE REPORT EVERETT,WASHINGTON SECTION 4: FLOW CONTROL AND WATER QUALITY ANALYSIS AND DESIGN Existing Conditions The project area is approximately 6.84 acres and is partially covered by the S4 temporary parking lot and a spoil pile. Currently, the majority of the stormwater enters the existing stormwater system located at the southwest and northwest corners of the project site. A negligible amount of stormwater enters the grass lined drainage ditch between the S4 parking lot and Flightline which discharges into Pond D and the southwest pond,Pond X. The north pond,Pond D,was constructed as a TESC BMP's during the Fightline Expansion,prior to the construction of the S4 parking lot. In 2010,the S4 parking lot was constructed with a catch basin and pipe network that captured all of the surface runoff from the paved surfaces and conveyed to the existing storm drainage system identified in Section 3, as DP#1 and DP#2. A portion of the runoff associated with the Preload/Spoil Pile enters the DP#1 and #2 by runon and conveyance. A portion of runoff from 94'St. SW, 29''Ave.W and the Preload/Spoil Pile enters the jurisdictional ditch network and discharges through the 12"culvert at the north and into Boeing Lake at DP#3. See Exhibit 2:Existing Conditions Exhibit at the end of this Section. See the following table for the existing conditions breakdown TOTAL EXISTING CONDITIONS Total Area=6.84 acres Parking Lot/Asphalt/Sidewalks/Hardscapes 2.54 Vegetated area/vegetated spoil pile 4.30 Table 1:Total Existing Conditions CEI Project#141001 Pg.7