Notes
Letter dated July 25, 2000 from Keith R. Smith, Water Resources Manager at Port Of Seattle, to Tom Luster at the Washington Department of Ecology (Shorelands & Environmental Assistance Program), transmitting the Des Moines Creek Flow Augmentation Facility Implementation Plan. The plan describes a facility to increase instream flow to 1.0 cfs and decrease water temperature to 16 degrees Celsius during summer low flow periods. Preferred water source is a Port-owned well near South 200th Street with a water right certificate for 400 gallons per minute (0.88 cfs); application to change the water right was filed with Ecology in June 2000. System components include an eight-inch PVC pipeline conveying water approximately 800 feet north to the confluence of the east and west branches of Des Moines Creek, a manhole stilling basin, riprap quarry spall aeration channel, and a monitoring station with flow and temperature sensors at an existing weir 375 feet downstream. A 4-20 ma variable speed pump control system would maintain target flow and temperature. Backup water source is the Port’s distribution system (Seattle Public Utilities, Highline Water District, King County Water District 125), requiring dechlorination. Based on the report ‘Des Moines Creek Flow Augmentation Plan’ by Paramterix Inc., August 1998. Copies to Elizabeth Leavitt (Port Of Seattle) and David Masters (King County). Administrative Record numbers AR 023777–AR 023779.