Upper WIP

The Upper WIP canal diversion (approximately 40 cfs) is located on the right bank of Ahtanum Creek about 12 miles southwest of Yakima, Washington within the Yakima Indian Reservation. The screens are located on the canal, about 70 feet downstream from the diversion. There was no screening facility at the site prior to construction of the current facility in 1996 and 1997.

The facility consists of four rotary drum screens, each 4 feet in diameter and 12 feet long. The screens are constructed of 4.5-12 stainless steel woven wire mesh. This provides clear openings of 0.117 inch and a net open area of 20 percent.

The bypass entrance channel is a full-depth, 18-inch wide rectangular channel. An adjustable weir gate at the end of this channel controls flows that then drop into a 3-foot wide by 9-foot long downwell. Bypass flows are then conveyed through a 21-inch diameter PVC pipe for 475 feet to Ahtanum Creek.