Yakima - Tieton

The Yakima Tieton canal diversion (approximately 250 cfs) is located on the right bank of the Tieton River about 7 miles downstream of Tieton Dam near Rimrock, Washington. The current facility (built during the 1996/1997 winter season) replaces a structure that did not meet design criteria for the protection of juvenile and adult anadromous fish.

The facility consists of 12 vertical flat plate screen panels, each 7 feet high by 12 feet long. The panels are constructed of 0.069-inch (1.75-mm) wedge wire fabric with slots oriented vertically. Control baffles are incorporated immediately downstream from the screen panels to regulate flow as needed to maintain uniform approach velocity at the screen.

The bypass entrance channel is a full-depth, 24-inch wide rectangular channel that is 16 feet long. An adjustable weir gate at the end of this channel controls flows that then drop into 3-foot wide by 8-foot long downwell. Bypass flows are then conveyed through a 27-inch diameter PVC pipe for 316 feet to the Tieton River.