Naches - Selah

The Naches Selah canal diversion (approximately 175 cfs) is located on a left bank of the Naches River about 1/2 mile upstream of the Tieton River confluence in Yakima County, Washington. The current Naches Selah fishscreen facility (improved in 1995) replaces a drum screen that did not meet design criteria for the protection of juvenile and adult anadromous fish during canal diversions.

The facility now consists of six vertical flat plate screen panels, each 6 feet high by 13.5 feet long. The screens are constructed of 0.069-inch (1.75-mm) wedge wire fabric placed with slots oriented vertically. Control baffles installed immediately downstream of these panels allow flows to be regulated to maintain uniform approach velocities.

A mechanical cleaning brush moves back and forth over the length of the screen to keep the screen free of debris.

The bypass entrance channel is a full-depth, 24-inch wide rectangular channel that is 11 feet long. An adjustable weir gate at the end of this channel controls flows that then drop into 4-foot wide by 10-foot long downwell. Bypass flows are then conveyed through a 24-inch diameter PVC pipe for 220 feet to the river.