The Columbia Screens are located in the Columbia Canal on the right bank of the Horn Rapids Diversion Dam at river mile 18.0 on the Yakima River (Figure 1). The facility consists of 10 rotary drum screens (8 ft in diameter, 10 ft in length) and a fish return. The water depth in the screen forebay is about 4.2 ft when the canal is at the maximum flow of 150 cubic feet per second (cfs). Flow through the fish return is maintained at about 25 cfs by placing dam boards in the fish return.
Figure 1. Columbia Screens