FLOATING LOG BOOM 

 TO DIVERT DEBRIS 



FISH-TIGHT SCREEN 



DRUM SCREENS 



WATER BYPASS 

 CHANNEL 



FISH-TIGHT SCREEN 

 DRUM SCREENS 



FISH BYPASS 

 (UNDERGROUND) 



INCLINED SCREEN TRAP 



FiouEE 1. — Diagrammatic sketch of experimental site. 



wide, and 14.5 km. long ; it normally carries a flow 

 of 28.3 to 34.0 c.m.s. (cubic meters per second) . The 

 banks have a 60° slope. The bottom consists pri- 

 marily of sand and silt with some areas of small 

 gravel. The water velocity is relatively uniform 

 because large obstructions are lacking. 



The entrance to the canal is not screened; juve- 

 nile fish migrating down the Yakima River have 

 easy access, especially during periods of low water 

 when a large portion of the river is diverted into 

 the canal. To salvage these fish, the Bureau of 

 Sport Fisheries and Wildlife operates rotary drum 

 screens and a fish bypass system about 1.6 km. 

 downstream from the canal intake. The experi- 



mental site consisted of a 439-m. section of the 

 canal just upstream from the drum screens. 



VELOCITY CONTROL STRUCTURES 



Stoplogs, shunting panels, and screens were 

 manipulated to efi'ectuate and maintain the desired 

 water velocities (0.2, 0.5, and 0.8 m.p.s.). Figure 

 2 is an aerial photo of the velocity control struc- 

 tures. A trash boom at the upstream end of the 

 experimental site diverted floating debris to 

 the bank where it was collected for disposal. Just 

 downstream from the boom, flows could be di- 

 verted to the water-bypass channel (B, fig. 2), 



308 



U.S. FISH AND WILDLIFE SERVICE 



