Figure 1. --Looking upstream on test f ishway (on right). Mesh 

 barrier in foreground prevented fish from entering 

 section of fishway to the left of partition wall. 



MATERIALS 

 The Test Fishway 



All experiments were conducted in the 

 Fisheries-Engineering Research Laboratory 

 located on the north shore of the Columbia 

 River at Bonneville Dam, approximately 140 

 miles from the river mouth. Fish enter the 

 bypass at an elevation of 47 feet above sea 

 level and leave it at an elevation of 60 

 feet. 



The test fishway used in the 1957 

 experiments is shown in figure 1. This 

 unit included six pools, each 16 feet long 

 (weir center to weir center), 4 feet wide, 

 and 6.3 feet deep. With a 1-foot rise 

 between pools, the slope was 1 on 16. The 

 calculated water volume per pool was 380 

 cubic feet. Head on the weirs, measured 

 4 feet upstream of the weir crest, was 0.8 

 foot. There were no orifices in the weirs. 

 The flat weir crest (8-inch width) which 

 had been used in the 1956 experiments was 

 replaced with a Dalles-type crest (fig. 2), 

 Tests at the Bonneville hydraulic labora- 

 tory £' had previously demonstrated that 

 the Dalles-type crest was superior to the 

 broader, square-crested weir in maintaining 



flow stability. The desired flow pattern 

 which had been established for these tests 

 was plunging, but in the 1956 trials, flows 

 often changed from a plunging to a stream- 

 ing or shooting pattern, resulting in a 

 surface rather than submerged motion within 

 the fishway pool. Observations indicated 

 that fish passage was delayed when a change 

 in flow pattern developed. Installation of 

 the Dalles-type crest provided a controlled, 

 stable flow throughout all recent experi- 

 ments, eliminating the undesirable features 

 of changing hydraulic conditions during 

 experimental periods. The calculated flow 

 in the test fishway was 11.8 c.f.s. 



2/ Theus, Harry P. Memoradum report 1-3, The Dalles 

 fish ladder surge studies, March 30, 1955. Ozalid. 



Figure 2. --Sectional cut of the Dalles-type weir crest. 



Arrow indicates direction of flow. 



