Report U 



Plate II 



^ 



Sec/-/ on rf-3. 



? 



^ 



S. 







Sec//o/7 Crfi. 



Afa^H^hjterfsr 



aBaPB^BBBEgaa aas| 



DIKECTIOXS. 



Slope of fishway should not bo steeper than on a ratio of 1 vertical to 4 horizontal. 



Intake, or up-stream end of iishway, should he amply largo and placed not less than 

 1 foot lower than crest of dam. 



Outlet, should be below low-water level and so located or constructed that fish are 

 naturally led to it when ascending the stream. 



There should be relatively deep water, with an unobstructed flow below the outlet 

 of the fishway. An ample discharge of water should attract the fish to the outlet. 



There should be plenty of light admitted in the fishway, and its construction should 

 be such as to bo readily inspected and cleaned of any debris lodging therein. 



The floor of the compartments should bo laid slightly inclined and the bulkheads 

 somewhat obliquely across the fishway, so that the current of water passing through 

 the compartments can more readily clear tho same of sand, gravel, mud, and rubbish. 



There should be no regulating gates or other devices at the intake which necessitate 

 the services of an attendant. 



The apertures in the bulkheads should increase progressively from the lower to the 

 upper ones, to insure overflow from compartment to compartment. 



The flow of water should be abundant, forming small waterfalls over the bulkheads, 

 so that the fish may either jump from one compartment to the next above or may dart 

 through the apertures in the bulkheads. 



While the flow of water through the apertures may reach a velocity of 10 feet per 

 second, there will be relatively quiet water in the compartments, thus furnishing a 

 resting place for tho ascending'fish. 



To maintain the operation of tho fishway at an average high water tho same as at 

 tho ordinary stage of the stream or river, the uppermost compartment is made some- 

 what longer, and a central bulkhead is inserted having its crest at high- water level. 



The fishway may be constructed of wood or masonry and iron ; it may follow a straight 

 line or be built in angles and curves, as the local conditions may require. 



The size of tho fishway depends principally on the volume of water available, and can 

 be made larger or smaller than that shown on plan. The hydraulic head between two 

 successive compartments must be so chosen as to obtain a enrront velocity through the 

 apertures of not to exceed 10 feet per second. At low-water stage of the stream or river, 

 with the fishway flowing full, there should bo a liberal discharge over the crest of thedam. 



The fishwav should be built very strong and bo well protected against tho destructive 

 effects of freshets, drift ice, etc. 



