226 REPORT OF THE COMMISSIONERS OF 



The object sought in each is to retard the flow of water on an enclosed incline 

 plane, chiefly, with "buckets," steps or falls, creating- "pools" of water flowing with 

 moderate velocity through which the fish may swim easily from bottom to top over 

 the obstruction in which the fishway is erected. 



In building a fishway it must be constructed with sufficient strength to resist floods 

 and ice in the breaking up of the stream in spring, and in some instances protected 

 against damage by log drives. 



Properly constructed a fishway adds strength to a dam, instead of weakening it as 

 is sometimes supposed. In locating a fishway the entrance must be so placed that 

 fish can find it easily, and this is best done by making the entrance at the base of the 

 dam as is shown in the illustrations; and the flow of water must be of sufficient 

 volume to attract fish to it and enable them upon entering, to swim through it and at 

 the same time there must be no unnecessary waste of water. As a rule, however, 

 fishways are only used by fish when the stream is in moderate flood and water is 

 wasting over the dam in which the fishway is constructed. 



By entrance to the fishway I mean the down-stream end of it, for I seriously 

 doubt if young or adult fish resort to a fishway in descending a stream unless they 

 chance upon it because of the current which it may create. An enclosed fishway 

 should be constructed to admit light from top and sides, for some species of fish are 

 extremely timid and hesitate to enter a dark fishway. This is particularly true of 

 shad and, in fact, I do not know of shad passing through a fishway in any considerable 

 numbers except in one instance, and even that is disputed ; but the proof seems to 

 me sufficient to establish the fact that shad have passed through fishways in 

 Lackawaxen dam, in the Delaware river. This is a folding dam and is raised only at 

 certain seasons and stages of water, and upon visiting the dam to examine the fish- 

 ways I found a divided opinion concerning their efficiency, some contending that the 

 shad passed up-river before the dam was raised, and others that the shad did not pass 

 after the dam was erected until the fishways were constructed. 



Seventy-five miles further up-stream, I found, upon questioning disinterested wit- 

 nesses, that shad did not run to that point after the construction of the dam, as they 

 did formerly, until the fishways were built, when the shad run was resumed as in the 

 years before the dam was erected.* 



* Since the above was written I have met Mr. J. R. Peck, Tax Agent of the Delaware and Hudson 

 Company, who told me that he had seen a solid mass of shad in the Lackawaxen fishways on the 

 Pennsylvania side of the river during the shad run, the shad passing through as rapidly as the 

 crowding of a great number of fish at the entrance of the fishway would permit. Further, I desire to 

 put on record that Mr. Peck informed me that the shad did not use the fishway on the New York side 

 of the river, but all passed up over the dam on the Pennsylvania side, and his statement was based 

 on personal observation. 



