HYDROLOGY OP NEW YORK 



33 



fall are such as to insure a large enough runoff of streams to 

 furnish, even under natural conditions, considerable waterpower. 



Artificial modifications. Natural conditions have been largely 

 interfered with by the cutting off of forests and the consequent 

 extensive development of the agricultural interests of the State. 

 Under conditions now existing, the water yield of streams is very 

 different from what it was originally. As a tentative proposi- 

 tion, it may be assumed that the general cutting off of forests in 

 New York has decreased the annual runoff of streams issuing 

 from the deforested areas to a depth of from four to six inches 

 per annum. 



The proof of this proposition is found in considering that in 

 a number of places the runoff of streams is gradually decreasing, 

 not only because of the decrease in forest area, due to clearing up 

 of lands for agricultural purposes, but is even changing because 

 of the varying character of the crops raised from year to year. 

 The fact that such changes are taking place has been very strongly 

 impressed upon the writer in a number of litigations in which 

 he has been at different times employed where the question of 

 damages for diverting water from streams, either for municipal 

 or manufacturing purposes, was the leading issue. Invariably in 

 such cases a large number of old residents have been sworn as 

 witnesses for the plaintiff and have testified that formerly, say, 

 thirty, forty or fifty years ago. as the case may be, the stream 

 in question had a sufficient summer flow to operate a mill of a 

 given capacity. In western New York, where several of these cases 

 have occurred, there are mills from sixty to seventy years old, in 

 which, up to the time of changing from the old-fashioned grind- 

 ing process to the roller process, the machinery was substantially 

 as it was made at the original erection. 



Why icaterpowers are less reliable now than formerly. How- 

 ever valuable water privileges at these mills may have been 

 originally, it is nevertheless certain that now a number of them 

 are practically worthless during several months of the summer 

 and fall of the average year. In order to present a valid reason 

 why the waterpower of streams in western New York may be 



