HYDROLOGY OP NEW YORK 



491 



On the Allegheny, Susquehanna and Delaware rivers and their 

 tributaries floods may rise to 50 to 60 cubic feet per second per 

 square mile, and on torrential streams generally, throughout the 

 State, they may at times be from 80 to 100 cubic feet per second 

 per square mile. In a few cases on streams of small catchment 

 areas they may rise to 125 cubic feet per second per square mile. 

 The latter flows, however, are not very common. 



Minimum Flow of Streams in New York 



Whatever the purpose for which an inland stream is to be 

 utilized, the first question asked is with regard to the minimum 

 flow. If for power development, the minimum flow will determine 

 the amount of power which can be insured on a given head ; if for 

 the water supply of a town, the minimum flow will indicate at 

 once the number of people which may be supplied without storage. 

 From every point of view, therefore, a knowledge of minimum flow 

 is a matter of the first importance. Below are given the minimum 

 Hows of the inland streams of the State of New York, so far as 

 information is at hand. 



Minimum flow of Niagara river. According to table No. 45, the 

 minimum discharge of Niagara river was in November, 1895, when 

 the flow for the entire month averaged only 177,852 cubic feet per 

 second (catchment above Niagara Falls, 265,100 square miles), or 

 the flow was at the rate of 0.67 cubic foot per second per square 

 mile. 



Minimum flow of west branch of Canada way creek. In the 

 summer of 1883 measurements were made of the west branch of 

 Canadawav creek in Chautauqua county from July 18 to Sep- 

 tember 2 of that year. This stream, which is the source of the 

 water supply of the village of Fredonia, has a catchment area 

 above the point of measurement of 4.3 square miles. The valley 

 is deep cut for a distance of 3 miles from the measuring point to 

 its extreme headwaters. Small springs issue frequently through- 

 out the valley. On July 18, 1883, the stream was flowing at the 

 rate of 541,620 gallons in 24 hours, or 50.2 cubic feet per minute, 

 and very gradually decreased to 270,000 gallons, or 25 cubic feet 

 per minute, on July 22. Rains between July 22 and July 29 

 brought the stream up to a discharge of 1.31.9,000 gallons per day, 

 or 122.1 cubic feet per minute, on the latter date. The flow then 



