HYDROLOGY OF NEW YORK 



503 



miles above Ogdensburg September 25, 1900, the discharge was 

 estimated at 614 cubic feet per second (catchment, 1535 square 

 miles), or at the rate of 0.4 cubic foot per second per square mile. 

 There is not enough information about this river to determine 

 whether or not this is the extreme minimum flow, but taking into 

 account the rainfall of 1900, it is probable that the minimum flow 

 is somewhat lower than this. 



Minimum flow of Raquettc river. Only two measurements of 

 the flow of this stream have been made. The first of these was a 

 current meter measurement made at Potsdam, where the catch- 

 ment area has not been determined, by W. C. Johnson, on 

 August 28, 1898, on which day the flow of the stream was Too 

 cubic feet per second. 



A current meter measurement was also made near Massena, 

 October 2-3, 1900, showing the low-water flow of Raquette river to 

 be 934 cubic feet per second (catchment, about 1200 square miles), 

 or at the rate of 0.78 cubic foot per second per square mile. 



There is very large pondage area on the various lakes at the 

 headwaters of this stream, but probably the low-water flow r will 

 go lower than the preceding figures — how much, there is no way 

 of stating at the present time. 



21 in i inn in flow of Hudson river. Measurements of the flow of 

 the Hudson river have been kept at Mechanicville since October, 

 1887, the record of which to November, 1902, inclusive, is presented 

 in tables Xos. GO, 61 and 62. The natural flow of this stream is 

 somewhat obscured by a considerable number of lumbermen's 

 reservoirs on its headwaters, the total storage of which aggregates 

 4.000,000,000 cubic feet, as well as by two reservoirs on Hoosic 

 river in Massachusetts. In 1898-9 Indian lake reservoir was 

 constructed with a storage capacity of about 5,000,000,000 cubic 

 feet. The water stored in Indian lake is usually let out in the 

 months of August, September and October, assisting the low-water 

 flow materially, while the water from the lumbermen's dams is let 

 out in the spring, and tends to increase floods somewhat. 



The month of minimum runoff for the whole period covered by 

 the measurements was August, 1899, the mean for the month being 

 1393 cubic feet per second (catchment, 4500 square miles), or at 

 the rate of 0.31 cubic foot per second per square mile. The flow 

 for one day during this month was 993 cubic feet per second, and 



