491 



NEW YORK STATE MUSEUM 



Minimum floiv of Genesee river. The following tabulation gives 

 the mean monthly flows of the Genesee river at Mount Morris and 

 Rochester for several low months of the year 1895. the catchment 

 area above Mount Morris being 1070 square miles and that above 

 Rochester, 2365 square miles : 



Mount Morris Rochester 



, * » , * , 



Cubic feet Cubic feet Inches on Cubic feet Cubic feet 

 per sec- per second the catch- per sec- per second 



Month 



ond 



per square 



men 



t 



ond 



per square 







mi 



He 









mile 



May 



174 



0. 



,163 



0. 



,19 



385 



0, 



,380 



June 



128 



0. 



119 



0. 



13 



283 



0. 



226 



July 



105 



0, 



.099 







.11 



232 







.165 





115 



0. 



.10S 



0. 



.12 



254 







.169 



September 



100 



0. 



,093 



0. 



,10 



221 







.106 



October 



104 



0, 



,097 







.11 



230 







.003 



Comparing the foregoing figures for Mount Morris with those 

 for Rochester for the month of October, 1895, it is seen that the 

 proportion of runoff at Rochester was somewhat less for that 

 month than at Mount Morris, although for the previous months it 

 appears to have been larger. The explanation of this is that there 

 are between Rochester, Mount Morris and Dansville extensive 

 flats aggregating from 60 to 80 square miles. The temporary 

 ground-water storage of these flats acts to sustain a somewhat 

 more equable flow at Rochester than at Mount Morris, above which 

 point there are proportionately smaller areas of flats. There are 

 nevertheless some exceptions to this general proposition, as when, 

 in a long-continued dry time, the flats become exhausted of 

 moisture, and to some extent act like a sponge, taking up water 

 from the river, thereby decreasing, in a measure, the outflow at 

 Rochester. 



In the summer of 1S46 Daniel Marsh made a series of measure- 

 ments in order to determine the low-water flow of that year. As 

 the result of nine measurements made at various times in July and 

 August he placed the minimum flow at Rochester in 1846 at 412 

 cubic feet per second. 1 



At Middlebury Academy, Wyoming county, in the catchment 

 area of Oatka creek, the rainfall for the water year 1845 was, for 



'For these low water gngings of Genesee river in detail, see pp. 182-3. 



