446 NEW YORK STATE MUSEUM 



Cubic feet 

 per second 



May 21, 12* m 30,730 



May 21, 6 p. m 26,500 



May 22, 7 a. m 15.650 



May 22,12 m 13,650 



May 22, 6 p. in 10,720 



1 May 23, 7 a. m 7,300 



May 23, 12 m 6,700 



May 23, 6 p. m 5,690 



May 24, 7 a. in 5,390 



The total runoff from 7 a. m. of May IS to 7 a. m. of May 24 was 

 over 7,000,000,000 cubic feet. 



On the morning of May 21 the flats in the broad, level valley of 

 the Genesee river and Canaseraga creek, between Dansville, Mount 

 Morris, and Rochester, which have an area of from 60 to 80 



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MAY 19 



6 AM NOON 6 RM 

 MAY 20 



6AM NCCN 6 -H 



MAY 21 



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 MAY 22 



6AM NOON 6PM 



MAY 23 



6 AM NOON 6 PM 



MAY 24 



Fig. 3o Flood flow of Genesee river May 18-23. 1894. 



square miles, were nearly flooded, in some localities to a depth of 

 from 4 to 6 feet. On account of the large pondage by these flats, 

 although the maximum runoff at Mount Morris was 42,000 cubit- 

 feet per second at 3.30 a. m. on the morning of May 21, at 

 Rochester the maximum flow did not at any time exceed about 

 20,000 cubic feet per second. We have, then, a case where a largo 

 pondage has, by prolonging the time of runoff, modified a flood- 

 flow over 50 per cent. As further illustrating the effect of a large 

 reservoir, or, what is the same thing, the effect of a large pond 



