HYDROLOGY OF NEW YORK 



445 



It will be noticed that the area at Main street, the first bridge 

 below the aqueduct, is 941 square feet less than that of the Erie 

 canal aqueduct. 



The commissioners also gave some attention to the causes which 

 made the flood of 1865 greater than that of any previous year, and 

 expressed the opinion that the same causes might produce a still 

 greater flood in the future. 1 



As a chief cause, the commissioners considered that cutting off 

 the forests and clearing up lands were likely to lead to heavier 

 floods from year to year. In view, therefore, of what seemed to 

 the commissioners a constant source of danger, they arrived at 

 the conclusion that a much larger waterway was imperatively 

 necessary through the city of Rochester. 2 



A severe flood also occurred in the upper Genesee at Mount 

 Morris in March, 1893, at which time large quantities of ice were 

 left in the streets of the lower portion of that village. 



Flood in Genesee river of May, 1894. It is very common for the 

 flats in the vicinity of Mount Morris to be inundated, with great 

 destruction of farms and growing crops. The flats between Mount 

 Morris and Rochester were inundated May 20-23, 1894, the damage 

 to growing crops at that time amounting to many thousand dol- 

 lars. As interesting data we may discuss that flood, at which 

 time the approximate discharge of the stream at Mount Morris 

 (catchment, 1070' square miles), was as follows: 



Cubic feet 

 per second 



May 18, 7 a. m . GOO 



May 18, 6 p, m 3,090 



May 19, 7 a. m 5,530 



May 19, 6 p. m 5,090 



May 20, 7 a. m 16,580 



May 20, 12 m 22,210 



May 20, 6 p. m 28,000 



May 21, 3.30 a. m 42,000 



May 21, 7 a. m 33,000 



1 The report of the commissioners appointed to investigate the causes of 

 the inundation of the city of Rochester in March, 1865, may be found in 

 Assembly Document No. 117 of the Session of 1866. 



2 The waterway is still substantially the same as in 1865. If anything, 

 it has been somewhat contracted by various constructions since that day. 



