HYDROLOGY OF NEW YORK 



469 



Serious flood conditions exist in the upper part of the tidal por- 

 tion of the Hudson from Troy to Coxsackie, a distance of about 

 30 miles. The channel is shallow, crooked and narrow and the 

 full effect of floods in the Mohawk and upper Hudson, which come 

 together near the head of the tidal section, are concentrated here. 

 At the ordinary low stage the current is intermittently reyersed 

 by the tide, but upon the occurrence of a flood in the Mohawk and 

 upper Hudson the water rushes into this upper portion of the 

 tidal section until a cross-section, slope, and velocity are acquired 

 sufficient to carry the flood-flow, whatever it may be. 



The flood conditions are greatly intensified in winter and early 

 spring by ice, which forms more solidly in the tidal section than 

 in the steeper tributaries. Whenever a winter flood occurs the 

 breaking up of ice in the upper part of the tidal section, retarded 

 by The field below, continually increases in volume along the 

 crumbling upper edge of the latter, and finally grounds in some 

 shallow or narrow part of this section, creating an ice dam, to 

 which the most disastrous floods of this part of the river are 

 attributable. These dams form at various points in the shallow 

 section — sometimes between Troy and Albany, but usually between 

 Albany and Coxsackie. It is the floods accompanied by these ice 

 dams that have inflicted the most serious damage upon this sec- 

 tion of the river. 



Hudson river floods at Albany. The following from the report 

 of a Committee of the Albany Chamber of Commerce on Freshets 

 in the Hudson River will serve to show the extent of Hudson river 

 floods for twenty-five years : 



Freshets and ice gorges in the Hudson riyer 



Year 



Month 



Eleva- 

 tion 



above 

 M. L. W. 

 1876 



Remarks 



(1) 



(2) 



(3) 



(4) 



1876 

 1877 

 1878 

 1879 

 1880 



1881 

 1882 



Feb. 16 



14.0 



• 



No bad dam formed so far as known. 

 No bad dam formed so far as known. 

 No bad dam formed so far as known. 

 Trains on Susquehanna R. R. could not 



start from depot on account of high 



water. Heavy rainfall ; river rose 11 feet 



in 36 hours. 

 Gorge formed between Stuyvesant and 



lower Kinderhook light. 

 River 12 feet above mean tide. 



March 30 



March 5 





March 27 





Feb. 14. Jan. 2s 





Feb. 12, Mar. 1, 18 

 Feb. 14 







