HYDROLOGY OF NEW YORK 



253 



power development upon them, but which are not specifically 

 mentioned here. 



Below Troy the tributaries of the Hudson river are mostly small 

 and generally not of very great importance, although some of them 

 have considerable power development. One of them, Croton river, 

 is the principal source of water supply of the City of New York. 

 On this part of the river, the catchment basin is rather narrow, 

 and many of the streams issuing from the highlands at either side 

 have such small catchment areas as to carry only moderate quan- 

 tities of water. 



Tides in Hudson river. The following are the elevations of mean 

 tide, mean low tide and mean high tide above mean sea level at 

 New York, and the mean rise and fall of tides at various points 

 along the tidal estuary between New York bay and the Troy dam : 



Locality 



Mean 

 tide 



Mean 

 low tide 



Mean 

 high tide 



Mean rise 

 and faU 













4.70 





.... 0.00 



2, 



,20 



2.20 



4.40 



Dobbs Ferrv 



0.18 



1. 



,62 



1.98 



3.60 





.... 1.68 



0. 



,17 



3.53 



3.70 





.... 1.73 



0, 



.02 



3.44 



3.42 





... 1.88 



0. 



,44 



3.31 



2.87 





.... 2.09 



0, 



,82 



3.35 



2.53 





.... 2.13 



0, 



,82 



3.29 



2.33 





.... 2.43 



1. 



,27 



3.59 



2.32 





.... 2.78 



1. 



,81 



3.75 



1.94 



Trov dam 



.... 3.77 



3. 



37 



4.17 



0.80 



The following gives the hight above tidewater at New York of 

 a number of points on the Hudson river : 



Feet 



New York (at mouth) 0.0 



Troy 3.8 



Saratoga dam (crest) 102.0 



Fort Edward (below dam) 118.0 



Glens Falls (crest of feeder dam) 284.0 



