CATSKILLS AQUEDUCT CELEBRATION NUMBER (October 12-15,1917) 
BROOKLYN BOTANIC GARDEN 
LEAFLETS 
THE BROOKLYN INSTITUTE OF ARTS AND SCIENCES 
Series V Brooklyn, N. Y., October 10, 1917 Nos. 12 and 13 
FOREST PROBLEMS OF THE ASHOKAN 
WATERSHED 
One of the most important problems in the administration of 
a great city like New York is the water supply. At least three 
things are essential: 1. A continuous and abundant source of 
water; 2. A reservoir of adequate size and elevation whence the 
water can be distributed; 3. The maintenance of the water and 
the watershed in a condition of as perfect sanitation as possible. 
For an adequate supply of water it is necessary, not only to 
have a suitable amount of precipitation, but to insure the conser- 
vation of as much of the rainfall as possible to the run-off drain- 
ing into the reservoir. If the fallen rain evaporates too fast from 
the watershed, the reservoir is inadequately supplied. It is also 
desirable that the drainage into the reservoir be as evenly dis- 
tributed throughout the year as possible, otherwise the water may 
get too low at certain seasons of comparative drought. 
The principal factor in realizing these two needs is the veg- 
etation, and especially the trees of the watershed. The old sup- 
position that trees increase the amount of rainfall has been con- 
clusively shown to be fallacious. It has been shown with equal 
or greater certainty that forests increase the humidity and thus 
decrease the rate of evaporation; and it is also known that the 
run-olf from a forested area is more gradual and more evenly 
distributed through a given period of time than from an area 
devoid of trees. 
For these and other reasons it is highly essential to maintain 
proper forest conditions on the watershed of any municipal water 
supply system. Thus, after the rainfall is assured, and the res- 
ervoir and aqueduct are constructed, there still remains one of the 
most important problems of all, namely, to secure and to maintain 
