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WORK OF THE UNITED STATES FOREST SERVICE ial 
uses and for irrigation comes, in many cases, from rain and snow 
falling on the mountains and hills. Here also are the headwaters 
of many of our navigable rivers. Congress, therefore, made the 
preservation of conditions favorable to stream flow one of the prin- 
cipal objects in the establishment and administration of the national 
forests. 
It has been increasingly apparent that upon the condition of the 
watersheds depends the stability of many communities. The rela- 
tionship of watershed protection to floods and electric-power genera- 
F-243245 
FIGURE 7.—The woodland bed of a mountain stream, Wagner Falls, near Munising, Mich. 
tion has been brought into sharper focus by events of recent years 
that have emphasized the importance of a vegetative cover over wide 
areas. 
Permanent operation of power plants depends in large measure 
upon regularity of the water supply and the checking of silting. 
Along the streams within the national forests are many sites suit- 
abie for power development. These are open to occupancy for such 
purpose. The Government does not permit monopolization of 
power, however, in any region or allow power sites to be held on 
national-forest land without prompt development. Where scenic 
or other values outweigh the value of a particular site for power, 
the principle of greatest use to the greatest number operates to pre- 
serve the site for the larger purpose. 
A well-kept forest is the best of natural soil holders and is Nature’s 
great water reservoir. Where there is no vegetation, particularly on 
steep slopes, there is nothing but the friction of the soil to keep water 
