U. S. NATIONAL PARK SERVICE 



Figure 6. Beaver dam and pond. On many little 

 waters man-made dams of similar construction are 

 suitable. 



Figure 7. Artesian well. Water flowing through 

 porous strata is forced to the surface by the pressure 

 of a distant underground reservoir at a higher level. 



U. S. BUREAU OF AGRICULTURAL ENGINEERING 



