94 



^ w;iio 



□ 



Evaporation station 



SCALE OF FEET 



10 S O 10 20 



Irriqofion 



canal 



FIGUEE 11. --Plan of Isleta station, N. Mex. , 1936. 



Cattails . --Cattails are heavy users of water and should be 

 prevented wherever possible from wasting an inadequate supply. 

 Throughout the arid and semiarid West water is the controlling 

 factor in the maintenance and increase of agriculture and popu- 

 lation. Any waste of a natural resource is to be deplored, 

 Tules and cattails sometimes provide preserves for wildlife, but 

 where they serve no useful purpose they should be eliminated in 

 the interests of water conservation (PI. IV-A) . 



Sedge . --Sedge is likewise a great water user, transpiring 

 nearly as much annually as tules and cattails. The maximum 

 monthly use of water by this species at Isleta was 16.19 acre- 



