354 WATER MAKES A GARDEN OF THE DESERT 



Ditches have been built, pipes have been laid, and water has 

 been diverted from the rivers to remote ranches and farms (Fig. 

 221). 



When arid lands were artificially watered, they proved won- 

 derfully fertile and yielded large crops, and many settlers were 



attracted to them. As 

 more and more people 

 settled on the lands and 

 sought to make their liv- 

 ing from them, the prob- 

 lem of irrigation became 

 more difficult. To obtain 

 water sufficient for all, it 

 was necessary to tap dis- 

 tant rivers and to build 

 huge canals. Sometimes 

 mountains intervened be- 

 tween the arid region and 



FIG. 



221. Irrigation canal into which water 

 is diverted for distant ranches. 



the rivers, and canais had 

 to be cut through solid 

 rock. At other points trestles had to be built across chasms 

 as supports for huge pipes or flumes through which water was 

 conveyed. 



" Soon, the miracle wrought when water was supplied to the 

 sun-baked land the fields of splendid grain and the gardens 

 of fruit that replaced the barren region spurred men on 

 to even greater tasks of engineering." It was determined to 

 utilize the tremendous amount of water wasted during the 

 early spring thaws. At the approach of mild spring weather* 

 snow melts rapidly and flows down the mountains faster 

 than neighboring streams can carry it away. The streams 

 overflow their banks, flood the country, and bring destruction. 

 Engineers proposed to store in reservoirs and dams (Fig. 222) 



