The Supply and Uses of Water 203 



The Boise River project (Fig. 61) involves an investment 

 by the federal government of $12,000,000, the dam alone cost- 

 ing about $5,500,000. This money is to be returned to the 

 government by the occupants of the land in twenty annual 



FIG. 61. Arrowrock Dam, Boise River, Idaho, the parapet and lower side 

 of dam. Radius of curve, 662 feet; height, 348.5 feet; length, 1,100 feet. 

 Capacity of dam, 79,800,000,000 gallons. Cost, about $5,500,000. 



installments. A region covering 234,000 acres of desert land 

 will be irrigated. What will be the cost per acre for water 

 rights on the basis of the initial investment ? 



Exercise. Students should obtain information regarding the 

 work of reclamation of desert lands in the United States. Such 

 information should include the geographical features and rainfall of 

 the region, and the size and capacity of dams to meet the require- 



