256 



THE IRRIGATION AGE. 



Payette- Boise Project 



IDAHO. 



An event of far reaching importance and marking 

 the partial consummation of a plan to transform to agri- 

 cultural uses the largest body of sage-brush land em- 

 braced in one project in the United States occurred re- 

 ently in Idaho. 



In the presence of a large number of settlers and 

 residents of the valley the big headgates of the newly 

 constructed government dam in the Boise River were 

 opened and the pent up waters gushed into the broad 

 canal. 



For months the settlers on the south side of the 

 project have been watching with deep interest the prog- 

 ress of work on this structure, for upon its completion 



proper. These tunnels are closed by two 6 by 8 foot 

 cast iron gates, and will be used when need arises for 

 sluicing the silt from the reservoir. The main canal 

 with a capacity of 1,500 second feet, heads at the ex- 

 treme west end of the dam, and the water is taken 

 through eight 5 by 9 foot cast iron controlling gates 

 supported by concrete piers and abutments. 



As the big headgates were opened and the life-giv- 

 ing waters gushed into the canal, the scene was viewed 

 with varying emotions by the throngs gathered there. 

 The engineers gazed with satisfaction at the beautifully 

 finished structure; the farmers saw an abundance of 

 water in their canals, orchards laden with fruit, and 

 enormous yields of grain and alfalfa. But to the states- 

 men came visions of a new Idaho, an Idaho with pos- 

 sibilities unsurpassed by any state in all the golden 

 West. They saw a home on every 40 acres of the 

 project, a rural population of not less than 50,000 peo- 



RESIDENCE ON ROSWELL BENCH 

 - BOISE PROJECT 



rested their hopes of an early and abundant supply of 

 water. The dam is located eight miles southeast of 

 Boise where the river emerges from its canyon. It is 

 of cyclopean concrete founded on compact gravel. The 

 spillway, or dam proper is 216 feet long, 50 feet wide 

 at the base and 51 feet high. Along the down-stream 

 toe of the dam and securely fastened to it is a timber 

 apron. This apron is 50 feet wide and 13 feet deep on 

 the lower side. It is built up of 12x12 timbers bolted 

 together and the spaces between the timbers filled with 

 rock and gravel. At the west end of the spillway is a 

 logway four feet, lower than the spillway crest, and 

 just west of the logway and forming the west abutment 

 of the dam is the fish-ladder. This is of concrete, as 

 are the tunnels, which were built for the purpose of 

 diverting the river during the construction of the dam 



pie, and 50,000 more people living in the cities and 

 towns which have been growing by leaps and bounds 

 since the initiation of the government system gave as- 

 surance of an ample water supply. From conservative 

 estimates of a decade ago on the value of irrigated land 

 and crops it took no complicated calculation to figure 

 out that more than eighteen million dollars worth of 

 taxable property in land values alone will be added to- 

 the wealth of the state upon the completion of the 

 project, and that crops worth not less than six millions 

 of dollars will be grown annually. Already new rail- 

 road lines are being built through the agricultural area, 

 new mines are being opened, and the stock raising in- 

 dustry increased. 



But let us follow the progress of the water taken 

 from the Boise dam. The canal extends for 24 miles 



