NATIONAL RECLAMATION OF ARID LANDS. 477 



for i^ower. It is believed that the power which can be developed 

 from all sources under this system will range from 11,000 to 30,000 

 horsepower. 



The main south-side canal has a total length of 13 miles and a 

 capacity- of 100 second-feet. It is designed with a view to enlarging 

 it at some future time to a cajoacit}^ of 800 second-feet. It is 20 feet 

 wide on the bottom, with side slopes of 2 to 1. In fills which occur at 

 a few places it is 4G feet wide on the bottom, the banks being of the 

 full dimensions required by the enlarged canal. In shallow cuttings 

 a berm is left on the inside so as to admit of enlarging it to a full 

 bottom width of -IC) feet at a minimum expense. This canal will 

 have a capacity of 1 second-foot for each 80 acres of land and will 

 irrigate about 8,000 acres by gravitv. 



The main north side canal is 30 feet wide on the bottom, has side 

 slopes varying from ^ to 1 to 1 to 1. and will carry water to a 

 depth of 10 feet for the first 9,000 feet. It is mostly in solid rock. 

 Xear the end of the rock cut the canal will drop 12 feet, from which 

 point for a distance of 5 miles it will be mostly in earth, with a 

 bottom width of 46 feet, inside slopes 3 to 1, outside slopes 2 to 1, 

 to carry 7.5 feet of water. The banks will be 10 feet high and 8 feet 

 wide on top. 



All of the princii:)al structures in the main canal and branches 

 consist of concrete masonry. The inside slopes of all canals in earth 

 on the north side are 3 to 1, the outside slopes being 2 to 1, the 

 width of the banks on all the j^rincipal canals being not less than 8 

 feet and smaller laterals 6 feet. All the banks will be carried 2 feet 

 above the water surface in the canal. In constructing these canals 

 no runways are allowed on the inside slopes, the material excavated 

 between the banks being hauled up the slope, the tramping of the 

 teams being evenly distributed over all parts of the bank. 



Plans for storage.— k^ the minimum flow of the Snake River is 

 appropriated for other canal systems, an elaborate storage system 

 has been designed to furaiish the supply required for the Minidoka 

 project. For a number of years the Reclamation Service has been 

 making surveys of the several lakes on the headwaters of Snake 

 River with a view of utilizing them for storage purposes. The first 

 of these to be utilized is Jacksons Lake, on the south fork of Snake 

 River, in AVvoming. Work has been begun on a temporary dam in 

 the outlet of the lake to raise the surface of the water 10 or 15 

 feet. This dam will be constructed of log cribs filled with gravel. 

 The reservoir thus formed will have a capacity of from 250,000 to 

 350,000 acre-feet. At some later time a permanent structure having 

 a height of 40 feet will be constructed at this point to raise the lake's 

 surface 30 feet, providing a reservoir having a capacity of from 

 800,000 to 1,000,000 acre-feet. This work is being done by force 



