558 



FORESTRY AND IRRIGATION 



December 



The shortest canal line that would 

 divert the waters of the Little Mis- 

 souri River into the Cannon Ball or 

 Grand River drainage would be a 

 length of more than 170 miles. 



Ever since the enactment of the irri- 

 gation law the citizens of Helena, 

 Mont., and in Prickly Pear Valley 

 have been endeavoring to secure gov- 

 ernment aid in constructing an irriga- 

 tion project to reclaim a large body of 

 arable land. This matter has been one 

 of special importance to the city, in- 

 asmuch as the growth of Helena has^ 

 made the question of water supply a 

 paramount one. 



The irrigation of perhaps 100,000 

 acres lying right at the door of the 

 city would add greatly to Helena's 

 population and augment the business 

 of her merchants and manufacturers 

 immeasurably. Consequently a strong 

 appeal has been made to the Reclama- 

 tion Service to institute an investiga- 

 tion of the feasibility of an irrigation 

 project in that locality. 



One feature of the proposed project 

 which has deterred the Government 

 from proceeding actively in this mat- 

 ter is the fact that all the areas to be 

 irrigated are in private ownership in 

 large tracts, making the proposition 

 more properly one for private capital 

 to exploit. The question of water sup- 

 ply was known to be involved by rea- 

 son of power developments, several 

 companies having appropriated a large 

 proportion of the normal supply. So 

 many inviting projects were known 

 to exist in the state, all of which were 

 free from the complications which sur- 

 rounded the Prickly Pear scheme, that 

 an investigation of the latter was held 

 in abeyance until others more attrac- 

 tive had been made. 



In conformity with a promise by 

 Chief Engineer Newell during his visit 

 at Helena last summer, District Engi- 

 neer Robbins was directed to detail an 

 engineer to make a quick reconnais- 

 sance of the valley and submit a re- 

 port. Mr. Robbins appointed Assist- 

 ant Engineer Prendergast, and he has 

 just concluded an investigation of the 

 project. 



Summarized, the report indicates 

 that while the project is within the 

 limits of practicability, it is not a high- 

 ly favorable one, not being compara- 

 ble with any one of the several other 

 projects in the state which have been 

 receiving the attention of the Govern- 

 ment engineers. 



As a source of water supply, Mr. 

 Prendergast found the North Boulder 

 Creek entirely inadequate, and the val- 

 ley of the stream apparently contains 

 no suitable storage site. One alter- 

 native of bringing water from the 

 upper Jefferson is not deemed as feas- 

 ible as utilizing the Madison River, 

 for the reason that the canal lines 

 would necessarily be of greater length 

 and the country traversed much 

 rougher and containing less irrigable 

 land. Consideration was also given to 

 a proposition to pump water from the 

 Missouri River below the power house 

 at Canyon Ferry, but the cost of power 

 as quoted by the company was so great 

 as to make this plan impracticable. 



Another alternative is to develop 

 power by damning the Missouri River 

 and pumping water from that stream 

 to irrigate lands farther down. The 

 scheme involves many engineering 

 questions, which must be considered 

 before definite statements can be made 

 as to its feasibility. 



The Madison River project em- 

 braces 100,000 acres, one-half of which 

 lies in Prickly Pear Valley, the re- 

 mainder being scattered along the line 

 between the Madison and Raders- 

 burg. This scheme involves the ex- 

 cavation of 131 miles of canals ; a short 

 tunnel, steel bridge across the river, 

 and a masonry weir 300 feet long and 

 10 feet high, also an inverted siphon 

 one-half mile long. The estimated cost 

 is $2,400,000. The canal will require 

 1,000 second-feet of water during the 

 four irrigating months, and the di- 

 version of this quantity would prob- 

 ably effect the flow of the Missouri. at 

 the power site and would result in liti- 

 gation. It is probable that during 

 the coming season the engineers will 

 renew this investigation. 



