28 



water on West Gallatin River Avas instituted under some of the repre- 

 sentative canals, and also a study of seepage losses from these canals 

 as atfocting- the duty of watei-. Other studies were also carried on 

 which had a direct bearing on these two phases of the investigations. 

 The studies were confined to three canal systems which were chosen 

 with special regard to their location, and for the reason that the con- 

 ditions encountered under each system varied widely from those of 

 the other systems, the three, however, representing nearh' all the var}^- 

 ing conditions of soil, methods of irrigation, and canal management to 

 be found in the valley of the West Gallatin River. 



The largest canal chosen for the investigation was the High Line 

 canal, belonging to the West Gallatin Irrigation Company. This sys- 

 tem was taken as representative of the larger incorporated canals, 

 which head high up on the river and carry water for several miles 

 before it is distributed to laterals. As a representative of the medium- 

 sized cooperative canal, which conveys its water but a short distance 

 before being used, thus eliminating an}' large seepage losses, the 

 Kughen ditch was chosen. The third ditch was the Weaver and Stone 

 ditch, representative of the small, private or individual ditch, heading 

 on the lower section of the river. 



Before the irrigation season opened recording instruments were 

 installed on each of the canals, and throughout the season a continuous 

 record of the amount of water flowing through each canal was 

 obtained. 



DUTY OF WATER UNDER HIGH LIXE CANAL. 



The register was installed in this canal on the Todd flume, about 2.5 

 miles below the head. At this point the canal crosses a narrow ravine 

 in a flume about 30 feet long by 13.5 feet wide. In the following 

 table is given the monthly flc^w from May 24 to August 31, inclusive, 

 in cubic feet per second, Montana miner's inches, and acre-feet: 



' Discharge of West Gallatin High Line canal, 1902. 



According to the annual report of Mr. E. C. Kinney, superintendent 

 of the West Gallatin Comi)any, there were 2,343 acres of land actualh' 

 irrigated under the High Line canal. The duty given in the following 

 .summary is based on this estimate. 



