IXTRODLCTIO.X 75 



icniuNC'd at frequent intervals, it ul)structs and diminishes the tlow. 

 Ditch cleaning is very expensive. The small Flowing Wells ditch 

 near Tucson, before it was lined, cost $80 per mile annually for 

 cleaning alone. In the Yuma X'alley the cost of cleaning lateral 

 canals by hand is about $550 per mile. Furthermore, gophers per- 

 forate open ditch banks and cause the waste of rivulets tor days or 

 even weeks before the holes are repaired. Sometimes the holes 

 enlarge, and the ditch bank breaks, with consecpient loss of the 

 entire stream. .\ break on the TurUjck canal of Calift)rnia. in 1910, 

 thought to ha\e been due to a go])her hole, caused 1000 feet of the 

 canal an a steep hillsi<le to be washed out, and the canal was out of 

 service for six weeks of the period of maximum need for water; the 

 actual cost of repairs was $20,000, but the damage to crops was 

 estimated at $1,000,000. The maintenance of cement i)ii)e lines is 

 so small as to be negligible. 



Another reason for using cement pipe is that the distribution 

 lines can be run through low ])laces and over ridges; it is not neces- 

 sary to follow grade lines, for tlie water can be carried under 

 pressure through the low ]H)rti<)ns ^^i the line. This makes it pos- 

 sible to square uj) the lields much better and to reduce the cost of 

 grading. ].,ess labor is rccpiired. also, to irrigate from pipe lines 

 than from o])en ditches. 



Again, there is a great saxing of land. ()])en ditches occupy 

 a]:)out one ])ercent o.' the land, but the necessity for turning teams 

 on each side makes the loss three or four percent. An open ditch is 

 a trreat obstruction and interferes with farm operations. With 

 cement pipe the loss of land is ])ractically nothing. 



Si)ecial effort has been made to investigate and report on the 

 various causes of failures of pipe lines. As these causes become 

 fully understood, designers and pipe men will so adjust their prac- 

 tices that the danger of failures will quite disappear. 



.Acknowledgment is hereby made to Messrs. A. L. Enger. F. C. 

 Kelton. H. C. Schwalen, and F. W. Sharman for assistance in con- 

 ducting the various tests of cement pipe, and to Mr. W. E. Code and 

 Miss Hester Hunter for their services in proof-reading. 



