CONCRETE LINING FOR IRRIGATION CANALS. 



77 



TURLOCK IRRIGATION DISTRICT, TURLOCK, CAL. 



In 1910 this district made a hydraulic fill inclosing an old unsafe 

 wooden flume on trestles across Peasley Gulch, and in the fall of that 

 year, after the canal was emptied, the wooden flume box was removed 

 and a concrete lining substituted. The lined section is 365 feet long, 

 with a bottom width of 40 feet. The side walls, 4 inches thick and 

 9 feet high, are reinforced with No. 6 wire fabric (6 by 6 inches) and 

 have a batter of £ to 1. Buttresses with the same batter are built 

 at 8-foot intervals back of the lining and similarly reinforced. The 

 floor, which is 6 inches thick and of the same construction as the 

 sides, is concaved, being 1 foot lower at the middle than at the sides. 



Fig. 11.— Concrete-lined canal, Yakima project, U. S. Reclamation Service, North Yakima,Wash. 



Concrete floor ribs 12 inches deep and 8 inches wide are spaced 

 equally with the buttresses and reinforced with two ^-inch steel 

 bars. The lining is made of 1:3:5 concrete placed behind wooden 

 forms and cost $16 per cubic yard. It has no joints and no cracks 

 of importance have developed. 



MODESTO IRRIGATION DISTRICT, MODESTO, CAL. 



Considerable concrete lining has been constructed to date in 

 Modesto main canal, but all of it is for providing increased safety, 

 and the small saving of seepage secured is merely incidental. 



In the narrow canal sections near the headworks the velocities 

 range from 5 to 8 feet per second. Where it has seemed necessary 



