37 



ber of canals in southern California. It is well adapted to canals less than 

 8 or 10 feet wide at the top. The method is as follows: 



For a new canal the excavation is made about 6 inches larger on each 

 side than the finished earth section when ready to receive the lining. For 

 an old earth canal all vegetable matter is removed and if necessary more 

 material taken out in tlie same manner as for a new canal. In each case 

 the bottom is brought carefully to grade. To shape the canal ready for the 

 lining, the means used on the canals of Fruitlands Irrigation system near 

 Kamloops were wooden forms 6 feet long. These forms are placed in posi- 

 tion in the xcaavted section as shown in Fig. 27, earth is thrown in be- 

 tween the form and the earth bank and well puddled with plenty of water 

 which was pumped for this purpose. This was found much better and more 

 economical in labor than tamping the earth. Even when using a very wet 

 mud, the ground drains sufficiently to allow the removal of the forms next 

 morning. This leaves a very smooth ditch with moist banks ready to 

 receive the concrete lining (Fig 28). The wooden form is a trapezoidal 

 trough with no bottom; the sides are tongue and groove or shiplap boards 

 nailed to frames made of 2 in. x 4 in. scantlings cross braced for rigidity. 



To place the concrete forms similar to the earth forms are used (Fig. 

 29). This concrete form is smaller than the earth form by the thickness 

 of the lining and is built so as to give a greater thickness of concrete at the 



/,n<J Cana/ w/U 

 concrete form 



fined CanaJ- 



Concrete form 

 for can a/. 



METHOD or co/yctfr- un i no CANALS WITH roK.ns 



HS U3E-D BY FR.UITLAHDS IK.H16ATION AND 



CO.. LTD 

 Fig. 29. 



