METHODS OF APPLYING WATER. 



193 



gating ditch, as outlined in Fig. 56. This should be 

 filled in from one to six hours. In the full check 

 water should barely cover the highest portion of the 

 ground, but stand six inches to one foot deep in the 

 lowest portion of the check, according to the contour 

 interval. The contour levee should have its top about 





cdHrw/it '£i'n£' 



ii_"""'"*-<2i^ B i 



i = 



FIG. 56 — CONTOUR OR BORDER SYSTEM. 



half a foot above the water surface of a full check. 

 When the upper check is entirely submerged, gates are 

 opened from the irrigating ditch into the next lower 

 check, those admitting water to the upper check are 

 closed, and one or more gates in the contour levee be- 

 tween the two checks are opened to permit the surplus 

 water from the first to drain into and assist in submerg- 

 ing the second one. This will require less time to fill 

 than the first, because the supply of water from the ditch 



