342 Irrigation and Drainage 



When in use, it is laid in the furrow with the canvas 

 up stream and the free edge loaded with earth to 

 hold it down, when it effectually holds back the water 

 and throws it out upon the strip to be watered. 



Water is turned into one, two, three or more of 

 these distributing furrows from the head ditch, 

 according to the amount available, and when the 

 lands have become sufficiently wet as far below the 

 canvas dams as the water will readily flow through 

 the grain or grass, these are picked up and moved 

 farther down and the stream again turned out. 

 Water is thus led over successive lands until the 

 whole field has been irrigated easily, rapidly, cheaply 

 and, at the same time, well. 



Where crops are grown in short rotation on a 

 large scale, as they are at Greeley, wheat, alfalfa or 

 clover and potatoes following one another in regular 

 order, it is doubtful if a better or more satisfactory 

 system of irrigation can be devised than the one 

 described. 



If the slopes of the field are steep, and especially 

 if they incline in various directions, then the small 

 grains and grasses may sometimes be irrigated better 

 by the method represented in Fig. 86, where water - 

 furrows are thrown across the surface of the slope 

 nearly along contour lines, giving them only so much 

 fall as is needed to lead the water forward. 



These furrows for grain fields, where they are tem- 

 porary, would be best formed with the ordinary plow, 

 at the time of seeding, and the upturned earth 

 smoothed down, so that it may become set before the 



