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POINTS FOR PRACTICAL IRRIGATORS 



SAND IN IRRIGATING DITCHES. 



A correspondent writes for some infor- 

 mation upon the best method of prevent- 

 ing a main irrigating ditch from being 

 filled up with the sand and silt that is 

 present in nearly all the streams to a 

 greater or less extent, especially during 

 the winter season. 



There are two ways of doing this: By 

 watching the flow of any stream it will be 

 seen that the greater portion of the sand, 

 and that which will cause the most dam- 

 age if allowed to get into the ditch, is 

 carried at the bottom of the stream in a 

 mass which moves with less rapidity than 

 the water over it. To prevent this mov- 

 ing mass from entering the head of the 

 ditch the headgate should be arranged so 

 that the bottom boards are considerably 

 higher than the bottom of the stream. 

 Planking should be put in perpendicularly 

 across the gate, against which the sand 

 flow will strike. Of course if there is no 

 outlet the sand will quickly accumulate so 

 as to clog the gate. To obviate this diffi- 

 culty, at one side of the gate put in a 

 waste weir having its base lower than the 

 base of the headgate. Then arrange the 

 gate in the weir at a height just sufficient 

 to allow the sand to be carried away and 

 not permit more water to escape than is 

 necessary to carry the sand. 



Of course it will be necessary to give 

 the waste weir plenty of fall before its 

 discharge,else it too will clog up. When an 

 unusual amount of sand is carried into 

 the stream by reason of a storm it is desir- 

 able to shut down the headgate entirely 

 until the most of the sand flow is over. 

 But this cannot always be done. 



Another way to keep a ditch clear that 

 has a good fall is to put in waste weirs 

 and gates at regular intervals. Then if 

 the ditch begins to clog up, shut down 

 the first gate, open the weir and let the 

 current scour out the ditch. When the 

 first section is cleaned, open the gate and 

 close the next one, and so on until the 

 ditch is all worked out. This plan is in 

 use in Arizona and proved very effective. 



But 'the best way is, if possible, to pre- 

 vent the sand from accumulating in the 

 ditch, and this can be largely done by the 

 method outlined. 



MACHINERY FOR IRRIGATING AND DRAINAGE 

 CANAL. 



The accompanying cut illustrates a 

 1 1-4 Ditching Dredge manufactured by 

 the Marion Steam Shovel Company of 

 Marion, O. This company makes a 

 specialty of Dredges, Ditchers and Steam 

 Shovels. Their attention is exclusively 

 given to this line. Their plant covers 11^ 

 acres of ground, and is equipped with 

 everything in the way of modern ma- 

 chinery that will cheapen, or better the 

 production. Their power is electricity 

 which is generated in the power house 

 and transmitted to the different depart- 

 ments in each of which is a suitable 

 motor. 



There is an interesting history con- 

 nected with the work on which the Dredge 

 illustrated was used; it was used on the 

 Mesa Canal in Arizona. This canal is 

 part of a system of canals that modern 

 engineers claim was first made by a pre- 

 historic race; they also claim that the 

 system was so nearly perfect in all its 

 details that modern engineers have been 

 able to improve on it only in a few in- 

 stances. When, and by whom it was 



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