TILE COMBINED WITH A SURFACE-RUN 



123 



it is best and less expensive to drain with tile than with open 

 ditches whenever possible. With a few exceptions, an open ditch 

 smaller than six feet deep, three feet wide at the bottom, and fifteen 



Fig. 57. — The two protected outlets to the drainage system on this marsh of 125 acres 



Two steel pipes screened by iron rods. 





ifv^-rw 







sm'^ 





Fig. 58. — An open ditch should be deep enough to permit tile to empty into it. With 

 few exceptions, an open ditch smaller than six feet deep, three feet wide at the bottom, and 

 fifteen feet wide at the top, has no excuse for an existence. (Wisconsin Station.) 



feet wide at the top, has no excuse for an existence ; large tile 

 should be used instead, or a surface-run combined with tile will 

 work best. 



Tile Combined With a Surface-Run. — In constructing this 



