Attack by Drainage 



135 



The outlet or point of discharge of a tile drain 

 must be well above the ground surface or above 

 the body of water onto which it is to discharge its 

 contents. Much solid matter is transported 

 through the pipe, and may in time block the outlet 

 at the point of discharge. This condition might 



"V13 



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Wall at Outlet of Tilo 

 Drain 



Cross Section of Outlet 

 of Tile Drain 



Detail of outlet of a tile drain. 



result in the clogging of a part, or aU of the line. 

 It is well to arrange for periodical inspection of all 

 outlets, especially where the lower end of the tile 

 line has a relatively low grade. 



Branch lines should be connected to the main 

 line by means of Y joints and approach it at an 

 acute angle or on a curve. Water-bearing strata 

 may be deep enough to necessitate the installation 

 of several parallel branch lines placed to prevent 

 seepage water outcrop between the lines of tile. 



