Obstructions to Drains 



455 



OBSTRUCTIONS TO DRAINS 



In all cases where water flows through the drain 

 during any considerable portion of the growing season, 

 care must be taken to avoid the presence of trees 



Fig. 144. Showing roots of European larch removed from a 6-inch tile 

 drain, which they had effectually clogged. 



anywhere within three or four rods of the line of tile, 

 otherwise the roots will find their way into the drain 

 through the joints, and there branch out into a com- 



