I80 ENGINEERING FOR LAND DRAINAGE. 



becomes the receptacle for valuable manures and gives 

 drainage to the outer parts of the yard. In all cases 

 the surface water from surrounding land should be cut 

 off by shallow trenches supplemented by underdrains. 

 These suggestions, if followed, will result in a great 

 amelioration of the mud evil so often endured by farm- 

 ers and stockmen under the impression that there is 

 no remedy for the knee-deep conditions of their yards. 



Taking Surface Water into Underdrains, 



No surface water should be permitted to enter tile 

 drains direct unless precautions are taken to prevent 

 mud and debris from entering the drain. It is fre- 

 quently desirable to remove surface water by means of 

 underdrains from certain places which are not suscept- 

 ible to drainage by soil filtration nor provided with 

 surface-drain outlets. Some of these are ponds or de- 

 pressions by the roadside, yards which are kept closely 

 compacted by constant use, drainage from carriage 

 washes and barns which is charged with muddy ma- 

 terial, and other like necessities. 



For such purposes the catch-basin shown in Fig. 34 

 will serve an excellent purpose. It is a well con- 

 structed with brick, 3I feet in diameter, with a depth 

 of 2 ftict below the outlet pipe for the settling of mud 

 and heavy material which should be removed when- 

 ever the space below the discharge is filled. The 

 discharge pipe should be not less than 6 inches in di- 

 ameter in any case and should not be connected with 

 any extensive field system, but should extend direct 

 to some large outlet. The inlet should be 10 or 12 



