192 



ENGINEERING FOR LAND DRAINAGE. 



Seepage Water on Roads, 



It is not uncommon to encounter water veins or 

 <*spouty " places where excavation for road grades is 

 made in grading hills. When these are not provided 

 for, they present one of the most serious obstacles to 

 the maintenance of the road surface. The remedy for 

 this defect may in most cases be easily and effectively 

 applied. Find where the water comes from and inter- 



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\4m 



Fig. 38. — Tile Drain to Intercept Seepage-water. 



cept it by means of a few tile drains before it reaches 

 the base of the road-bed. Lay the drains in the soil 

 where the water is found and extend the outlet line to 

 the nearest available exit. The grade of the lines and 

 workmanship in general should be as carefully looked 

 after as in field drainage. Two hundred feet of 3-inch 

 or 4-inch tile wisely used will frequently abolish a 

 troublesome mud-hole on a hill road. 



Surface Drainage of Hill Roads, 



Roads on hills which have a grade of 3 per cent or 

 more are frequently injured by storm water making a 

 channel in the middle, or in the wheel tracks of the 



