DRAINAGE OF IRRIGATED SHALE LAND. 



35 



deep (PI. VII, fig. 1), illustrates very clearly that a drain improp- 

 erly located may be absolutely worthless, no matter how deep. The 

 project is also interesting owing to the extreme rapidity with which 

 the seepage trouble developed. In the season of 1913 about 4 acres 

 near the center of the tract, upon which a young pear orchard was 



I 100 50 100 200 300 400 



Fig. 9. — Forty-acre tract near Canon City, Colo., showing plan of drainage. 



growing and which was seeded to alfalfa, became so wet that the 

 first crop of hay was harvested with difficulty. By midsummer 

 water had risen to the surface of the ground and was running off 

 through the irrigation furrows and waste ditches, and by late fall 

 many of the pear trees and most of the alfalfa were dead (PL VII, 

 fig. 2). 



