26 BULLETIN 502, U. S. DEPARTMENT OF AGRICULTURE. 
The wet spot became noticeable in the summer of 1913 and by the 
following summer had increased considerably. There was not much 
alkali present, but the ground was very wet. 
A prominent shale ridge outcrops across the north and east sides 
of this tract. A deep arroyo at one time extended across the tract 
GZ SCALE OF FEET 
SSS SSS SSS eS ee —————E—E———————————eeed 
0 
Gyn 
Height of Ground Surface above Datum 
Fig. 3.—One-acre tract near Canon City, Colo., showing plan of drainage. 
in the bottom of the shallow draw in which the affected area is 
located. This was filled in when the land was leveled. It is be- 
lieved that this had much to do with the development of the seepage, 
for not only was the natural drainage afforded by the arroyo thus 
shut off, but the earth filled in became more dense than the natural 
soil and offered greater resistance to the movement of the ground 
water, A careful subsoil examination indicated that the seepage 
