caused the disappearance of pools of water following a rain 

 along the rights-of-way. Beneficial from the point of view 

 of the stability of highways, this engineering practice has 

 played its part in hastening the flow of water into the rivers, 

 sometimes incidentally causing increase of run-off and 

 erosion on neighboring farm lands. 



Sufficient data are not at hand to indicate the direct 

 influence of drainage on the store of ground water. In the 

 humid eastern half of the United States the average precipi- 

 tation maintains almost a sufficient store. However, at the 

 breaking point between the humid and arid areas, along a 

 north-south strip in line with the Red River of the North, 

 there has been discovered a considerable drop in the under- 

 ground water table from 10 to 30 feet. This is an area 

 pretty well covered by drainage enterprises. 1 Diminution 

 of groundwater supply is the result generally of greater 

 increase of consumption than of supply, and particularly of 

 the run-off of waters to the rivers before they have time to 

 infiltrate in the words of McGee, "to the cutting-off of the 

 natural source of supply." 2 It is interesting to note that 

 some European countries, older and more experienced than 

 the United States, do not permit drainage into natural water 

 courses of any water that has not served feasible important 

 purposes. 



In some localities ponds and lakes have been lowered or 

 have completely disappeared with the drainage of contigu- 

 ous swampy and other wet lands. 



An influence of drainage on the groundwater storage in 

 some areas appears to be the throwing on it of a heavier load 

 by the pumping of supplies for domestic, agricultural, 

 industrial, and other uses, without corresponding replenish- 

 ment. This appears to have been the influence particularly 

 in the area of the Dakotas, but there are local instances in 

 the more humid east. As ponds, creeks, rivers, and other 

 sources of water have diminished or disappeared, pumping 

 has had to replace the lost source. It should be here noted, 



1 Report of National Resources Board, 1934, p. 309. 



2 W. J. McGee, Wells and Subsoil Water, Bulletin No. 92, Bureau of Soils, U. S. Depart- 

 ment of Agriculture, Mar. 26, 1913, p. 182. 



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