BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 31. pp. 329-338 June 3o, 1920 



QUANTITATIVE METHODS OF ESTIMATING GEOUND- 

 WATER SUPPLIES ^ 



BY OSCAR E. MEINZER 



{Presented before the Society December 31, 1919) 



CONTENTS 



Page 



Introduction ^29 



Four groups of methods 330 



In general 330 



Intake methods 331 



Discharge methods 332 



Water-table methods 334 



Underflow methods 337 



Conclusion 338 



Introduction" 



The water that comes from beneath the surface of the earth has from 

 time immemorial been regarded by man as a mysterious boon — cold, 

 clear, and presumably pure ; wonderfully refreshing to the hot and weary 

 wayfarer ; essential, perhaps, to the very life of the communit}^, yet with- 

 out cost and generally regarded as inexhaustible ; coming from some dark 

 orifice in the earth, its source unknown and unknowable ; a great blessing 

 freely and mysteriously bestowed on man by some benevolent but capri- 

 cious Providence. When, very rarely, in times of unusual drought, this 

 mysterious blessing, which was regarded to be perennial and inexhaust- 

 ible as the air itself, was cut off and the spring or well went dry, the 

 occurrence was a calamity, in the face of which man stood helpless in 

 fear and awe. 



When at last the geologist appeared, with his methods for beholding 

 what is beneath the earth's surface, concealed from ordinary eyes, some 

 of the mystery of these hidden waters began to disappear, and it became 

 possible to give a rational explanation of their occurrence and origin and 



Manuscript received by tlie Secretary of the Society December 29, 1919. 

 Submitted by permission of the Director of the U. S. Geological Survey. 



(329) 



