UNDERGROUND WATER. 
239 
1 foot in thickness sinks into the ground annually. As the annual net supply to the 
reservoir is certainly much less than the 2,000 gallons a minute assumed above'and 
may be only a small fraction of that quantity, there is evidently no need of supposing 
that the water is supplied from below. Samples of water collected at the bottom of 
the C. K. & X. shaft and from the 1,400-foot level of Stratton’s Independence mine 
were examined by Mr. George Steiger and found to contain little but calcium and 
magnesium sulphates. Though the water at both places spurted from fissures in the 
granite, it lias none of the properties of water that has come up from great depth. 
The underground water is invariably cold, that issuing from the El Paso tunnel in 
April, 1904, having a temperature of 14° C., while the temperature of the air was 16° 
C. Thus the behavior, character, and temperature of the underground water all 
indicate a meteoric origin. It is supplied by the ram and snow that fall upon the 
surface of the district. 
EFFECT OF DRAINAGE ON WATER LEVEL. 
When the underground water was first encountered its surface was more nearly 
level than is usual in a region so accidented as that of Cripple Creek. It is hardly 
probable that the coincidence of water level in the western part of the volcanic area, 
with the elevation of the lowest notches in the granitic rim near Arequa and Ana¬ 
conda, was accidental. It may fairly be concluded that, prior to mining operations,, 
any excess of water over that lost by slow seepage through the walls of the volcanic 
funnel made its escape through these notches to Cripple Creek, and thus determined 
the position of the general surface of permanent ground water. The lack of inequali¬ 
ties in the old water surface more pronounced than those indicated by the recorded 
elevations of “first water” suggests further that the volcanic rocks were sufficiently 
permeable to allow the whole water surface in the volcanic neck to very slowly adjust 
itself, under natural conditions, to these outlets. 
When pumping began, however, this adjustment was soon found to be so slow 
that for practical purposes the underground water is to be regarded as occupying a 
number of separate basins. The different effect of the drainage tunnels in various 
parts of the district suggests the same conclusion. It is certain that the water does 
not flow with equal freedom in all directions and through all rocks of the volcanic 
neck. Some of the inequalities of ground-water surface developed by artificial drain- 
age appear in the accompanying table, which is based on a similar table published by 
Mr. V. G. Hills, 0 supplemented by later data. 
a Eng. and Min. Jour., vol. 76, 1903, p. 117. 
