An£> theIr relation to Irrigation. 
21 
Carrico; twelve feet in the shallow wells south of Ala¬ 
mosa, and in the deepest wells at Alamosa, fifty-six feet. 
The amount of water to he obtained depends upon 
the character of the strata as well as upon the pressure. 
If water passes through a stratum with difficulty, there 
may be wells of high pressure but small flow, and as 
there is a limit to the rapidity with which water can pass 
even through sand, the flow is not necessarily in propor¬ 
tion to the size of the pipe. The flow frequently increases 
for a time after the well is sunk, due to the formation of a 
pocket or small reservoir ot the bottom, which, by increas¬ 
ing the area of the supplying surface, renders a greater 
flow possible with the same pressure. In general, the 
deeper wells have the greater flow, because of the greater 
pressure. 
The small wells, which are generally of two-inch 
bore, flow from five to twenty-five gallons per minute, the 
latter being considered a good flow, and the cost for the 
same wells is from $25 to $75. The two deepest and 
largest wells in the valley are at Alamosa. One, the town 
well, which flows into a small reservior perhaps forty feet 
square, was measured by passing the water over a rectan¬ 
gular weir. The weir was placed in an opening in the 
bank and left for some time, until the water seemed to be 
neither rising nor falling in the reservoir, when the meas¬ 
urement was taken. The weir was 24 5-16 inches long 
and the depth flowing over, measured several feet from 
the weir, was 3 1-12 inches. Allowing a small correction for 
velocity of approach, this corresponds to a flow of 400 
gallons per minute, or nearly one cubic foot per second. 
Not far from the town well is that of Conrad Bucher, 
which was sunk in the summer of 1889, for oil. This was 
the first deep well sunk in the valley, and has the largest 
flow. It is nearly 1,000 feet deep, but secures the heavy 
flow from 932. It has a double casing, the outer one ex- 
