416 



GEOLOGY OF THE DENVER BASIN. 



Arkansas, <tt Pueblo, Colo. 



[Drainage area, 4,600 square miles.] 



Discharge. 



Equivalent 

 | depth "ii 

 basin. 



1885. I , , 



Inches. 



M:i\ if. i«,:;i ' 0.27 



June I to 23 .79 



Total | 1.06 



1886. 



January o. 10 



February .12 



March .15 



April .19 



Maj ! .78 



June 1.35 



July .44 



\u u nst .37 



September ' .34 



October .20 



\n\ ember .15 



December .10 



Total 4.29 



Per quare 



mile 



drained. 



See.feei 



0.24 



.69 



.93 



0.09 

 . II 

 . 13 

 .18 

 .66 



1.21 

 .38 

 .32 

 .30 

 .18 

 .13 

 .09 



3.7K 



1 887 



January 



February 



March 



April 



May 



June 



July 



August 



September .. 



i tctober 



November . . . 

 December . . . 



Total . 



Discharge. 



Equivalent 



depth uu 



basin. 



ches. 



0. 10 



.09 



.12 



.15 

 .63 

 .84 

 .si 

 .44 

 . 25 

 .20 

 .15 

 .10 



Persnuare 

 mile 



drained. 



Sec. feet. 



0. 09 

 .09 

 .11 

 .13 

 . 54 

 .75 

 .73 

 .37 

 . 25 

 .18 

 .13 

 .09 



As shown in the above table, the variation in the run-off has been very 

 great, both from year to year and as between the two regions for which the 

 determinations arc made, but a knowledge of the influencing conditions 

 enables one to give an approximate estimate for the Denver area of between 

 I and 5 inches annually; say, for convenience in computing, 4.113 indies. 



EVAPORATION. 



Evaporation plays a most important part in the water economy of the 

 \Ycst, but all attempts at estimating it for land surfaces are the merest 

 guesses. From water surfaces in the Denver area in 1889 it amounted to 

 about 61 inches, based upon the following data. 



