44 
SEEPAGE OR RETURN WATERS FROM IRRIGATION. 
feet, and in 1895, when the gain was much greater than in previous 
years. The large gain corresponding to March, 1892, is probably 
due to the fact that this measurement was taken immediately fol¬ 
lowing a storm, which had covered the ground with snow, and, 
slowly thawing, had filled the surface of the soil. Such a case as 
has been shown by King, makes its influence felt at once on the 
underground water, even though the intermediate space be dry. 
The return tor 1891 is less than the average amount. There is a 
doubt concerning that gaging. The measurements of the lower 
part of the stream from the Pump house, at Greelev, to the mouth 
of the Poudre, were made by Messrs Hope and Trimble, who con¬ 
tinued down the Platte, while the upper ones were made by other 
parties. Phe results of the low^’er party were taken and compared 
with those of the upper. It is possible that the interval of one day, 
‘or the use of different meters, may have had some effect. 
There is a sensible increase after allowing for the effects of 
temperature. 
RAPIDITY OF FLOW OP SEEPAGE OR UNDERFLOW WATER. 
§ 32. Inquiries for information regarding the movement of 
underground waters is so frequent, that though it was not intended 
to say anything on the subject in this bulletin, it is desirable to give 
a brief statement of the facts as they appear to be. 
Direct evidence of the speed with which water passes through 
any considerable distance underground is almost entirely wanting. 
Attention has been awake to evidence bearing upon the question, 
but in the course of extensive travels over much country for some 
years almost none has been encountered. Cases where lands have 
been seeped subsequent to the construction of a ditch have been 
sought, but most cases have been complicated by other conditions, 
which make the answer anything but conclusive. Subsequent 
experience has also led to the conclusion that the appearance of 
seepage may give very unreliable testimony. For example, on the 
grounds of the Colorado Agricultural College a well was sunk about 
200 feet fiom a canal and about ten feet lower. In the course of 
some measurements on the well, it was found that w^henever w'ater 
was turned in the ditch the w’^ater began to rise in the w'ell within 
twelve hours. There is every reason to doubt that water passed 
that distance in that time. The case is similar to that where water 
is turned in a hose. If the hose is already full of water, water 
immediately begins to run from the lower end. If the hose is 
empty, some time will be required to fill the hose before the water 
begins to run. If already full, the pressure is transmitted in very 
short time, and the increase which is seen very often in the flow of 
seepage when water appears in a neighboring canal may be due to 
the transmitted pressure, rather than to the direct passage of water. 
