54 
SEEPAGE OK RETURN WATERS FROM IRRIGATION. 
At the time an estimate based on the flow through the sands 
and the amount which might be expected, had not been made, and 
the results were so much less than had been expected—in some 
cases, in fact, showing an actual loss—that it seemed advisable to 
secure the measurements of another year, to confirm or disprove 
the results, before reporting them. In 1894 the volume of the 
river was so small that the errors in the measurement should be 
small. In 1895 the volume of the river was so great that plans 
had to be changed, and the number of measurements reduced. 
Enough, however, were taken to confirm the essential accuracy of 
those of 1894, and a personal inspection of the channels, with this 
in mind, indicates that at the best the increase from such sources 
must be small. 
§ 52. The number of cases in which there is a loss instead of 
a gain is striking ; and even granting that there is no increase from 
these streams, a loss was not expected. It may be said that the 
second measurement has been taken too near the outlet to catch 
the underground flow. In most cases this is not the case. The 
topographical features—the narrowing of the bluffs or some other 
feature—usually guided the choice of the second point. The map 
and the detailed tables of the 1894 and 1895 measurements will 
give a fair chance to make an independent comparison. In the 
case of the Bijou, the second gaging in 1894 was taken near the 
head of the Platte & Beaver canal but a short ways below the 
Bijou. In 1895 it was taken over a mile lower down the stream, 
and where the bottoms were narrow. A third point of measure¬ 
ment was taken in 1894 at the head of the Platte & Beaver supply 
ditch. Comparing the gain between the point above the Bijou and 
this place, we find a slight gain, but it is still less than the average 
of the river. There is very little irrigated area draining into this 
section, and it is especially little between the first and second points 
of measurement. There is some loss for the whole distance from 
evaporation, but during the time of these measurements it is diffi¬ 
cult to account for a loss of more than one cubic foot per second 
per mile from this cause. It has been suggested that these loses are 
due to the varying depths of the bed of sand under the Platte, and 
the nearness of the bed rock in places. There is evidence that the 
thickness of the layer of sand varies, but definite data is lacking. 
If this be the cause of the loss, it would suggest that the bed of the 
Platte is washed out below the entrances of most of the streams, or 
else is filled with a coarser and more porous sand. The gain due 
to the nearness of the rock in some places should correspond to the 
loss at other places. At the measurement above the Bijou creek, 
there is a reef of rock. It shows for most of the width of the 
stream, and, at any rate, leaves only a small channel of sand. The 
gain, however, while more than in many other places, has not been 
marked enough to give great weight to this cause. 
