12 
COLORADO EXPERIMENT STATION. 
fore, of lessening the loss is to change the character of the surface of 
the lake bottom by the deposit of a thin stratum of fine material. 
Since flood waters often contain a large percentage of silt, their use 
and the deposit of such silt, seals the bottom and may make the 
basin nearly water tight. 
The success of the silting process may be expected to be greater 
with small reservoirs than with large ones. Much of the silt is de- 
posited where the speed of the water is checked, or near the inlet. 
Near the outlet, where the seepage is usually the greater, less silt is 
deposited. Yet if the sediment is fine much benefit may be ex- 
pected by application of this process. 
In many cases the water may be made artificially muddy by 
throwing clay into the inflowing stream, taking pains that it is finely 
subdivided and is carried in suspension. 
§ 17. The loss by seepage from sites, for reasons|alreadyimen- 
tioned, may be expected to increase with an increase of depth of 
water in the reservoirs, and to become less with the lapse of time. 
Effect of Depth and of Sediment on Loss of Water from Reservoirs. 
Observations under C. Trautwine, Jr., 1897-98. 
The observations reported were during the winter, with the sur- 
face of the lakes nearly stationary, and do not show the effect of 
variation in depth. Several cases, where the loss has been meas- 
ured from canals, show that the loss increases with the depth of 
water in the canal, but the loss seems to be greater than shown from 
theoretical considerations. From Darcy’s ex|)eriments the writer 
