LOSSES FROM CANALS BY SEEPAGE. 
2 
King’s River and Fresno. 
FVesno Laterals 
Kern county canals 
Kern county, sandy soils. . 
Kern county, sandy loam . , 
Campine, Belgium, sandy 
Erie Canal 
Carpentras Canal, France 
Marseilles Canal 
6 to 1. 70 
1.2 to 6.40 
39 to 2.60 
. . I. to 2. 1.60 
.39101.3 0.87 
2 to 10.00 
.25 to .80 0.60 
1.20 
0.40 
< ( 
i i 
GAINS FOUND IN CANALS. 
In many cases the canals serve as drainage ditches and 
are found to gain in volume instead of loss. Several ex- 
amples may be noticed in the tables, as the Empire canal, 
the North F'arm lateral for a portion of its length, the Prai- 
rie Ditch, the Pleasant Valley and Lake canal, etc. It is 
frequently noticed that some canals have water even when 
their supply from the river is shut off. This is often found 
to be true with the ditches in river bottoms, originally built 
to take water from the river, but which, with the irrigation 
of the upper lands, have now become practically drainage 
ditches. Every old irrigated valley in the state has such in- 
stances. 
In the case of the Hottel mill race at Fort Collins, not 
elsewhere mentioned, which was measured in the fall of 
1897, 3 - gain of over 4 sec. ft. was found in a distance of two 
miles. 
The gains are manifestly more likely to be found in 
deep canals than in the shallow laterals. 
N'AKIATION CE LOSS WITH DEPTH. 
The amount of seepage increases with the depth of 
water in the channel. This is principally from theoretical 
considerations, but has observational confirmation. The 
exact relation must depend on the relative losses through 
the banks and through the bottom or on the relative width 
and depth of the channel. As the soil is rarely uniform for 
any considerable distance, the results from theoretical con- 
siderations can only be a guide as to what to expect. When 
the loss is solely through the banks there is reason for think- 
ing it may vary nearly as the cube root of the square of the 
depth, that is, on doubling the depth, the loss would be 
nearly three times as much; on quadrupling the depth the 
loss would be nearly eight times as much. 
Some interesting observations by J. C. Trautvvine, Jr., 
Chief of the Bureau of Water of Philadelphia, are given in 
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