LOSSES FROM CANALS BY SEEPAGE. I I 
merits of canals as desired, but a distance of some forty 
miles has been measured, which is sufficient to reveal the 
extent of the losses and some of the conditions. 
The Empire canal is one of the largest canals taken 
from the Rio Grande river. It heads on the south side some 
miles east of Monte Vista. It is cut rather deeply in the 
plain. In the first five miles there is found a gain of six- 
cubic feet per second. 
The Blackmore ditch is a small ditch on the north side 
of the river, heading nearly opposite the town of Monte 
Vista and extending east. It starts above the region that is 
showing sub-irrigation and for a portion of its length its 
channel is a little above the plain. It was found to lose 
nearly four cubic feet per second in two miles. 
The Prairie ditch was measured for some miles from its 
headgate directly east. The change in volume seems to be 
irregular, there being a gain of 1.42 feet in three miles, 
passing across the river bottom, then a loss of 1.80 feet in 
one and one-half miles through a gravelly soil; then as it 
strikes the region that is more or less sub-irrigated, a gain 
of a little over two feet in the first two miles and a gain of a 
little over a foot in the next two miles. The last mile meas- 
ured showed a loss of nearly two cubic feet per second. 
The North P'arm lateral is a branch of the Rio Grande 
canal. The Rio Grande canal takes water from the Rio 
Grande river near Del Norte and with a northeast course 
runs almost at right angles to the river to Saguache, forty- 
five miles northeast. The North Farm lateral passes nearly 
parallel to the river. Its course is through the gravelly soil 
and the excavation extends into the boulder gravel for most 
of the length measured. Mile posts are placed along the 
ditches belonging to the company, so that distances could 
conveniently be told. The first measurement was made at 
the second mile post from the main canal and then at each 
subsequent mile post along the line of the lateral. Two 
measurements were made at different times, on July 6th and 
August 3rd. At the first date the amount of water in the 
lateral was nearly twice as great as at the last date, and the 
loss of water was found to be about twice as much. The 
measurement was carried on until the canal reached the 
border of the sub-irrigated region. 
Laterals iF and iC, which were measured, are branches 
of the same system. 
A measurement was made on the loss of water from the 
Blackmore ditch early in May, in a stretch east of the “Gun- 
barrel road” and included in the measurement otherwise re- 
