30 The Colorado Experiment Station 
section had taken place, as shown in Fig. 16. In the 900-foot 
section investigated, the upper 300 feet had a bed composed of 
clayey loam with a few scattering, smooth, waterworn stones 
projecting. The bed of the other part of the section was of clayey 
loam upon which aquatic moss was beginning to grow. This canal 
also had an exceptionally low frictional resistance. The section 
was designed as follows: Bottom width, 11 feet; water depth, 3 
feet; side slopes, 1 to 1. The hydraulic elements used were: 
Wetted area . 
Wetted perimeter 
Hydraulic radius 
Slope . 
Velocity . 
Discharge .... 
(n) .-. 
42.0 sq. ft. 
19.5 ft. 
2-15 
.0005 
. 2.2 ft. per second 
.93.7 sec. ft. 
0.025 
MESA LATERAL, GRAND VALLEY CANAL, GRAND 
JUNCTION. The sections investigated were 550 and 600 feet in 
length and at the time of experiment were carrying close to their 
full capacity. The bottom was smoothly lined with a fine sedi¬ 
ment, while the sides were composed of a rather uneven surface of 
clay loam. Short grass grew on the bank which was submerged 
0.5 feet when the canal was full, as in this experiment. 
WILLCOX CANAL, RIFLE. The portion of this canal ex¬ 
perimented upon was a 400-foot stretch just below the concrete 
siphon under Rifle Creek. The bed consists of fine silt, sand and 
pebbles, with a thin scattering of rounded, waterworn stones about 
6 inches in diameter. This canal was first put into operation in 
Fig. 17. Willcox Canal, Rifle. 
the spring of 1912, and its cross-section is shown in Fig. 17. The 
head carried at the time of the test in September, 1913, was less 
than one-twentieth of the designed capacity of the channel. 
Table 8 gives the results of all the experiments on earth 
channels. 
