34 The Colorado Experiment Station 
The interior, or water-surface of the pipe, is in good condition. 
The inlet and outlet structures are substantially constructed of re¬ 
inforced concrete, to which the pipe is rigidly joined, as shown in 
Fig. 18. For the purpose of minimizing, or entirely overcoming, 
loss of head due to contraction at inlet, the end of the pipe is flared 
at the rate of one inch to the lineal foot until the diameter at the 
Pig - . 22. Siphon No. 6, Arkansas Valley Conduit, Pueblo. 
entrance is increased by one foot over the diameter of the main 
pipe. Wasteways are provided in the channels just above the in¬ 
takes, from which are discharged surplus flood waters collected 
from the hillsides in times of heavy rain. There are no grating 
Fig. 23. Siphon No. 8, Arkansas Valley Conduit, Pueblo. 
screens at either end of the siphon, for the reason that little debris 
of a floating nature is carried by the canal, and in freezing weather 
ice would form over the screen so as to completely block the flow; 
neither are there any blowoffs at the lowest points along the pipe 
Fig. 24. Siphon Nos. 18 and 19, Arkansas Valley Conduit, Pueblo. 
line, it evidently being believed that the velocities of from 2.5 to 
3.5 feet per second on the conduit would effectually prevent the 
deposition of sediment. No information exists as to what extent, 
if any, gravel or particles of shale obstruct the pipe at the bottom 
