A Study of the Proposed Diamond Creek Reservoir
Creators: name: Cheng, Ching Yun
Publisher: name: California Institute of Technology
Year: 1924
Subjects: subject: Civil Engineering
subject: FOS: Civil engineering
subject: FOS: Civil engineering

description: Politically the Colorado river is an
interstate as well as an
international stream. Physically the basin divides
itself
distinctly into three sections. The upper section from head
waters to the mouth of San Juan comprises about 40 percent of
the total of the basin and affords about 87 percent of the
total runoff, or an average of about 15 000 000 acre feet per
annum. High mountains and cold weather are found in this
section. The middle section from the mouth of San Juan to the
mouth of the Williams comprises about 35 percent of the total
area of the basin and supplies about 7 percent of the annual
runoff. Narrow canyons and mild weather prevail in this
section. The lower third of the basin is composed of mainly
hot arid plains of low altitude. It comprises some 25 percent
of the total area of the basin and furnishes about 6 percent
of the average annual runoff.


The proposed Diamond Creek reservoir is located in the
middle section and is wholly within the boundary of Arizona.
The site is at the mouth of Diamond Creek and is only 16 m.
from Beach Spring, a station on the Santa Fe railroad. It is
solely a power project with a limited storage capacity. The
dam which creats the reservoir is of the gravity type to be
constructed across the river. The walls and foundation are
of granite. For a dam of 290 feet in height, the back water
will be about 25 m. up the river.

The power house will be placed right below the dam
perpendicular to the axis of the river. It is entirely a 
concrete structure. The power installation would consist of
eighteen 37 500 H.P. vertical, variable head turbines, directly
connected to 28 000 kwa. 110 000 v. 3 phase, 60 cycle generators
with necessary switching and auxiliary apparatus. Each unit is
to be fed by a separate penstock wholly embedded into the masonry.

Concerning the power market, the main electric transmission
lines would extend to Prescott, Phoenix, Mesa, Florence etc.
The mining regions of the mountains of Arizona would be the
most adequate market. The demand of power in the above named
places might not be large at present. It will, from the 
observation of the writer, rapidly increase with the wonderful
advancement of all kinds of industrial development.

All these things being comparatively feasible, there is one
difficult problem: that is the silt. At the Diamond Creek dam
site the average annual silt discharge is about 82 650 acre
feet. The geographical conditions, however, will not permit
silt deposites right in the reservoir. So this design will be
made under the assumption given in Section 4.

The silt condition and the change of lower course of the
Colorado are much like those of the Yellow River in China. But
one thing is different. On the Colorado most of the canyon
walls are of granite, while those on the Yellow are of alluvial
loess: so it is very hard, if not impossible, to get a favorable
dam site on the lower part. As a visitor to this country, I
should like to see the full  development of the Colorado: but
how about THE YELLOW!