Arizona republican., 1922-03-16
DAVIS PRESENTS FACTS ABOUT COLORADO RlVEl

upper basin is irrigated. namely
about 100000 acres, OF which about
three -eighths is now under ditch. The
of the upper basin Will
doubtless proceed steadily but ii will
be a long time before the full devel-
opment is reached. and the water
to be consumed by future irrigation
will be available for power at Boulder
canyon until that development is re-
allied. This will greatly increase the
figures shown above for a long tino
to come, and, i'm the meantime, any
regulation of the river above for any
purpose will also tend in increase
them.
The great value OF this power and
the wide demand for it, together with
its magnitude, indicate that the
power privileges OF the Boulder cam
yon reservoir can be made to bear
the entire cost OF the dam.
The markets for power are numer-
Gus and various in this part OF the
country. consisting in general OF the
mining interests in Arizona and Me-
vada, the pumping requirements in
the Colorado River valley and the
needs of the municipalities OF Arizona
and Southern California for munich
pal and commercial uses. Possible
municipal customers of importance
are Prescott san Diego Riverside
and Los Angeles.
A structure necessary to solve tho
problem OF the Colorado river by a
dam in Boulder canyon is so high and
so far beyond the precedents that IL
seems advisable with due care for en-
gineering safety and economy, 10
avoid going outside OF such precc-
"a Il
reason il seems to be desirable to
build the structure Of concrete IN ac-
cordance with well established theory
confirmed by numerous and varied
precedents. A rock-fill structure
might be cheaper but our experience
is so limited that we can not be sure
that this will be the case. and If some
unforeseen difficulties. such as blow
outs under the rock fill, should be
encountered, its expense might even
be greater than that OF a concrete
structure, and we can not be sure thai
Il would be entirely safe.
Comparison Of Boulder Canyon Res
ervoir with Other Possible Sites
The demand for a large regulating
reservoir on the Lower Colorado IS
urgent and imperative, first, for regu-
lating floods; second, for providing
third, for power. Without the power,
the reservoir is not feasible at all. as
the expense would be too great TO be
borne by the other interests alone.
The reservoir site provided by n
dam IN Boulder canyon. or its contir-
uation. Black canyon, is the lowest
point on the Colorado river where a
site or sufficient capacity can be
found. Above this site the Grand
canyon occurs, and no reservoir Of ca
pacity sufficient to control the entire
flow OF the river occurs until we
reach point above the Grand Can
yon National park. A site has been
proposed above the mouth or the
Paria river in Glen canyon, and "
has been urged that a reservoir
formed here would, for given height
of dam provide greater storage ca
pacity, and would so regulate tho
floods as to facilitate the construc-
ton Of other dams farther down.
These are valid arguments, so far as
they so, but such a reservoir would
not answer present purposes for sew
eral reasons. Between the Glen can
yon and Boulder canyon sites about
$4,000 square miles OF drainage flows
into the Colorado, including the Little
Colorado, the Virgin the Paria, the
kanab. and many smaller tributaries.
This region furnishes about 10 per
cent of the water supply passing
Bounder Canyon, and most OF II IS
subject to torrential summer rains.
and TO floods at other times, and the
Glen canyon site would not therefore
give satisfactory control OF the floods.
which is the most urgent OF the prob
lens presented. A satisfactory solu-
ton of this problem could not be ac-
complished at any point above Boul-
der canyon.
ANY large reservoir on the Colorado
must depend for its financial feasihil-
ity upon the availability OF an ade-
quate market for not less than one
half million horsepower OF electric
energy. within economical transmits
sion distance. The principal available
markets are:
!: The Pacific slope OF California.
including the cities OF Los Angeles,
San Diego, Riverside. etc.
?. Irrigation pumping in all direc-
tions.
3. The mining regions OF the
mountains OF Arizona. extending I'm a
broad way from the northweNtern to
the southeastern corner OF the state
and including the cities OF Prescott
Phoenix, and Tucson.
4. The identification OF the South
ern Pacific, the Santa re, and the
salt Lake railways and their
branches,
5. The cities OF Nevada. Utah.
Colorado and New Mexico. and the
mining regions adjacent to them.
All OF the more important markets
above listed are more convenient 10
Boulder canyon than to Glen canyon.
This is especially true OF the most
important market the cities and irri-
cation districts OF southern Califor-
mia. To reach these the most feasible
routes for transmission lines, con
sidering the importance OF transpor-
tation in their construction and main
tenance. is approximately along the
railroad routes. These compare about
as follows. taking Los Angeles as
typical and deducting 20 per cent a.
the distance that might be saved by
cutoffs:
yon to Los Angeles.
Los Angeles to las Vegas, by
Las Vegas to Boulder Canyon, by
ran Y''s...'''.'.::'''.'''.' ~
Total ...4.-.-.. ssss..ss... 80
Less 20 per cent .........s.... %
Net transmission distance .... 299
Transmission Distance Glen Canyon
to Los Angeles
Los Angeles to Flagstaff by rail. 548
Flagstaff to Junction bv rail .. 80
Junction TO Glen Canyon by rail. 130
Total ............,....... 70a
Less 20 per cent .............. lfi
Net transmission distance ,g..... 5sS