Evening star., 1932-11-20
HOOVER DAM TO PROVIDE
NEW LIFE FOR SOUTHWEST
Precious Water Will Be Conserved to
Irrigate 100000 Acres and Will
Remove Danger of Floods.

diversion tunnels was lining them with
an average thickness of 3 feet of con-
crete. The forms to hold the concrete
| in place on the Sides top and bottom
of the tunnel we're designed by the engi-
neers especially for this job. They
were of fabricated steel, and moved
along on track which later became a
part Of the reinforcing of the concrete.
The bottom section was laid first, then
the side sections, and finally the top.
The material for the upper sections was
blown in place by pneumatic concrete
guns feeding into 8-inch steel pipes.
This concrete job afforded the COM
panies cooperating in the Hoover Dam
project an opportunity to try out the
concrete mixing plant being built for
the bigger task of pouring the dam,
and also to test the system by which
gravel is obtained, processed and trans
ported to the site of the work.
The transportation of gravel. or ag-
gregate. was one of the largest prob
lens in the entire project. A total of
27,000,000 tons Is being moved for the
work. To transport the material, 81
bridge over the river have been con-
structed.
River Furnishes Gravel.
The river itself provided the gravel
which the Government engineers have
designated for use in the concrete of
the DAM The deposit, laid down in
prehistoric times by flood waters, is on
the Arizona side, IL miles by road up
stream from the dam site The deposit
is huge-a small desert pocket in itself.
But engineers estimate that practically
all of it will be needed, leaving a hole
r-.1nro fha cay1d farrr,oYlx Low will ho
necessary to hasten the work of loading,
grading and storing the gravel, for the
site of the quarry will be under water
by the time the dam is half completed.
When 1t comes to pouring the con-
crete Of the dam, 45,000000 cubic feet
Of it, a monster concrete plant now
under construction will be brought into
use. The placing of so much concrete
with the speed and economy required
by present-day construction is alone
tremendous task, one which is further
complicated by severe weather con-
ditions.
Consequently it was necessary to de-
sign mixing plant that not only would
exceed all similar plants in size and Ca
Eacity, but also which would have the
most advanced equipment for produc-
ing high-quality concrete continuously
and dependably.
The concrete plants at the site will
be able to produce 10000 cubic yards
Of cement month, working Is hours
daily
The dam was originally scheduled to
be finished in six and half years. The
work has progressed SO rapidly that
this time may be reduced year or
more, making 1t possible to have the
task completed by 1886 or 1887. This
part Of the project will cost approx
mately 100000 900. The remainder
will be spent by the Government for
materials, one item Of which is cement
for the dam. About 10000 freight car
loads will be needed, equal to a train
165 miles long.
The dam and power house, however,
represent only one part of the project.
An engineering feat of almost equal
importance will be the construction of
an irrigation system in the Imperial
Valley OF Southern California. Water
passing over the Hoover Dam will be
allowed. after it has yielded its energy
in the form of electrical power, to fol-
low its age-old course to a point about
Is miles above Yuma, Ariz. There a
long weir dam will be laid across the
channel, resting on the sand of the
river bottom, and the water will be
into canal
Yuma to Get Power.
Opposite Yuma the canal will give
UP about an eighth of its water, which
will be used to yield electrical power
for the city. Afterward it will be
siphoned under its former bed to the
Arizona side, where 1t will irrigate a
forest Of grapefruit trees. The other
seven -eighths will continue through the
canal on the California side for a dis
tance of 20 miles, ending in a network
of capillarieS which will bear life and
bloom for the desert regions around the
Salton Sea.
This canal will be 81 feet wide at
the bottom and 200 feet wide at the
top. 1t will be % feet deep, large
enough to accommodate ships of 10000
tons, with draft of 20 feet. The flow
will be equal to that of the Potomac at
washington and about three-fourths
that OF the Hudson near It's mouth. It
will thus become one of the larger
streams of the Nation.
Still third portion of the project is
that to be constructed independently
by the Southern California Metropoli-
tan Water District an aQueduct 226
miles long, with 155 miles of feeder
lines, from the dam site to Los Angeles.
This link will connect the 114-mile long
lake above the completed Hoover Dam
with the Los Angeles water system and
transport the waters of the once un-
tamable river into the kitchens and onto
the lawns Of persons living hundreds of
miles away.