First among the imposing structures of the Service in the order
of beginning and completion is the Roosevelt Dam, the important
engineering feature of the Salt River project in Arizona. Brilliant
and daring in its conception, diverse and complicated in its problems,
and stupendous in its structural features, the Roosevelt Dam stands
today an enduring monument to the creative genius of its designer
and builder. The layman will not appreciate the complexity of the
problems and the variety of obstacles that were encountered without an
understanding of the locality in which the work was carried on. The dam
is located in a region which was once regarded as almost inaccessible
except to the nomadic Apache, who found a safe refuge here for many
years. The nearest railway is 62 miles away. Twenty miles of this
distance is across a waterless, parched and forbidding desert. For more
than 40 miles the country, gashed and fissured into fantastic forms,
a region of stupendous canyons, steep sided mountains, and turbulent
streams, presented an almost insuperable barrier to ingress. It is
a region of colorful and inspiring scenery, but most unpromising as
a site for a large engineering work. The initial step was to build
a highway to the dam-site, a task of much difficulty on account of
the rough country and the unwillingness of white laborers to do the
work. The road was finally completed, largely by utilizing the Apache
Indians, many of whom were remnants of Geronimo’s band of marauders.
The influence of this experiment in employing Indians has been of
lasting benefit to the Red Men of the Southwest, many of whom have
continued on similar work for railroads and other corporations. The
Roosevelt Road, now familiarly known as the Apache trail, is one of the
most spectacular highways in the country, and thousands of tourists go
over it each year in automobiles.
The site for the dam was located at the entrance of the profound canyon
that Salt River has cut through the mountains. Just above the canyon,
Salt River and Tonto Creek converge in a broad, level valley, which is
now submerged to a depth of nearly 200 feet, forming one of the largest
artificial lakes in the country.
The Roosevelt Dam is of sandstone hewn from the walls of the canyon
in which it is built. It is of gravity section, arched up stream, 280
feet high, 168 feet thick at base, and 1,080 feet long on top. At its
base it covers an acre of ground. A building 209 feet square and 26
stories high would about cover the space of the dam except that halfway
up the sides there would be space for two more structures, each 11
stories high and 885 feet long on top. Owing to the long haul for the
railroad the activities of the engineers were varied and numerous.
The Government cement mill turned out 600,000 barrels of first-class
cement, the saw-mill in the National Forest manufactured all the
lumber required to house 2,000 people, and for stores, offices, etc.;
a hydro-electric plant furnished power to the contractor on the dam
and light for the camp; two farms were operated to supply food for the
employés; water works and sewerage systems were installed, and law and
order were preserved during four years of construction. The engineer
had charge also of a large commissary, a big mess, and superintended a
brickyard and cement pipe plant.
During the building of the dam the valley below was the scene of
unprecedented activity. A million-dollar diversion dam was constructed
across the Salt River to divert the stored water into thousands of
miles of canals; power plants, pumping plants, transmission lines,
and a thousand and one engineering details were completed in advance
of the great day when the turbulent floods of Salt River would be
conserved and led to the thirsty lands. On March 18, 1911, former
President Roosevelt, in the presence of an assemblage of nearly 1,000
people, formally dedicated the structure which fittingly bears his
name. By the simple pressure of an electric button the enormous gates
weighing 60,000 pounds were raised and released the pent-up floods
for irrigating nearly 200,000 acres of Salt River Valley. The swift
passing of years has been marked by marvelous progress in this desert
valley. In 1902, when the work was started, the assessed valuation of
the country, of which the valley is the larger part, was $5,000,000. In
1916, the taxable property values were $72,000,000. In 1913, the first
crop census of the project was taken and showed an irrigated acreage of
159,170, and a gross value of crops of $4,775,000. In 1917, the total
acreage watered was 201,600; the gross value of crops was $13,692,000.
During the same period the number of farms increased from 3,600 to
4,326. The net cost of the entire project to June 30, 1917, including
$3,500,000 for the Roosevelt Dam, was $11,367,000. The annual returns
from the land irrigated by it are more than $3,000,000 in excess of
this amount. The gross value of crops in 1917 was almost equal to
that of New Hampshire and Rhode Island in the census year of 1909.
In October of 1917 the Roosevelt Dam, canal system, and power plants
were formally transferred to the Water Users’ Association, under whose
management the project henceforth will be operated.
WRITTEN ESPECIALLY FOR THE MENTOR BY C. J. BLANCHARD
ILLUSTRATION FOR THE MENTOR, VOL. 6, No. 17, SERIAL No. 165
COPYRIGHT, 1918, BY THE MENTOR ASSOCIATION, INC.
[Illustration: ARROWROCK DAM, IDAHO--THE HIGHEST DAM IN THE WORLD]
_RECLAIMING THE DESERT_
_The Highest Dam in the World_