prevent the floods which have
devastated that region from time to time. Water-power amounting to
25,000 horse-power has been developed by the construction. This power
is used in part for pumping, and another area, estimated at 40,000
acres, outside the territory covered by the canals has been reclaimed.
The power is also used for lighting, for manufacturing, and for mining.

It was seen that the Shoshone River, in northwestern Wyoming, during the
season of melting snows, carried away more waste water than would be
adequate to reclaim many thousands of acres in the arid regions of the
lower altitudes. Two million two hundred and fifty thousand dollars were
allotted for the construction of the Shoshone Dam which will form a
reservoir of water sufficient to irrigate 75,000 acres of land 50 miles
farther down the river.

[Illustration]
Shoshone Dam, Wyoming.
Highest dam in the world. Height 328.4 feet.

The Truckee-Carson project provides for the irrigation of 150,000 acres
in western Nevada. The water of the Truckee River, which flows out of
Lake Tahoe, is distributed by canals having an aggregate length of 670
miles. The main canal was opened in 1905.

By the close of the year 1906, over $39,000,000 had been allotted for
works under actual construction, and this amount had increased to
$119,500,000 within four years. It has been estimated that the land thus
reclaimed will alone be worth $240,000,000. The additional cost of a
project is assessed against the land. When the land is sold, the money
received is used for the development of new irrigation areas.

Another significant plan outlined by the irrigation congress in its
meeting, 1911, provided for bringing about the complete reclamation of
all swamp and overflowed land. The swampland area of the United States
exceeds 74,500,000 acres, or an amount greater than the area of the
Philippine Islands by 1,000,000 acres.

The Mississippi basin has been called the heart and soul of the
prosperity of the United States. Two-fifths of the area of the country,
comprising one-half the population, is tributary to the Mississippi
system, which has over 20,000 miles of navigable waters. This valley
produces three-fourths of our foreign exports. The network of railroads
covering this territory has for a number of years furnished altogether
inadequate transportation facilities, and conditions have grown steadily
worse. Traffic experts throughout the United States have been a