IRRIGATION

941

IRRIGATION

gives free land under the homestead laws and permanent irrigation systems and water at cost, although the title to the sources of supply remains in the government until otherwise provided by Congress. When the payments are made for the major portion of the lands irrigated, the control of the works passes to the owners of the land, to be maintained at their expense under such form of organization and under such rules and regulations as may be acceptable to the Secretary of the Interior. Under this act much work is being accomplished and stupendous schemes undertaken. Extensive engineering projects are under way in several of the states and territories affected by this act, which applies to Arizona California, Colorado, Idaho, Kansas, Montana. Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Utah, Washington and Wyoming. The projects already authorized contemplate the ultimate redemption of 2,000,000 acres. Nearly all are capable of extension, so as to redeem many more thousands of acres, and engineers estimate that under The act it will be possible and practicable to reclaim 100 millions of acres of land now almost [or quite useless. The law encourages work along various lines that may develop useful results, and in western Kansas, for instance, that taken up has been to ascertain facts as to the underflow and its utilization foi agriculture by means of wells and pumping.

In June, 1905, the first of the completed works constructed under the reclamation act — the Truckee-Carson in northern Nevada — was formally opened, and the water turned into the great diversion canal for its journey to the thirsty lands. The initial system is used to distribute water over about 30,000 acres, but it is expected the work will be extended to cover 150,000 acres. In March, 1907, one or more projects were under way in each of the 16 states and territories mentioned, and on 14 of these the work had reached such stages that it was expected water would be supplied to a portion of tne lands contiguous to them, amounting to nearly 400,000 acres, within the year. Operations under the reclamation act have stimulated development in western America in many lines. Private enterprise is already engaged upon similar irrigation work, and new railroad lines are extending into the most remote sections of the intermountain country.

To indicate the magnitude of some of the irrigation works begun or contemplated under this act, it may be stated that a dam contracted for to store the waters of the Rio Grande, near the town of Eagle, New Mexico, to irrigate 180,000 acres, will be 225 feet high, 180 feet in width on the bottom and 20 feet on top and 1,150 feet across

the crest. The reservoir thus created is to have a capacity of 2,000,000 acre-feet or twice that of the famous Assuan dam in Egypt, and will be the largest artificial lake in the world. The dam is to cost approximately $5,300,000, and the entire scheme probably $7,200,000. The Gunnison tunnel in Colorado is another irrigation engineering project, to pierce the mountain and carry water from a large river through five miles of solid rock to reclaim 150,000 acres of land. Its aggregate cost will exceed $2,500,000. The government aid is not intended to discourage or interfere with a continuance of private enterprise, and the government is supposed to enter only fields where private capital is not strong enough to develop the opportunities properly or where, if left to individuals, the possibilities would be only partly utilized. Engineering skill, modern no less than ancient, has performed wonders in irrigation construction; great dams and reservoirs have been built, mountains tunneled, canyons spanned, depressions bridged, rivers diverted, and waters conducted in devious ways for long distances and by these means and by canals been made available to the land. Naturally irrigation has been most associated with arid regions; but, when pursued in many of the more humid sections, results have been obtained that proclaim its widespread beneficence.

Storage Reservoirs. The storage reservoir has come to be an essential part of irrigation schemes, and water for this purpose is mostly obtained from streams having their sources in the forests and melting snows of the mountains. In the springtime and early summer these streams are converted into swollen torrents, and in the earlier years their waters hurried to the oceans, unused, but they are being more and more diverted and stored to reclaim the dry lands. The early systems depended mostly upon the natural flow of the streams for water-supply, diverted by dams and canals, but in the growing season the streams were lowest, and, when water was most needed, it often was not available. This condition resulted in the extensive building of dams and storage reservoirs, in which are collected the flood-waters, thus not only insuring a supply when most needed but making possible the reclamation of vast additional areas hitherto accounted worthless. From these artificial lakes and reservoirs the waters are conducted into main canals and thence through lateral channels to the farms. A feature of the great enterprises undertaken by the government is the erection of works to collect and store these immeasurable flood-waters, making them available for distribution as needed. At the time of the passage of the reclamation act, however, irrigation systems had already been built along nearly