RICHARD resiah HINTON. [Special Agent in charge of Artesian Wells Investigation, 1890, BEING A SECOND EDITION OF MISCELLANEOUS DOCUMENT NO. 15, WASHINGTON: GOVERNMENT PRINTING OFFICE. 42 IRRIGATION IN THE UNITED STATES. EXTENT AND METHODS. AREA OF RECLAMATION. THE STATISTICS' PREPARED BY RICHARD J. HINTON. BEING A SECOND EDITION OF SENATE MISCELLANEOUS DOCUMENT No. 15, 49th CONGRESS. 138 A L-AP VOL IV——1 IRRIGATION IN THE UNITED STATES. [Prepared by order of the United States Senate Special Committee on Irrigation and Reclamation of Arid Lands. ] PART I. THE ARID REGION. An inquiry into the progress and present condition of irrigation in 'this country necessarily involves a consideration of the extent and character of the area within which the annual rain-fall is not sufficient for the industrial uses of the people. Such an inquiry, broadly defined, involves the extent of the fall of rains or snow within the area indicated; also the evidence obtained as to increase or decrease of precipitation resulting from agricultural settlement or of pastoral occupation, the increase of humidity of earth or air, the destruction of the timber mainly by its use for settlement purposes, the effect of the destruction of the native grasses and the substitution of cultivated varieties; also the sources of water supply, their character, uses, conservation, the means, natural and artificial, employed for their distribution, and what has been and is being accomplished in the way of artificial methods of water distribution and economy, and the laws and customs pertaining thereto. More than af these, however, it relates itself fundamentally to the largest quess of physical geography. The topographical configuration involve deed it controls, the whole matter of aridity, because it determines all climatic considérations. The probability of reclamation by means of irrigation is primarily by the configuration of a given hydrographic area. Incidentally, the questions arising from deforesting, on the one hand, and of arboriculture, on the other, are related to the inquiry, and have been brought out to some extent. The aim has been to give the actual facts upon these subjects, so far as they could be supplied from observation, experience, experiments, and realized results. This effort has been measurably successful. It has brought together a mass of facts and observations that shed much light on the questions involved, giving a broader idea of the importance of irrigation, and adding greater value to a very large area of the United States, of whose agricultural capabilities but small account has heretofore been taken. It will be developed by the facts herein presented that the area of the irreclaimable arid lands within the boundaries of the Union is, comparatively speaking, quite moderate in its extent. There is, however, a very large area, embracing at least one third of our total land service, wherein the water supply, whether subterranean and surface-flow or in the form of precipitation, is both inadequate and irregular in character. The eastern boundary of this great area may at present be assumed to be the one hundredth meridian of west longitude. The western boundary may be in part placed at the Pacific Ocean, though more ac 3 |