The Economics of Land Classification for Irrigation

Abstract

A SOUND appraisal of the land resources of a proposed reclamation project has ah economic importance that cannot be emphasized too strongly. The earliest land classification work of the Bureau of Reclamation began when the first projects were investigated and authorized in 1903. The primary purpose was to delineate the area which could be served. The chief factor considered was the elevation of the land in relation to the water surface elevation in the laterals, Smoothness and degree of slope was considered also, as was freedom from timber, rock, brush and other obstructions, but the limits placed on irrigability were very wide and not precisely defined. Soils analysis played little part in the early classification scheme' Such soils information as may have been available to the planners of early projects was passed over lightly or ignored entirely. An early report (about 1910) states, "A topographic survey reveals all the essential facts necessary for wise selection (of irrigable land) and collects and assembles the facts in the cheapest and most thorough manner. ''~ The Department of Agriculture made soil surveys of some of the earlier projects. A good example of this type of survey is found in the Strahorn report on the Belle Fourche Area of South Dakota3 In this examination about 1~1,000 acres were covered. Of this, about 80,000 acres were described as clays and clay loams, extremely tenacious, with alkali present and no evidence of downward movement of water. About ~7,000 acres were described as good agricultural land, much of which was already being irrigated; and about 14,000 acres were reported mixed in character. This information, though valuable to the Bureau of Reclamation and to the prospective settlers, was too little and too late. It was too late because the project was under construction two years before the * This paper expresses the personal views of the author and does not necessarily reflect the opinions and policies of the Bureau of Reclamation.