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Show a pond or diversion on a dry water course which may drain flood waters from 50 to several hundred acres of grazing land. Water from the pond spill- way or diversion is channeled to a relatively level area below, where by means of a sirup pan system of terraces, the flood water is spread over the area. Such systems, during rainstorms, provide extra water for an area usually less than a tenth the size of the runoff area. Either native grasses or alfalfa may be used as the hay crop. As the cost of such installations is relatively low, usually from $30 to $50 per acre, ranchers can well afford them. They will generally return their cost in from 2 to 10 years. However, technical help is usually needed to select feasible sites and to design and lay out the system. Most ranch units do not include lands in the shoestring or other valleys to which irrigation proj- ects are limited. Thus they must improvise their own systems, which they are doing rapidly and suc- cessfully. Soil conservation districts in the range areas have been especially active in promoting flood irrigation and water spreading developments. The districts in the Missouri Basin, with technical assistance by the Department of Agriculture, have completed plans for flood irrigation of 230,000 acres, of which about 128,000 are now watered. Nearly 80 percent of the installation has been put into operation in the past 5 years, and over 20 per- cent was installed during 1949. The Buxeau of Land Management has success- fully undertaken this type of work on the Powder River Grazing District near Alzada, Mont. The area involved is almost 1,000 acres, of which 760 acres were benefited by water spreading. The area was overgr-azed, with widespread sheet erosion and many gullies from 4 to 10 feet deep. Dikes were built on thte contour. The dikes and increased vegetation have in 5 years effectively controlled erosion. Sediment be- hind the dikes has partially filled the old gullies. Where soil receives much water, sagebrush and cac- tus have given way to dense western wheat grass. Where the flooding is lighter, sagebrush and wheat grass grow together. Prior to this work, the area had a grazing capacity of 120 animal unit months. Afterward, its capacity was 420 animal unit months, an. increase of 250 percent. The increased grazing capacity will pay costs of construction and maintenance in 40 years, with an annual return of 13 percent on the original investment. The value of the lancl also increases through range stabiliza- tion and lowered costs of livestock operations. 226 Of the 30 or more million acres of public lands used for grazing, perhaps 1 million acres can be given some type of flood irrigation, or related water conservation work, as an effective means of in- creasing forage and reducing erosion. The same type of flood irrigation is possible in perhaps 2 mil- lion acres of private grazing and pasture lands. Conclusions Much land use integration is possible in the Mis- souri River Basin development program. It will help substantially to stabilize the agricultural and business economy. Such integration can be stimulated by an educational program designed to encourage the production of forage crops on ir- rigated lands as a part of the regional livestock economy. Integration and greater livestock production can also be stimulated by flood irrigation by relatively simple methods. These will help increase the for- age productivity of the range, and at the same time assist in controlling erosion. Perhaps 3 million acres of land in the basin can be so treated. The increase in forage production on the irri- gated lands should be directed toward relieving the pressure on the range land. Many cattlemen are finding that modern irrigated pasture seeded with mixtures of clover and smooth brome has great advantages when used in connection with range. The increase in forage production in the irri- gated lands will tend toward greater pressures upon public land administrators to grant room for added stock. Such pressures should be resisted. Public lands are now grazing stock beyond their carrying capacity. These lands need a rest to recover their productivity. Legislation is needed which might grant a grazier on public lands an equity in an irrigation enterprise equivalent to the value of his grazing rights and privileges, which he would sur- render to the Federal Government. The lands thus released would not be used until restored to full productivity, and then used only to reduce grazing on adjacent lands. Thus some reductions in use of overgrazed public ranges could be achieved. 5. Appropriateness of Present Acreage Limitation Laws The Problem Suitability of acreage limitation laws for land- holding in the basin and difficulties resulting from their application. |