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Show PART IV RESOURCE AVAILABILITY The availability of this water for future use is limited by physical conditions including the availability of water at or near proposed uses. Other constraints include institutional regulations which must recognize compacts and water laws, patterns of use which determine the extent of storage regulation required, and economic considerations and impacts. The maximum recoverable ground water in the upper 100 feet is esti- mated at 17 million acre-feet; because of poor permeability, an addi- tional 98 million acre-feet is not readily available. Only 132,000 acre- feet was pumped in 1965. Economics and water quality considerations may limit large-scale developments in the future. Land All of the 72.6 million acres (including water surface area) are presently being used for one or more purposes. Lands presently suitable and available for development under the multiple-use concept are (l) grazing lands - ^k.6 million acres; (2) commercial timber production - 9.4 million acres; (3) 1.6 million irrigated acres present, plus 7 mil- lion acres potentially irrigable without considering water development; (k) dry cropland - 603,000 acres; (5) sufficient amounts, although not fully inventoried, for wilderness, primitive, outstanding national, his- toric, cultural, and scenic rivers; (6) urban, industrial, transportation, and utilities; (7) developed recreation, fish and wildlife; and (8) de- veloped minerals. About kl million acres have been identified as key habitat for wildlife. Nearly all public land is available for extensive use as undeveloped recreation and hunting areas. Other Resources Agriculture If an economic water supply can be obtained, potential exists for ir- rigation of over 7 million acres of new land. About one-third of exist- ing irrigated lands need additional water for best production. Irrigated cropland yields can be increased greatly by providing supplemental water, installing drainage systems, improving irrigation systems, and adopting cultural management practices. Selected suitable areas totaling 603,000 acres are dry-farmed and will continue as such except for those acreages converted to irrigation. Dry cropland production can be increased by improving cultural management practices such as use of improved varieties, conserving soil moisture, maintaining soil fertility and reducing erosion. 39 |
