OCR Text |
Show basins outside the present critical areas as possible interim sources of water that might be conveyed to areas of need; and (3) investigation of the possibility that some irrigated agriculture will be displaced by urban development or by depletion of ground-water supplies to outlying ground-water basins. Since development costs would undoubtedly be high, assurance would be needed as to the long-term yield of these basins and the prospects for capital recovery. Studies should be continued in the fields of reuse of water, precipitation management, and evaporation suppression. Although these augmentation means are not expected to offer a large potential for solving the Region's water problems, they could help reduce importation requirements and provide an interim water supply until an imported water supply can be made available. Studies of the technical problems associated with the importation of water to the Region should be initiated immediately. Existing legis- lation will, for all practical purposes, limit these studies to desali- nation until the year 1978. More reliable data are needed for estimating cost of desalting water in the large quantities that would be necessary to satisfy projected regional water requirements. A prototype desalting plant of much larger capacity than those presently in operation could provide the needed data. Potential plant sites, conveyance routes, and water exchange schemes should be investigated in considerable detail. An inventory is needed of the sources, quality, and sufficiency of water supplies available for use by the small rural communities of the Region. Water Quality Studies Studies of the quality of the ground water from aquifers in the Gila Subregion are of particular importance. The exceptionally effi- cient use of water in the Subregion allows only insignificant outflows from the area. Due to the nondegradability of the salts present in the natural water supplies, the progressive concentration of salts is per- petuated and ground-water quality is degraded. Studies should determine the rate of quality degradation to be anticipated with the projected rates of ground-water overdraft and with augmentation programs of vari- able scope. Alternative solutions to the degradation problem should be evaluated. Additional studies are also needed of alternative means of waste water treatment and to provide for the most efficient reuse of reclaimed water. Evaluation of the anticipated degradation of water quality in the Colorado River and how an imported water supply could best be managed to alleviate this degradation are also needed. |