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In order to successfully carry out these objectives, much research is needed in water shed management. Better methods are needed for stabilizing slopes and streambanks to reduce the silt load of streams, and to regulate runoff from areas that have deteriorated from past intensive use. There is also a need for further studies of vegetative cover, both native and introduced, to halt the further spreading of erosion on steeper slopes and drainages. Ground-Water Investigations--Comprehensive quantitative investigations should be conducted in all developed ground-water basins throughout the Pacific Southwest. Potential yield appraisals are basic to orderly development and control of ground-water resources and are imperative wherever pumping is approaching or exceeding the perennial yield of the basin. These detailed investigations require qualitative data, such as: extent and configuration of the reservoir, identification and location of various occurrences of ground water, direction and gradient of movement, areas of recharge and discharge, and other hydrologic criteria. The quantitative data required include hydraulic characteristics of the aquifers, water chemistry, total pumpage quantities, recharge and discharge, all leading to a hydrologic inventory. Quantitative data in much of the study area are presently not available. The California Department of Water Resources has initiated such a program of investigations in southern California and has completed one major study. Others are programmed. There are no comparable comprehensive quantitative studies in the other States. Presently available studies are more qualitative in content and are based on limited data. Reconnaissance appraisals are proposed for those ground-water basins that have not been developed or investigated. Geophysical reconnaissance via gravity, aeromagnetic, and seismic methods afford a quick, first approximation of ground-water basin extent and configuration. Readily available geologic and hydrologic data would be collected. Basins which are known or are found to contain waters too poor in quality for immediate beneficial use would be delineated for possible salvage through future application of the desalting technique. Studies involving planned operation and management of ground-water basins should be an integral feature of long-range resource investigations. Much of the basic data needed for these investigations will have been accumulated for the potential yield appraisals. However, additional data of finer detail would be needed. This type investigation would reevaluate the overdraft and ground-water storage capacity available for seasonal and cyclic operation of local and imported water supplies. IX-4Epson Perfection 4870 Photo, 400 dpi, 8 bit, 14,129,152 byte