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There is also a major problem which develops below the reservoirs constructed on the Colorado River and its tributaries concerning the degradation of the river channel due to the release of clear water from the dam as compared with the historic flow of sediment-laden water. Data on this phenomenon must be available to make accurate degradation and tailwater analyses. Stream hydrograph analysis is necessary to verify or improve techniques presently used to estimate design floods for proposed dams in the Lower Colorado River Basin. These studies involve the detailed analysis of observed large floods and factors influencing the runoff and its distribution. This study is essential in the spillway design which was previously discussed. In the field of more efficient water use and salvage of nonbeneficial consumptive use, research is conducted in runoff fore-casting, water salvage by eradication of phreatophytes, irrigation water requirements, tolerable irrigation water shortages, and sediment transport. Long-range studies on these elements have been programmed to assist in the determination of available water supply for future uses and to firm up the determination of water requirement analysis. Methods of forecasting inflow of reservoirs is a relatively new science, and studies must be continued to improve the techniques now employed. Forecasts now are based on the correlation of runoff with snow measurements on the watershed. Past study of this technique has improved the quantitative forecasts during recent years. Continued study is planned to be given to this type of analysis as well as an attempt to forecast runoff to be produced by rainfall. A procedure by which forecasts of inflow to reservoirs could be made several months in advance would be invaluable in river operation procedures and in decreasing operational waste of water. Water salvage studies in the Lower Colorado River area by the eradication of phreatophytes have been carried on for several years and are programmed for future years. The eradication of phreatophytes in the flood plains of rivers provides one of the best means of water salvage known in the basin. Continued study will be required to develop new and improved procedures for eradication of these plants to obtain water salvage at a justifiable cost. The study of irrigation water requirements is necessary so the greatest use possible can be made of the water supplies available. Past practices in the Lower Colorado River Basin have not always been limited to ideal irrigation requirements due to the abundance of water supply available. In future years, under restricted water supplies, it will be imperative that water users be restricted to more nearly ideal irrigation water requirements if the greatest use IX-7Epson Perfection 4870 Photo, 400 dpi, 8 bit, 14,270,464 byte