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and the effect on streamflow is a complex area and needs more definitive studies, Conservation and Management Materials furnished by WRC referred to as non-volumetric requirements left much to be desired. Information furnished on environmental resources was very sketchy, No information was furnished on sedimentation, erosion, navigation or water quality. Data furnished on fishing, water-based hunting and water-oriented recreation are considered too gross to be of any practical use. The SRF attempts to describe in rather broad but yet definitive terms the environmental resources, bank and sheet erosion problems, sedimentation, water- oriented recreation needs and problems, Missouri River navigation conflicts and water quality aspects. Other The MCC attempts to show water availability and use for average condi- tions and for dry year conditions based on yearly flow data. It also attempts to show analyses based on monthly flow data and water use for average and dry year conditions. The SRF attempts to show only water availability and water use based on average annual flows and water use. It is believed that a nationwide appraisal or one that covers an area as large as the Missouri River Basin should not attempt appraisals beyond average conditions. The only flow data provided is at the outflow point of each ASA. Although changes in water availability at the outflow point of ASA's may provide signals that water shortages may be occurring upstream or are projected to occur, these changes do not show where the problems are, the nature of the problems, or that there may even be a problem. Analyses of monthly flow data as presented cannot possibly consider the reregulating effectiveness of reservoir storage or the availability of storage to satisfy any of the needs within an ASA. The six- reservoir main stem system provides storage equivalent to about three times the average annual flow at Si oux Ci ty. In additi on, there are about 60 federally constructed tributary reservoirs of varying capacities, which total does not include numerous SCS, state and other reservoirs. State and federal agencies engaged in water resources planning in the Missouri River Basin are well aware of problems and problem areas although the solutions to the problems are not as apparent. Water use in the basin, particularly for crop irrigation, has been escalating rapidly during the last several years. This has been brought about largely by higher prices for farm commodities and use of ground waters and sprinkler irrigation. There are extensive underground reservoirs of water at many locations in the basin and extensive use is being made of this available water supply. Most of the new irrigation in the basin from ground water sources and some of that from surface sources utilize sprinklers which are more efficient in the use of water than spreader type irrigation which relies on ditches and gravity flow. With limited water supplies, it is apparent that water shortages will occur at many locations. The effect of using large quantities of ground water on streamflow presents a complex problem which cannot be properly analyzed in a study of limited scope such as the National Assessment. The relationship of ground water use to streamflow is different in every area in the basin and will require detailed study. In some areas the relationship appears to be direct while in other areas there may be little or no direct effect or it may take years before the effects show up on streamflows. III- 14 I I I I I I I I I I I I I I I I I I I