The development and allocation of the water resourcse within a state require water planners to prepare plans far in advance of the actual time new facilities are required. It is not easy to identify and evaluate all the possible alternatives for providing water which incorporate broad objectives such as economic efficiency, social welfare, regional development, recreation benefits, and conservation of environment. Water resources development entails the modification of a natural hydrologic system to better meet man\u27s needs. The interrelationships among elements of the hydrologic system to better meet man\u27s needs. The interrelationships among elements of the hydrologic system are relatively simple in comparison to the social, legal, economic, and institutional interdependencies involved. The relationships are so complex as to require that planning of water resource development be accomplished on a systems basis. It has become apparent that water resource planning must consider mass transfer of water encompassing areas which have potential for economic growth competing with other areas already highly developed economically. The wisest political decisions and the greatest benefit to the public will result if a method is used to explore the probable consequences of alternative water resources development and management policies and plans. The objective of this study is to extend the capability of systems analysis and operations research to the problem of interregional planning of water resources allocation for the State of Utah. The hydrologic characteristics and cost of water in each of the ten hydrologic study units of the state were determined. Hydrolgoci data from hydrologic inventories and estimates from the Utah Division of Water Resources were used to determine availability, reservoir storage-draft relationships, evaporation loss from reservoirs, agricultural use return flow, and municipal and industrial use return flow. Cost data were developed for storage facilities, diversion and canal works, artificial recharge facilties, treatment of waste water, and treatment of municipal supply. Supply functions for water in each of the ten hydrologic study units of the state were determined. Two sets of functions were developed--one for agricultural use and one for municipal and industrical use. Parametric linear programming was employed to develop a function map of the shadow price (marginal cost) of water for each of the two uses. The shadow price of imported water (value) to each of the study units was also determined to show the possible economic consequences of inter-basin transfers. In general, imported water was of little or no value if water presently being evaporated from Great Salt Lake is available for diversion upstream. A statewide model was developed to determine a least-cost allocation of water resources to meet projected requirements. This linear programming allocation model was developed subject to constraints such as hydrologic characteristics, limits on inter-basin transfers, limits on artificial groundwater recharge, and existing water requirements. Parametric programming was utilized to determine the impact of changing availability which reflects policies regarding inflow requirements of the Great Salt Lake and interstate agreemetns, increased agricultural use and municiapl and industrical use which reflects population increases projected for the future and changing groundwater availability which reflects legal constraints. The primary facotr affecting inter-basin transfer of Colorado River water is the degree to which evaporation from Great Salt Lake is reduced
