Reservoir storage is necessary to use the highly variable water resources of a river basin for beneficial purposes such as city water supply, industrial water supply, irrigation, and hydroelectric power generation. Dams and other appropriate structures also regulate rivers to reduce damages and wastage of water caused by floods, drains to sea and by inadequate allocation. Water quality, environmental resources, protection and enhancement of fish and wildlife, and other environmental resources are important considerations in managing reservoir (river) system. We present here the linear programming model for three reservoirs for the allocation of scarce water keeping in view the priority factor.