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Show 11. Conflicts Between Recreation and Other Uses in Reservoir Operation The Problem Resolution of conflicts between recreation and other beneficial uses in the operation of storage reservoirs. The Situation Reservoir projects for the dual purpose of flood reduction and low stream flow regulation are oper- ated normally at a median lake level. At times of flood, lake levels will be temporarily raised, and at times of low river flow, lake levels will be lowered for downstream benefit. A conflict arises when recreation ©r other interests desire a constant level lake which would preclude the downstream uses of the stored water. Recreation interests may also desire a continuous flow downstream from reservoirs. Maintenance of an adequate flow in the streams below dams and regulation of the temperature of these waters will be significant problems in many of the projects which provide for high dam construction. Accord- ing to the proposed plans of operation for certain projects, minimum stream flows below the dam will be increased, but discharge through the dam will not be continuous and there will be brief periods of interrupted stream flow. Discharge of low-temperature waters from lower strata in im- poundments may eliminate warm water fisheries for several miles downstream. To replace such losses, it may be necessary to establish a trout fish- ery which could probably be achieved by annual introduction of desired species. Conflicts have arisen in the Ohio River Basin be- tween recreation interests and others over plans for conservation storage reservoirs concerning the selection of project sites, the establishment of the pool level, the method of reservoir operation and the over-all basin plan for using reservoirs to obtain a dependable water supply. In view of the reser- voirs yet to be constructed these conflicts will arise in other cases. The following are examples of con- flicts which have already arisen. In the case of the Cagles Mill Project in the Wabash Rrver Basin, now under construction by the Corps of Engineers, local interests opposed pro- vision of conservation storage capacity in the proj- ect for power production since the operation of such storage capacity would necessitate fluctuation in the water level of the conservation pool. These interests desired a conservation pool for recreation purposes but contended that a draw-down of the reservoir sufficient to develop power on an economic basis would destroy the recreation values. It was their opinion that these values were greater than the power values that would be foregone. The plan for the authorized Rocky Fork Reser- voir on a branch of Paint Creek of the Scioto River Basin calls for flood control above a normal lake level but no draw-down for increasing low flow downstream. In this case, downstream benefits will be sacrificed to provide an optimum recrea- tion value. This reservoir project is part of a plan for several reservoirs in the Scioto River Basin, and it may be possible to modify the Paint Creek Res- ervoir so that it may operate in tandem with Rocky Fork. The two reservoirs could then be operated, one for constant recreation level and the other for low flow improvement of the Scioto and Ohio Rivers. In the case of Pymatuning Reservoir on the Shenango River, Pennsylvania has constructed a reservoir which is operated in the interest of flood control, recreation, and improvement in stream flow downstream. The upper end of the reservoir is separated by a secondary dam operated at con- stant level. This area has become a sanctuary for fish and wildlife. The steeper shores of the down- stream part of the reservoir are used successfully for fishing while the surface level is drawn down to in- crease the low flow in the months of August, Sep- tember, and October. This reservoir operation is successful for several purposes, including pollution abatement, and is an example of careful planning to resolve reservoir operation conflicts. Conclusions For beneficial use, reservoirs must be considered as a comprehensive system and each project should be planned both for its best use in view of other existing and potential reservoirs which can be co- ordinated to provide for all needs. In the resolu- tion of local conflicts, reservoirs should be consid- ered as parts of an operating system rather than as separate projects. 12. Conflicts in Water Use for Supplementary Irrigation The Problem To what extent does the expansion of supple- mentary irrigation conflict with other uses of water? 682 |