Effects of hedging on reservoir performance

The effects of operating a water supply reservoir with a policy of hedging on various reservoir performance criteria are investigated. The results of simulations where policies with different degrees of hedging are adopted are used to determine how reliability, resiliency, and mean and maximum deficit vary as functions of hedging parameters and to derive the relationships between these criteria. It is found that the standard operating policy is the best in relation to reliability and resiliency and is satisfactory with regard to deficits. Hedging improves the performance with respect to mean deficit if it is started with sufficient water in storage. If hedging is applied when there is little water in storage, it reduces the risk of very large future deficits, although the mean deficit will be increased. If hedging is continued even when the demand can be supplied, the performance of the reservoir will be more stable and the mean deficit will be decreased, but these will be achieved at a cost of increasing the rate of failure.