Operating Policies For Reservoir Pumped‐Water Interties

Abstract

One means to increase effective water supply yield is to have pumpedwater intertie of reservoirs. The management of Hoover Reservoir and its associated pumped‐water intertie with Alum Creek Reservoir in the water supply system of Columbus, Ohio, is examined using the method of implicit stochastic optimization. Optimal monthly pumping policies are derived in a multiobjective environment involving trade‐offs of pumping and water supply shortage costs, target draft rates, and reliability levels. Policies heuristically derived from a dynamic programming formulation are tested for statistical performance using simulation, and are parametrically varied to determine the most cost‐effective policies for a given reliability level and draft rate. Multiobjective trade‐off analysis can then be carried out between pumpage cost, target draft rate, and reliability. In the case study, significant net savings result from the use of pumped water rather than alternative water supply sources due to lower softening costs, and a savings maximization procedure is developed. The advantages and disadvantages of implicit stochastic optimization are highlighted.