Water Resources Management 10: 463478, 1996. @ 1996 Kluwer Academic Publishers. Printed in the Netherlands. 463 Sensitivity of Reservoir Operation Performance to Climatic Change DONALD H. BURN and SLOBODAN P. SIMONOVIC Department of Civil and Geological Engineering, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Received: 2 May 1995; in final form: 15 August 1995) Abstract. The potential impacts of changing climatic conditions on the operational performance of water resource systemswas investigated in this paper. A multi-site streamflow generation model was used to synthesizepotential monthly flow sequences reflecting two different sets of climatic conditions. The generated data were subsequently employed as input to a reservoiroperation model that was used to determine the reservoir response to the inflow resulting from the implementation of the reservoir operating policy. The performance of an example reservoir system,the Shellmouth Reservoir located in the Canadian province of Manitoba, was evaluated and compared for the two sets of conditions. The operational performance wasevaluatedin terms of the reliability of the system for meeting the three purposesof the actual reservoir. The reservoir performance was determined to be sensitiveto the inflow data. The results indicate that climatic change has potentially important implications for the operation of the example reservoir system. Key words: climate change; reservoir operation; streamflow generation. 1. Introduction A variety of possible hydrologic impacts resulting from climatic change have been hypothesized (Gleick, 1989; Houghton et al., 1990). Some of the potential climatic change impacts on hydrology that have been identified include changes in the availability of water supply (Revelle and Waggoner, 1983; Gleick, 1987) changes in runoff production (Gleick, 1986; Lettenmaier and Gan, 1990), and changes in the timing of hydrologic events (Lettenmaier and Gan, 1990; Kite, 1993; Burn, 1994). As a result of the potential hydrologic impacts of climatic change, there are also likely to be many water resource systems that are affected by climatic change. The World Climate Program, initiated by the World Meteorological Organization, documented the need for research in this area. Nemec and Schaake (1982) raised the issue of: “whether the sensitivity of the water resource system to climate variations is so small that it can be included in the modeling error, and the water system so robust that it will not even feel it, or is it large enough to be taken into account?’ Following the work of Nemec and Schaake (1982), Klemes (1985) performed an assessment of the anticipated sensitivity of water resource systems to climatic variations. His findings were that: (a) the decrease in reliability might occur much