Within the energy community, conventional dam and reservoir-based hydroelectricity is often viewed as a low- cost, immediately available zero-carbon resource that could facilitate more intermittent renewable electricity integration, seasonal storage, and other grid benefits. Conventional hydroelectricity systems, however, are po- tentially unique among power plants in that energy provisioning is not the only priority for their fuel, stored water. This paper presents a record linkage between electricity- and dam management-oriented datasets to facilitate attention to the fundamental challenge of altering operational regimes for systems that have other uses.