Policymakers consider reoperation of existing hydroelectric dams an approach to partially restoring ecologies affected by the construction of the dam while maintaining some of the dams’ benefits. One version of reoperation is complete restoration of natural flow, otherwise referred to as run of river (ROR) operation. One dam being considered for ROR reoperation is the Akosombo Dam on the Volta River in Ghana. Because daily inflows into the Akosombo Dam exceed turbine capacity at the peak of the wet season, achieving ROR operation would require periods of spillage. Alternatively, we also consider a reoperation strategy that does not involve spillage but rather maximum turbine outflows throughout the wet season. We find that if annual generation stays essentially the same with increased wet season generation offsetting decreased dry season generation, the increase in costs is $20 million to the West African Power Pool. If annual generation decreases due to spillage, as in our ROR scenario, system-wide costs are $60 million.