With the current increase in electricity generation from renewable energy sources, pumped-storage plants have been used for energy storage purposes, to guarantee the supply of electricity and reduce the impact of intermittent sources in the grid. In addition, there is an increased demand for water management solutions due to changes in climate and population increase. Seasonal pumped-storage comes as an alternative to store both energy and water with the intention to optimize hydropower generation, increase energy and water supply security, support the introduction of intermittent renewable energy sources to the grid, enable the construction of new hydroelectric dams in cascade, reduce the dependence on thermal generation, lower transmission costs, control floods and mitigate conflicts over the multiple uses of water. A case study in the Zambezi River Basin compares a conventional reservoir dam with a seasonal pumped storage plant, with the same storage volume. This comparison shows that seasonal pumped-storage has higher construction costs than conventional reservoir dams, however, as seasonal pumped-storage has much lower land requirements and evaporation losses, it becomes more attractive to conventional reservoir dams in locations with plain topography and where water is scarce.