Quantifying the trade-offs in re-operating dams for the environment in the Lower Volta River

• DOI: 10.5194/hess-2022-270
• Publication Date: 2022-08-04T14:21:45Z
• Authors: Afua Owusu; Jazmin Zatarain S...; Marloes Mul; Pieter van der Zaag; Jill Slinger
• Keywords: Dominance (genetics); Hydroelectricity

Abstract. The construction of the Akosombo and Kpong dams in Lower Volta River Basin Ghana changed downstream riverine ecosystem affected lives communities, particularly those who lost their traditional livelihoods. In contrast to costs borne by vicinity river, as a whole, has enjoyed vast economic benefits from affordable hydropower, irrigation schemes lake tourism that developed after dams. Herein lies challenge; there exists trade-off between water for river ecosystems related services on one hand, anthropogenic demands such hydropower or other. this study, an Evolutionary Multi-Objective Direct Policy Search (EMODPS) is used identify multi-sectorial trade-offs exist Basin. Three environmental flows, previously determined are incorporated separately objective. results highlight dominance production Volta, but show room providing flows under current climatic use conditions if firm energy requirement Dam reduces 12 % 38 depending flow regime implemented. There uncertainty climate change effects runoff region, however multiple scenarios investigated. It found leading increased annual inflows environment while resulting lower provide opportunity strategically dry season is, reduce sufficiently meet low requirements key clam fishery. This study not only highlights challenges balancing considerations managing existing dams, also identifies opportunities compromise River.