Conflicting Rationalities: Collision of hydro-power dam construction and water availability

Abstract

Abstract Using the Bui basin of Ghana as a case study, this study analyses the impact of hydro-electric dam construction on water health and yielding capacity of aquatic ecosystems. The study utilised remote sensing and GIS techniques as well as the Integrated Valuation of Ecosystem Services and Trade-Offs (InVEST) water yield model and Indicator of Hydrologic Alterations (IHA) analysis. Land use land cover maps and climate variables such as precipitation were integrated into InVEST to assess water yield levels. The daily river flow collected from the Bui Gauging Station were used to define streamflow characteristics along pre- and post-dam periods. The results shows that the construction of the dam significantly decreased water yields by 34,000 m3 and has negatively impacted the ecological integrity of riverine ecosystems within enclave as most hydrologic parameters of timing, magnitude and frequency recorded high alterations. The paper concludes by reflecting on the consequences of inadequate planning of hydro dams and possible pathways for addressing ecological, societal and environmental impacts of dam constructions.