Lake Modeling Reveals Management Opportunities for Improving Water Quality Downstream of Transboundary Tropical Dams

Water quality in tropical rivers is changing rapidly. The ongoing boom of dam construction for hydropower one the drivers this change. In particular, stratification reservoirs induces oxygen deficits their deep waters and warmer surface water temperatures, which often translate into altered thermal regimes downstream river systems, with cascading consequences entire aquatic ecosystem. Operation rules reservoirs, involving intakes at different levels, could mitigate quality. However, optimized management relies on predictive models quality, but such capability lacking dams. Here we focus Zambezi River Basin (southern Africa) to address gap. Using one-dimensional General Lake Model, reproduced internal dynamics transboundary Kariba, world’s largest artificial lake by volume, created damming border between Zambia Zimbabwe. Through modeling approach, assessed quantified alteration reservoir. Results suggest that these alterations depend directly Kariba’s dynamics, its level policies withdrawal from Scenario calculations indicate a large potential mitigating implementing hypothetical selective technology. show cooperative existing infrastructure Kariba Dam has most actual alterations.