Reducing adverse impacts of Amazon hydropower expansion

Proposed hydropower dams at more than 350 sites throughout the Amazon require strategic evaluation of trade-offs between the numerous ecosystem services provided by Earth's largest and most biodiverse river basin. These services are spatially variable, hence collective impacts of newly built dams depend strongly on their configuration. We use multiobjective optimization to identify portfolios of sites that simultaneously minimize impacts on river flow, river connectivity, sediment transport, fish diversity, and greenhouse gas emissions while achieving energy production goals. We find that uncoordinated, dam-by-dam hydropower expansion has resulted in forgone ecosystem service benefits. Minimizing further damage from hydropower development requires considering diverse environmental impacts across the entire basin, as well as cooperation among Amazonian nations. Our findings offer a transferable model for the evaluation of hydropower expansion in transboundary basins.

Automated summary

The proposed hydropower dams in the Amazon region require strategic evaluation due to the various ecosystem services provided by the river basin. Using multiobjective optimization, this study identifies portfolios of sites that minimize impacts on different aspects while achieving energy production goals. The uncoordinated dam-by-dam expansion has led to the loss of ecosystem service benefits, highlighting the importance of considering diverse environmental impacts and cooperation among Amazonian nations.