A small hydropower dam in Brazil.Victor Baptista
The development of small hydropower dams is widespread throughout Brazil and elsewhere in the world, vastly overshadowing large hydropower projects. The proliferation of these smaller dams is a response to growing energy and security needs. Their expansion, however, threatens many of the remaining free-flowing rivers and biodiverse tropical regions of the world interrupting the migrations of freshwater fishes, on which millions of peoples’ livelihoods depend.
A new University of Washington paper published Jan. 11 in Nature Sustainability quantifies these tradeoffs between hydroelectric generation capacity and the impacts on river connectivity for thousands of current and projected future dams across Brazil. The findings confirm that small hydropower plants are far more responsible for river fragmentation than their larger counterparts due to their prevalence and distribution.