Preserving biodiversity downstream of hydropower plants
© 2013 EPFL
As Switzerland considers expanding its hydropower capacity, in particular with small hydropower plants, the environmental impact of this renewable energy source has come under scientific scrutiny.
Last year, with funding from the Landolt Chair for Innovations for a Sustainable Future, researchers at ENAC focused on rethinking the way that water is released to rivers. While today’s policy of ensuring constant minimal outflow thresholds of water may keep rivers from running dry and protect a few aquatic species, they fail to reproduce the natural variability found in natural river ecosystems at the cost of ecological biodiversity. Dynamic release policies provide one way of getting around this by artificially reproducing some of the variability found in natural rivers. By considering the utility of the water allocated to the riparian environment and its economic meaning, Paolo Perona and his colleagues argue that increasing downstream flow variability could improve ecosystem performance and reduce the need for river restoration programs in the future without necessarily implying losses in electricity generation.