Macroinvertebrate Recovery to Varying Hydropeaking Frequency: A Small Hydropower Plant Experiment

As the demand for hydroelectricity progresses worldwide, small hydropower operators are increasingly examining feasibility of using existing infrastructure (e.g., settling basins) in run-of-the-river schemes intermittent power production. Such flexible production causes short-term discharge fluctuations (hydropeaking) downstream reaches with potential adverse effects sensitive fauna and flora alpine streams. In an experimental field study on a previously unregulated section upper Rhone River (Switzerland), we measured density composition macroinvertebrate drift two habitats (riffle, pool) following 15-minute hydropeaking wave. The was replicated five times over 14 days decreasing recovery between peaks (8, 3, 2 days, 24 h), measurements were compared kick samples benthic community. Results from sampling showed that abundance did not significantly change peaks. There habitat specific reactions to hydropeaking, pool experiencing more pronounced abundances than riffle. Overall, correlated time, but results indicate taxa-specific differences. This research advocates importance completing in-situ experiments order better understand ecological impact plants.