Dam operations may improve aquatic habitat and offset negative effects of climate change

Dam operation impacts on stream hydraulics and ecological processes are well documented, but their effect depends on geographical regions and varies spatially and temporally. Many studies have quantified their effects on aquatic ecosystem based mostly on flow hydraulics overlooking stream water temperature and climatic conditions. Here, we used an integrated modeling framework, an ecohydraulics virtual watershed, that links catchment hydrology, hydraulics, stream water temperature and aquatic habitat models to test the hypothesis that reservoir management may help to mitigate some impacts caused by climate change on downstream flows and temperature. To address this hypothesis we applied the model to analyze the impact of reservoir operation (regulated flows) on Bull Trout, a cold water obligate salmonid, habitat, against unregulated flows for dry, average, and wet climatic conditions in the South Fork Boise River (SFBR), Idaho, USA. •We present an application of integrated model to analyze impacts of reservoir management on downstream aquatic habitat.•No significant difference between regulated and unregulated flows regardless of climatic conditions.•Reservoir management maintained quality habitat during a series of drought climatic years.•Reservoir management may mitigate impacts of future climatic variability and climate change on aquatic habitat.