Impacts of Flow Regulation on the Aquatic Ecosystem of the Peace and Slave Rivers

This report synthesizes research on one of the ten guiding questions in the Northern River Basins Study: how river flow regulation impacts the aquatic ecosystem. The report begins with a review of the state of river diversions and modified flow regimes within Canada, and the ecological impacts that are known or likely to occur from regulation of large northern rivers. It then provides a biophysical description of the Peace and Slave rivers and delta systems, and synthesizes results of various scientific reviews and field/laboratory studies. Topics of those studies include flow regulation of the river main stem and the Peace- Athabasca delta, modelling of hydraulic flood routing, regulation effects on the ice regime, fluvial geomorphology and vegetation regimes, water chemistry effects, and effects on aquatic and riparian ecosystems. The report concludes with a summary of the major results and a compendium of scientific recommendations for modification of existing conditions, monitoring of future trends, and future research.