Megadams such as those operated by Hydro-Quebec have tremendous impacts on natural water cycles that have taken millennia to develop. Hydro-Quebec dams withhold 50 to 70 percent of the spring runoff in order to generate electricity in the winter. These cold and nutrient-rich waters that are supposed to run-off into the ocean are now being held up in reservoirs thousands of acres in size.

The withholding of this water has tremendous impacts on biodiversity and the health of the oceans as can be seen in the statement below.