While hydropower offers a number of advantages over other energy sources, it also faces some unique environmental challenges. Notable disadvantages of hydropower include the following:

  • Dam and reservoir can affect natural water temperatures, water chemistry, river flow, and silt loads, which can negatively affect native plants and animals
  • Manufacturing of the dam can produce emissions if fossil fuels are used to make the concrete and steel[1]
  • High investment costs
  • Hydrology dependent (dependent on precipitation)
  • In some cases, inundation of land and/or wildlife habitats
  • In some cases, loss or modification of fish habitats
  • Fish entrainment or passage restriction
  • In some cases, there may be changes in reservoir and/or stream water quality

In some cases, the establishment of hydropower projects can result in the displacement of local populations[1]

Updated by Erin Bennett, June 2022