Hydro-electricity is the most significant household and business energy source in Christchurch. Hydroelectric plants operate where suitable waterways are available; many of the best of these sites have already been developed.
Generating electricity using water has several advantages. The major advantage is that water is a source of cheap power and that hydro generation is a renewable energy source.. In addition, because there is no fuel combustion, there is little air pollution in comparison with fossil fuel plants and limited thermal pollution compared with nuclear plants.
Like other energy sources, the use of water for generation has limitations, including environmental impacts caused by damming rivers and streams, which affects the habitats of the local plant, fish, and animal life.