That's debatable - Quebec generates close to 50% of Canada's Hydro power and has been part of world leaders in the field. The province has been pretty competent in the past decades - of course with challenges - but the rest of Canada would be lost without Hydro-Quebec being behind most projects and investments (expertise, management, financing...)
Ontario has lots of hydro including Niagara Falls, BC has the new site C.
What I’m saying is Canada has the potential to generate more hydroelectricity but environmental concerns largely delay or prevent further expansion.