In my section of the country, we get most of our electricity from hydro, and we as consumers have the option to only buy power from renewable sources (hydro and wind).
And Baraka, there are other parts of the country that get their power from hydro as well. The
Tennessee Valley Authority's projects come to mind.
I'm not sure how practical it is in other parts of the country to construct large dams; furthermore, the funds for such superprojects aren't exactly forthcoming.