run-of-the-river hydro projects probably have their place. It's a scale of magnitude. Usually designers are inclined to just block off the hole drainage, and then we get the whole Columbia/Colorado/Snake/Tennessee/Ohio rivers debacle that we have now.
I don't really see hydro, due to it's need for magnitude/isolation/portability issues, as a real viable need for the masses. Solar yes, wind to some extent, but hydro to me is limited.
If we were to put solar panels (both PV and hot water) on more roofs in the US, we could then transition away from fossil fuels slowly and on to other forms, which would provide us a safe amount of diversity and security.
But, like the health care battle, our singular opinions and our desire to be self centered in our thought, are a bit of a limitation for our nation. J.