Auggie, I assume youre being facetious there. The environment and the beaver managed to do quite well before the dept of Natural Resources and your state came into existence.
Beavers do actually enhance the environment by flooding forested areas
which gradually fill in and become open meadows and bring other wildlife in. Lakes do have a certain life cycle and rivers do change direction.

on the topic of streams and micro power generation - I happened to talk to a couple of engineer friends of mine on the weekend and their view was that in order to do any significant power generation you need a fairly large volume of water and at least a 10ft drop. (There is a formula - for power generation) Unless its a really large and fast stream though its unlikely you will get enough to power everything in a household (ie a stove or a dryer have a much larger load than your lights)

having said that though I still think its a great idea to have some auxiliary power generated by stream - and if leftover sell back to utilitity - I know they already do that in some European countries.

I think future power generation will likely be a combination of many different forms of energy be it, hydro, solar wind, tidal geothermal
nuclear -