Presently, our local PUD(through the Bonneville Agency) may develop a mini-hydro dam on the south fork of the Skykomish River at SunSet Falls. Quite a bit of local & environmental opposition, tho.
Another spot further up river could have a small amount of hydro electric development. However, the falls there is very scenic as is the Sunset Falls. Altho very scenic, it is immediately bordered by Highway 2 crossing the Cascade Mountains. Other spots even further up-river could supply power, but right in very scenic areas, AND right along Highway 2, also.
Already, the PUD has a good sized earthen hydro-dam on the outlet from our Spada Lake watershed, supplying 5%-10% of our county's electric needs.