I agree: nobody is fooled by your baseless claims that we can build dams where there's no transportation infrastructure. How does heavy machinery get to the site? How does the concrete get poured?
You insist the dams high in the Sierra Nevada range of California don't exist? You choose a strange hill to die on: anybody can see them in Google Maps satellite view.
They are not generally made of concrete, not being deep enough to need it. Their high pressure is confined in the penstock well downslope.
Earlier you claimed it was trivial to find these inaccessible dams. You took the time to respond to my comment, and could have easily taken the trivial step of finding a few of these dams but curiously chose not to. Or, maybe these dams don't exist.
No such inaccessible dams exist, and if they do they hold an inconsequential amount of hydroelectric energy. Just exercise a modest amount of reasoning: no transportation infrastructure means all work is done by hand and all material transported manually as well.
Pre industrial dams did exist, but they were very shallow and used for irrigation rather than power. Moving enough earth and concrete to make a usable gradient is not possible without heavy machinery.
