[hangsi]

I imagine there are a couple of points that play into this:

1) The good dam spots are occupied, to put it lightly.

2) Hydroelectric dams aren't exactly built to be replaced

3) The technical side of hydroelectric power generation hasn't changed much in recent years; the old dams hold up pretty well for efficiency in taking energy from the water flow.

Hydroelectric dams were great before global warming became an issue.

The effect of all the above points is that a modern dam would be situated in a place either too small or too risky or too troublesome to put one before. With the effects that dams have on the surrounding environment, it's unfeasible to imagine a scenario without government on board.

Given that they must be involved anyway, the state's scarce resources might be better placed in other energy investments than the remaining high growing fruit left on the hydroelectric branch.