We do have the same issue here in Europe, albeit at a smaller scale. If the old dams can be re-purposed and brought back to use, then that would be a nice compromise.
Some old dams and sluices are beyond repair, though. In those cases it's better to just restore the rivers as far as possible.
That's a fair point. In North America, one of the other things that we should probably consider is the American beaver, which can help with this sort of thing naturally, if they're allowed to. Their activity needs a little management to prevent them from disrupting existing settlements, but compared to effect they had before trappers started in on them, it seems like there's might be some room for a natural solution that checks both boxes to a degree.
Edit: Just kidding, I hadn't realized that the Eurasian beaver had been reintroduced to so much of its original range. Looks like it's not just something for North America.
Yeah, and here in Finland we have North American Beavers too, since someone decided to introduce them in the 30's. They have a somewhat devastating effect on the local forests...
Some old dams and sluices are beyond repair, though. In those cases it's better to just restore the rivers as far as possible.