Can we have a small stream that goes around the dam for example?
The salmon ladders In Seattle seem pretty popular with the salmon. Can we not build something like that?
The dams simply need to be removed, starting with the ones that offer minimal value in other dimensions (electricity, water supply, navigable waters, recreation, etc...) until eventually the vast majority are gone and only a few are left to protect important infrastructure that cannot feasibly be moved.
[1] https://www.bkw.ch/fileadmin/bt3_news/MyConvento/2021/10/06/...
There's a pretty crazy company developing this system that actually shoots fish up the damn like those pneumatic canisters bank drive throughs use (or used?). I just remember seeing a video about it but don't know anything more.
Arguably you could instead of damming a river divert a portion of it upstream into a new valley for a lake, leaving the old river alone.