Bruce wrote:

Why can't they create a lock setup for the canal?

They already have locks. How can they filter fish out? It's not
that simple.

Where are these locks?

They have electrification equipment on the Chicago river - why not put
them in the locks (if these locks really do exist).

When a ship is in the lock and the lake-side lock door is closed, you
turn on the juice force any fish out of the lock and into the river-side
part of the lock, then you close the river-side lock door and open the
lake-side door to let the ship out into the lake, then you close the
lake-side door.

If you always keep the electicity turned on inside the lock chamber,
you'll see if any fish are in there jumping around and deal with them
one way or another.

Throw a bucket of salt into the chamber once per hour to increase
electrical conductivity to really make it nasty for them.