What should I do about damaged electrical conduit?
As a minimum, you really ought to test the cable (or have it tested by a professional) to ensure that it hasn't been damaged. You really don't want to find that there is a problem when a fault occurs at a later date.

If there is no physical damage to the cable, you should at least seal the conduit to prevent further ingress of water, for example wrap the damaged area with self-amalgamating tape.