A little current doesn't mean much. Has no effect on sand bass as far as I can tell but Crappie notice for sure.

This time of year, it hurts the bite because they are trying to spawn and really don’t like the water going up and down.

I really never have issues with gates open on the mainlake the rest of the year. The current May reposition them but they still have to eat

Depending on water clarity, crappie may spawn in 12-18" of water if it's really stained or muddy which is usually the case in the upper ends of lakes with rain. The eggs may take a few days to hatch and the fish sense the water drop and don't want to lay eggs shallow. Hence they pull back and look for deeper water with better clarity for sunlight penetration and warmth. Or they may spawn 3-4 ft deep on other structure away from the bank.

When gates are open big time, it will shut down the bite where you have been catching them no matter what time of year it was. At least that has been my long time ago experience for quite a few years on Ray Hubbard.