I did a quick search but couldn't find anything. I know there are some pictures though.
If you have the eqipment I would make the spillway wider. That way the water would be shallower and you would probably only lose the Fatheads.
Most pond fish don't like current so they will probably just hunker down. Grass Carp are one fish that do like current and will go downstream if you don't have a blocking net. You would probably only lose the small fish that are not strong enough to outswim the current.
