Big flatheads are commonly caught at night in very shallow water.
And of course CCs will hit the surface.
Lynyrd, If you put some big flatheads in your pond, they will eat every fish that fits in their mouth. So like Esshup says, you better have the pond full of fish for them to eat.
There is no doubt that flatheads will eat anything they can fit in their mouth. I once cleaned a 27 lb flathead that had the tail of a 7 lb blue cat sticking out of its mouth. Without the blue he only weighed 20! I don't know if he would have ever digested what he swallowed or not.
I am not planning on stocking bass, so the flatheads competing with them won't be a problem. I do want channel cats and blues. I also like the idea of crappie, both as supper and as forage fish for the flatheads. Green sunfish (what we locally call slicks, or slick jacks) are native to this area and pretty prolific. I intend to cultivate a healthy population of them.
So, what I am HOPING for is a 13 acre lake that will produce flatheads, channel cats, blue cats, and crappie. The lake will be about 150 yds wide at the dam and about 600 yds long. Roughly half will average 12' deep, with the deepest part near the dam bottoming out at 25 feet. There will be about 3 acres of water in the shallow end that will be no more than 4 feet deep. A live creek will feed the lake about 10 months out of the year, so water levels won't vary much.