Snake in my Koi Pond !!! Help !!!

Hello, we just recently moved to Georgia. We have a nice backyard pond with 10 Koi in it. They are all about 6". I also got 3 Albino Bullfrog tadpoles. Then this weekend we were SHOCKED to find a 3 foot long water snake in our pond !! It has semi-circular markings...........orange with black outlines, against a sort of beighish backgroung. The horrible thing ATE my tadpoles, AND he might have eaten two of my fish, I'm not certain. We've tried catching him but he's too quick for us. He only shows up at night. HELP !! Is there any Good Samaratan out there who can help me figure out how to get rid of this snake AND keep other snakes from snacking on my Koi ?? ( the snake didn't eat any of the little goldfish I have in the pond ! ) By the way, does anyone have any idea what kind of snake this might be ??

No idea what kind of snake it is but I learned on another thread that there is snake repellent. My local feed store sells it. I lost all my fish to a snake last summer. ;~(

A couple years ago I had a Florida banded water snake in my pond that ate almost all my fish. I only saw him at night. I laid down a net on the surface of the pond and he got caught up in it. then I just picked up the net. Now I keep the pond netted and it keeps the bad guys out.

Sounds like a corn or rat snake, very common in GA and FL.....If you can keep the snakes away, you also don't want bullfrogs of ANY kind, they eat everything in site (small frogs, koi, goldfish)