Beer Keg cooler using creek

We're selling our Airstream which formerly housed two beer kegs (so we didn't have to purchase/run an additional refrigerator). In the interest in keeping our utility costs low (rates are very high here in NC), we'd like to explore using our creek to cool the keg. We're in zone 7a/6b so we do get some 10 degree days in the winter. The creek never freezes over, but we do see some ice forming along branches. The creek runs year round, but can get as low as 6" deep at times. There's a nice shady spot under some rhododendrons.

We're trying to think of a way to use the nice cool running water to cool the keg, but not have it freeze on the top. We imagine building some sort of bridge structure with holes for each keg that would secure them from tipping over in periods of high waters. We're thinking we might have to dig a hole and line with bricks to immerse the keg deeper, but that's going to be challenging with a fast running creek.

And then preventing freezing in the winter months...

Any thoughts?

What temperature do you need and what is the creek temperature?
You could use a heat pump and create hot water as well from the same stream.

maybe a photo or two?

the temperature of the creek is about 42 degrees F so it's actually perfect for passive cooling. We're not trying to use electricity b/c otherwise, we'd just get a refrigerator.

i'll try to get a photo up soon.

Yes - pictures would help! My thoughts are along the line of local "floating docks" - the ability to go up and down with water level without human intervention - is normally accomplished by a large post sunk into the bottom of the ocean, with a frame around it that can slide up and down. I'm not that knowledgeable about "Beer Keg Coolers" so please elaborate:
1) is the goal to keep the whole cooler under water or only the bottom of it?
2) if you're worried about occasional freezing weather, is it light enough to be moved elsewhere during high-risk periods?
3) how important is it to keep it upright?
4) how buoyant is it? - Is the issue going to be keeping it under, rather than keeping the top dry? The type of cooler we have would float like a cork. I suspect you're going to want some sort of anchor on it either way.
5) Is it sealed well enough not to attract vermin?

Do you have enough fall that you could pipe it over into a spring box? Basically a box on shore do you have a constant height of water over the kegs.