On the Diamond Creek claim when the water freezes over message is present water does freeze in relation to it not being able to be pumped ibut.....
The river can be walked on as if it is frozen but it looks unfrozen and you can see the visual ripples and effects of wind on it.
The water in the swamp and abandoned mine is similar but you cant walk on it and you still enter into it as if it was not frozen.
Playing on series X
#Water not looking frozen
quaint vortex
Additional info.
Hoses and or equipment in abandoned mine will sit on top of water when placed when temp is low enough to freeze.
They however do not in the swamp and they always sink in water.
All purely aesthetic issues however and gameplay is not negatively effected when water should be frozen and unusable all sources can not be used.
In regards to the pump-house that drains the swamp, it can still be used to drain the swamp and the swamp refills if it is turned off.