3 feet deep in combination with a deicer of some sort should be fine for overwintering depending on how cold it gets. These last couple years have been pretty mild. In the past when winters have been harsher I've lost fish in a 1300 gallon 3.5' deep pond that had a deicer. Got cold enough that the ice broke the deicer.
Not sure on the regulations, those are something that would likely differ by town/city/county/etc.
Not sure on the regulations, those are something that would likely differ by town/city/county/etc.
