Frozen floodwater

[BDG]

Water and gas mains should be deep enough not to be troubled, but their would be a lot of heave that would destroy paths and roads, winter crops lost, lot of damage to trees, disruption of water flows so any rain or melt would flow over the land, deep cooling of the ground so it would take a lot longer to warm up for crops in spring, death of pasture, but that is all worst case.

The ground holds enough heat not to freeze up too bad in the UK.