Looks like our mains water is out. Neighbors have water. Is there likely to be anywhere else that mains water comes in to the house, like washing machine etc? How would I know without draining the attic tank?
dont drain tank that all the water you have use carfeully. if neighbours have water thats good. find your stop cock outside house uisce writtin on it small brown hatch in ground that can be opened. try pouring boiling water on it.