Usually this is due to a water main break in your neighborhood. The Utilities Division personnel must turn off the water to repair the line. It is only off as long as is required to repair the pipes. Inquiries about the status of main breaks should be made by calling the Public Works Department at (603) 890-2150.
We cannot feasibly notify everyone door to door that we need to turn the water off in an emergency like this. We can assure you that it is only done if necessary and will be restored as soon as possible.