Notwithstanding any contrary provision of law, general or special, any locality may, by ordinance, provide a method to assure continuity in its government, in the event of an enemy attack or other disaster. Such ordinance shall be limited in its effect to a period not exceeding 12 months after any such attack or disaster and shall provide for a method for the resumption of normal governmental authority by the end of the 12-month period.
Va. Code § 15.2-1413