If there is an emergency, or if it is necessary to do emergency work to prepare for national or local defense, the district board may pass a resolution by a four-fifths vote of its members declaring that the public interest and necessity demand the immediate expenditure of district funds to safeguard life, health, or property. Upon adoption of the resolution, it may expend any sum required in the emergency without complying with this article. If notice for bids to let contracts will not be given, the board shall also comply with Chapter 2.5 (commencing with Section 22050).