All political subdivisions within the state, upon enactment of this act, are automatically a part of the Kansas mutual aid system. A political subdivision may elect not to participate or to later withdraw from the system by adoption of an appropriate resolution by its governing body declaring that it elects not to participate in the statewide mutual aid system and providing a copy of the resolution to the division. This act does not preclude participating political subdivisions from entering into supplementary agreements with another political subdivision and does not affect any other agreement to which a political subdivision may currently or in the future be a party under other Kansas statutes.