It is the purpose of this chapter to permit local governmental units to make the most efficient use of their powers by enabling them to cooperate with other localities on a basis of mutual advantage and thereby to provide services and facilities in a manner and pursuant to forms of governmental organization that will accord best with geographic, economic, population and other factors influencing the needs and development of local communities.

Joint operations by municipal corporations and political subdivisions, deposit and control of funds: RCW 43.09.285.