In order to promote efficiency and coordination in the overall planning by the various governmental entities having an interest within the geographical territory embraced within the planning authorization granted to the county within this act, and to encourage the elimination of duplication of effort in planning for such areas, the board of county commissioners may initiate joint efforts with other governmental entities including, but not limited to, cities, townships, fire districts, water districts and wastewater districts and the planning commission, with the approval of the board of county commissioners, is authorized to initiate and jointly prepare, in whole or in part, any plans or programs developed as a part of such joint or cooperative effort. Such plans or programs shall be considered for recommendation by the planning commission and adoption by the board of county commissioners in the same manner and with the same requirements as specified elsewhere in this act for adoption of the comprehensive plan.

The board of county commissioners shall approve any intergovernmental agreement or other formal document that shall outline the extent of common interest, the duration of the agreement, the role of the various parties involved, the desired results of such joint or cooperative effort and any other matter deemed pertinent by the parties involved. Such agreements may be made by the county and one or more other governmental entities as may choose to participate.