Townships have constitutional and statutory authority to enter into contracts for governmental functions and services with other governmental units, as well as statutory authority to join with other governmental units to form statutory bodies such as authorities to provide governmental functions and services.
For example, townships may join with other units to provide fire protection in many ways, from a simple mutual aid agreement to a multi-unit fire authority.
There are numerous statutes that authorize general or specific intergovernmental cooperation powers to townships; a few are listed here.
Article VII § 28 of the Michigan Constitution of 1963 [Excerpt]:
"The legislature by general law shall authorize two or more counties, townships, cities, villages or districts, or any combination thereof among other things to: enter into contractual undertakings or agreements with one another or with the state or with any combination thereof for the joint administration of any of the functions or powers which each would have the power to perform separately; share the costs and responsibilities of functions and services with one another or with the state or with any combination thereof which each would have the power to perform separately; transfer functions or responsibilities to one another or any combination thereof upon the consent of each unit involved; cooperate with one another and with state government; lend their credit to one another or any combination thereof as provided by law in connection with any authorized publicly owned undertaking."