Mich. Comp. Laws § 460.813

Sec. 13. To the extent of ownership by governmental units or joint agencies, projects undertaken pursuant to joint venture agreements authorized by article 2 or joint agency agreements authorized by article 3 of this act are exempt from assessment, collection, and levy of general or special taxes of the state or its political subdivisions. Income produced from municipal ownership in a joint venture or a joint agency shall be exempt from taxation by the state or its political subdivisions. A joint agency corporation formed under article 3 shall not be required to pay taxes upon its income, existence, or franchise. The bonds and notes issued by a municipality in a joint venture agreement or a joint agency corporation, their transfer and the income therefrom, including a profit made on the sale of the bonds or notes, shall be exempt from taxation within this state.