Michigan Compiled Laws, Chapter 120. Port Districts § 120.120

Sec. 20. Any 1 or more municipalities or other public corporations, either within or without an authority, may contract for the use of port facilities from an authority operating under this act. The charges specified in a contract shall be subject to increase by the authority at any time in order to provide funds to meet the obligations of the project involved. A contract authorized pursuant to this section shall be for a period of not more than 50 years.