Mich. Comp. Laws § 117.4j

Sec. 4-j. Each city may in its charter provide: (1) For the establishment of any department that it may deem necessary for the general welfare of the city, and for the separate incorporation thereof: Provided, however, That these provisions shall not be construed to extend to and include public schools; (2) For altering, amending or repealing any special act affecting any municipal concerns or existing municipal department, but the department in control of the public schools shall not be construed to be a municipal department; (3) For the exercise of all municipal powers in the management and control of municipal property and in the administration of the municipal government, whether such powers be expressly enumerated or not; for any act to advance the interests of the city, the good government and prosperity of the municipality and its inhabitants and through its regularly constituted authority to pass all laws and ordinances relating to its municipal concerns subject to the constitution and general laws of this state.