Mich. Comp. Laws § 123.744
A county operating under this act, by action of its board of public works, may acquire property for a water supply, an erosion control system, a sewage disposal or a refuse system or for lake improvements by purchase, construction, lease, gift, devise, or condemnation, either within or without its corporate limits and may hold, manage, control, sell, exchange, or lease the property. Real estate shall not be disposed of without the approval of the county board of commissioners. For the purpose of condemnation it may proceed as provided in chapter 3. If the property acquired by a county is already being used for water supply, sewage or refuse disposal or lake improvement purposes, such use may be continued by the county without a resolution of or contract with the municipality in which the property is located.
MCL 123.744