Michigan Compiled Laws, Chapter 324. Natural Resources and Environmental Protection § 324.4304

Sec. 4304. Bonds that are issued and secured by a mortgage on the utility as provided in this part shall not be a general obligation of the local unit of government, but shall be paid only out of revenues received from the service charges as provided in section 4303  1 or from a sale of the property and franchises under a foreclosure of the mortgage. If a service rate is charged, a sufficient portion shall be set aside as a sinking fund for the payment of the interest on the bonds and the principal of the bonds at maturity.