Mich. Comp. Laws § 123.961g
The ordinance or resolution authorizing the bonds shall establish a bond and interest redemption fund into which shall be paid all cash rentals required to be paid by the incorporating unit or units under the contract of lease which are pledged for the payment of bonds issued under this act and such other sums as shall be required by the ordinance or resolution to be paid therein and shall establish such other funds and accounts and provide for deposits thereto as the governing body shall prescribe in the ordinance or resolution authorizing the bonds. All moneys in the funds and accounts established by the ordinance or resolution authorizing the bonds, including the proceeds of sale of the bonds, shall be deposited with 1 or more banks designated by the commission. Moneys in the bond and interest redemption fund shall be kept in a separate depository account kept with 1 or more of the banks or trust companies where the principal of and interest on the bonds are payable. Moneys in the several funds and accounts may be invested in United States government obligations or obligations the principal of and interest on which are guaranteed by the United States government or in interest bearing time deposits as shall be determined by the commission in the ordinance or resolution authorizing the bonds.
MCL 123.961g