Mich. Comp. Laws § 280.278
If bonds or notes are issued and sold by the commissioner, installments of the drain taxes shall bear interest at a rate that is not greater than 1% per annum more than the average rate of interest on the bonds or notes from the date of the preparation of the assessment roll until due. The bonds or notes may provide, if the commissioner so determines, for the payment of interest semiannually. The installments and the interest shall, as collected, be paid into the county treasury and placed to the credit of the fund of the drain, to be used solely for the payment of bonds or notes as they mature or are subject to mandatory redemption. Money collected in anticipation of the payment of the bonds or notes shall be deposited by the county treasurer in a bank or banks to be designated by the board of commissioners of the county and the interest received shall belong to the fund. Bonds or notes issued and sold by the commissioner shall bear interest at not to exceed the rate specified in the revised municipal finance act, 2001 PA 34, MCL 141.2101 to 141.2821.
MCL 280.278