Mich. Comp. Laws § 280.241
No warrant or drain order for the payment of any part of such drain contract shall be drawn until the work has been inspected and approved as herein provided. The commissioner may inspect and approve any tile or open drain, or he may designate any competent surveyor or engineer to make such inspection, but where the construction exceeds $3,000.00, the commissioner shall designate a competent surveyor or engineer to make the inspection. Any person making such inspection shall see that the specifications in the contract are fully complied with, and if the work is not in accordance with the contract, the commissioner shall immediately notify the contractor thereof. If the work so inspected shall conform to the contract, the person making the inspection shall certify in writing to that fact and an order of approval shall thereupon be entered by the commissioner in his drain record, and notice of the approval be given the contractor. The commissioner may issue warrants or orders on the fund of any drain not exceeding 90% of the amount earned on any contract after the certificate of inspection and the order of approval is entered as herein provided. The payment of the final 10% or any portion thereof on any contract may be made after the certificate of inspection is made attesting to the completion and is filed in the office of the commissioner.
MCL 280.241