Mich. Comp. Laws § 280.381
Whenever the commissioner of any county shall receive a petition asking for the laying out, construction, cleaning out, deepening or widening of any drain, or a petition asking proceedings by virtue of which any assessment upon lands for benefits received would result, wherein such commissioner shall be interested by reason of himself, wife or child, owning lands that would be liable to an assessment for benefits upon the work or proceeding proposed to be done or had, and in cases where such commissioner may be otherwise disqualified to act in the making of apportionment of benefits, such commissioner shall file a copy of such petition with the judge of probate of the county, together with a statement signed by him, showing that he is disqualified to act in making such apportionment of benefits.
MCL 280.381