Mich. Comp. Laws § 486.5
When the canal or any of its appurtenances under the control of such association may need to be repaired or rebuilt, the directors of said association may cause the same to be done at the expense of the owners thereof: Provided, That in all cases of permanent improvements of the water-power or appurtenances thereto, as distinguished from repairs, the said directors shall not be authorized to make such improvements, or incur any expense concerning the same, unless first authorized by a vote of the members of said association at a regular or annual meeting thereof, or at a meeting to be called for that purpose: And provided further, That the expense of permanent improvements which are not rendered necessary for the actual preservation or protection of said water-power or its appurtenances shall be assessed and collected in the manner hereinafter provided only upon the members of such association and such owners of water-power not members as shall have consented thereto previous to the making of such improvement.
MCL 486.5