Mich. Comp. Laws § 280.518

Sec. 518. Meetings of the drainage board, or of the augmented drainage board, may be called by the chairperson or 2 members of the board, on notice sent by registered mail to each member. The notice shall be mailed not less than 10 days before the time of the meeting. A majority of the members of the board shall constitute a quorum for the transaction of business, but a lesser number may adjourn from time to time. A meeting may be adjourned from time to time. Unless otherwise provided herein, an action shall not be taken by either of the boards except by a majority vote of its members. All orders issued by either the drainage board, or the augmented drainage board, shall be signed by the chairperson and secretary.