There is created for each project petitioned for under the provisions of this chapter, an augmented drainage board to consist of the members of the drainage board together with the chairman of the board of supervisors and the chairman of the board of county auditors of each county involved. If there is no board of county auditors in any county, then the chairman of the finance committee of the board of supervisors shall act as a member of the augmented drainage board, and if there is neither a board of county auditors nor finance committee, then the chairman of the board of supervisors shall select 1 member of the board of supervisors of his county to act as a member of the augmented drainage board. The chairman and secretary of the drainage board shall act as chairman and secretary, respectively, of the augmented drainage board. The chairman of the board of supervisors and any member of a board of supervisors serving on the augmented drainage board shall receive such compensation, mileage and expenses as shall be provided by the augmented drainage board except that such compensation shall not exceed $25.00 per diem exclusive of mileage and expenses for attendance at augmented drainage board meetings.