70 ILCS 810/20
The president shall preside at all meetings of the board and be the executive officer of the district. He shall sign all ordinances, resolutions and other papers necessary to be signed and he or his designee shall execute all contracts entered into by the district and perform other duties as may be prescribed by ordinance. He may veto any ordinance and any orders, resolutions and actions, or any items therein contained, of the board which provide for the purchase of real estate, or for the construction of improvements within the preserves of the district. Such veto shall be filed with the secretary of the board within 5 days after the passage of the ordinance, order, resolution or action and when so vetoed the ordinance, order, resolution or action or any item therein contained is not effective unless it is again passed by two-thirds vote of all the members of the board. The president may vote in the same manner as the other members of the board. In the temporary absence or inability of the president, the members of the board may elect from their own number a president, pro tem.
The "Yeas" and "Nays" shall be taken, and entered on the journal of the board's proceedings, upon the passage of all ordinances and all proposals to create any liability, or for the expenditure or appropriation of money. The concurrence of a majority of all the members appointed to the board is necessary to the passage of any such ordinance or proposal. In all other cases the "Yeas" and "Nays" shall be taken at the request of any member of the board and shall be entered on the journal of the board's proceedings.
70 ILCS 810/20