After the adoption of the annual appropriation ordinance, no further appropriations may be made at any other time during that fiscal year, except as provided in this Act, provided that the board of each district may amend such appropriation ordinance from time to time by the same procedure required by this Act for the original adoption of the appropriation ordinance. By a two-thirds vote of all the members constituting the board, the board may make appropriations in excess of those authorized by the appropriation ordinance in order to meet an immediate emergency.
70 ILCS 805/13.4