(1) Except as otherwise provided in section 19, a deviation from the original general appropriations act shall not be made without amending the general appropriations act. Subject to section 16(2), the legislative body of the local unit shall amend the general appropriations act as soon as it becomes apparent that a deviation from the original general appropriations act is necessary and the amount of the deviation can be determined. An amendment shall indicate each intended alteration in the purpose of each appropriation item affected by the amendment. The legislative body may require that the chief administrative officer or fiscal officer provide it with periodic reports on the financial condition of the local unit.

  (2) If, during a fiscal year, it appears to the chief administrative officer or to the legislative body that the actual and probable revenues from taxes and other sources in a fund are less than the estimated revenues, including an available surplus upon which appropriations from the fund were based and the proceeds from bonds or other obligations issued under the fiscal stabilization act, 1981 PA 80, MCL 141.1001 to 141.1011, or the balance of the principal of these bonds or other obligations, the chief administrative officer or fiscal officer shall present to the legislative body recommendations which, if adopted, would prevent expenditures from exceeding available revenues for that current fiscal year. The recommendations shall include proposals for reducing appropriations from the fund for budgetary centers in a manner that would cause the total of appropriations to not be greater than the total of revised estimated revenues of the fund, or proposals for measures necessary to provide revenues sufficient to meet expenditures of the fund, or both. The recommendations shall recognize the requirements of state law and the provisions of collective bargaining agreements.