(a) The appropriations made in the appropriation resolution, or any amendment thereto, shall constitute the limit to expenditures for the various purposes and from the several funds of such county for the fiscal year covered by the resolution, and no expenditure shall be made or obligation created in excess of such limitation.

(b) Any resolution presented to the county legislative body in any fiscal year, after the original appropriation resolution has been adopted and the tax rate for the year fixed by the county legislative body, that provides for an appropriation in addition to those made in the original budget appropriation, shall specifically provide by tax levy sufficient revenues, or designate the source of funds to meet expenditures to be made in consequence of such additional appropriation.

(c)

(1) If at any time during the fiscal year it shall become apparent that the revenues of any of the county's funds, together with its unencumbered cash balance at the beginning of such year, will not be sufficient to equal the amount of the original appropriations, it shall be the duty of the director to impound the appropriations from such fund in such amount as shall be necessary to balance such account. Nevertheless, the impoundment power provided by this section shall not apply to the funds appropriated to the offices of trustee, county clerk, assessor of property, clerks of courts, register of deeds or sheriff.

(2) Upon the written approval of the committee, such impounded funds shall be released.