The approved final budget governs the expenditures of the county during the fiscal year. Expenses may not be incurred in excess of those shown in the approved final budget. The budget may be revised if the county commissioners prepare and submit a proposed budget amendment to the budget committee for approval. The amended budget becomes effective only after the budget committee has approved the amendment. A report of an approval of a budget amendment must be transmitted to the State Auditor within 15 days of that approval by the budget committee.   [PL 1991, c. 257 (NEW).]