At any regular or special meeting, the board by a four-fifths vote may make available for appropriation any of the following fund balances for which the board has authority:
(a) Restricted, committed, assigned, and unassigned fund balances, excluding the general reserves and nonspendable fund balance.
(b) Amounts that are either in excess of anticipated amounts or not specifically set forth in the budget derived from any actual or anticipated increases in financing sources.