No money shall be drawn from the treasury of the township nor shall any obligation for the expenditure of money be incurred, except pursuant to the budget appropriation, or pursuant to any supplemental appropriation which may be made from surplus received. The township board may transfer any unencumbered appropriation balance, or any portion thereof, from 1 fund or agency to another. The balance in any appropriation, which has not been encumbered, at the end of the fiscal year shall revert to the general fund and be reappropriated during the next fiscal year.