After the budget has been adopted, no money shall be drawn from the treasury of the City, nor shall any obligation for the expenditure of money be incurred, except pursuant to a budget appropriation. The Commission may transfer any unencumbered appropriation balance or any portion thereof from one department, fund, or agency, to another. The Commission may take additional appropriations during the fiscal year for emergency purposes or for unanticipated and urgently needed purposes, provided, such appropriations shall not exceed the amount by which actual or anticipated revenues of the year are exceeding the revenues as estimated in the budget, or expenses are proving less than anticipated, or a combination thereof. The Commission may make additional appropriations from any available and unencumbered funds, although not budgeted, to relieve an emergency substantially endangering the public health, peace or safety.