In addition to the other powers and duties imposed upon them by the Charter, the board of each department having control over its own special funds shall:
(a) provide suitable quarters, equipment and supplies for the department, create the necessary positions in the department, authorize the necessary deputies, assistants and employees and fix their duties, and may require bonds of any or all the department’s employees for the faithful performance of their duties; and
(b) prior to the beginning of each fiscal year, adopt an annual departmental budget and make an annual department budget appropriation, covering the anticipated revenues and expenditures of the department. The departmental budget shall conform as far as practicable, to the forms and times provided in Article III for the general City budget. Each departmental budget shall contain a sum to be known as the Unappropriated Balance, which sum shall be available for appropriation by the board later in the ensuing fiscal year to meet contingencies as they may arise. A copy of the budget when adopted, and of every resolution subsequently adopted making appropriation from the Unappropriated Balance shall promptly be filed with the Mayor and Controller. No expenditure shall be made or financial obligations incurred by the department except as authorized by the annual departmental budget appropriation, or appropriations made after the adoption of the annual budget, or as otherwise provided in the Charter.