No money shall be drawn from the treasury of the City, nor shall any obligation for expenditure of money be incurred, except pursuant to appropriations made by the Council. At the end of each year all unexpended balances of appropriations shall revert to the respective funds from which the same were appropriated, and shall then be subject to future appropriation; but fixed appropriations for longer periods may be made in furtherance of improvements or other objects or work of the City which will not be completed within the current year.
Money appropriated as hereinbefore provided shall not be used for purposes other than those designated in the appropriation ordinance without authority from Council and a certificate of the Finance Director that such money is not encumbered by prior appropriations.