No indebtedness shall be incurred, excepting the indebtedness as may be payable solely from the proceeds of a duly authorized bond issue or from a designated specified source, unless there is a prior appropriation out of which the indebtedness could be paid, as provided by statute. The city shall not become indebted in any manner or for any purpose to an amount in the aggregate exceeding those limitations prescribed by statute.
(1992 Code, § 36.04)