The Council shall provide by resolution appropriate methods and safeguards for the expenditure of funds and the payment of obligations so as to insure that no payment shall be made or obligation incurred without an appropriation having first been approved by the Council, without a sufficient unencumbered balance in the appropriation, or without insuring that sufficient funds are or will be available to cover the claim or meet the obligation when it becomes due and payable. However, except where prohibited by law, nothing in this Charter shall be construed to prevent the making or authorizing of payments or the making of contracts for capital improvements to be financed wholly or partly by the issuance of bonds, or to prevent the making of any contract or lease providing for payments beyond the end of the fiscal year. Any such action must be approved by ordinance.