No payment shall be made or obligation incurred against any allotment or appropriation except in accordance with appropriations duly made and unless the mayor or the mayor’s designee first certifies that there is a sufficient unencumbered balance in such allotment or appropriation and that sufficient funds therefrom are or will be available to cover the claim or meet the obligation when it becomes due and payable. Any authorization of payment or incurring of obligation in violation of the provisions of this charter shall be void and any payments made illegal. A violation of this provision shall be cause for removal of any officer who knowingly authorized or made such payment or incurred such obligation. Such officer may also be liable to the city for any amount so paid. Except where prohibited by law, however, nothing in this charter shall be construed to prevent the making or authorizing of payments or 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, but only if such action is made or approved by ordinance.