If at any time after the issuance of any of the bonds it shall become apparent to the commissioner of administration that the funds available in the state revenue fund will not be sufficient for the payment of the sinking fund and interest on outstanding obligations of the state and for the purpose of public education and the principal and interest maturing and accruing on the bonds during the next succeeding fiscal year, a direct tax shall be levied upon all taxable tangible property in the state for the payment of the bonds and the interest that will accrue thereon. In such event, it shall be the duty of the commissioner of administration annually, on or before the first day of July, to determine the rate of taxation necessary to be levied upon all taxable tangible property within the state to raise the amount of money needed to pay the principal of and interest on the bonds maturing and accruing in the next succeeding fiscal year, taking into consideration available funds, delinquencies and costs of collection. The commissioner of administration shall annually certify the rate of taxation so determined to the county clerk of each county and to the comptroller or other officer in the city of St. Louis whose duty it shall be to make up and certify the tax books wherein are extended the ad valorem state taxes. It shall be the duty of the county clerks and of the comptroller or other proper officer in the city of St. Louis to extend upon the tax book the taxes to be collected and to certify the same to the collectors of the revenue of their respective counties and of the city of St. Louis, who shall collect such taxes at the same time and in the same manner and by the same means as are now or may hereafter be provided by law for the collection of state and county taxes, and to pay the same into the state treasury for the credit of the water pollution control bond and interest fund.