La. Stat. tit. 33 § 4124
It shall be the duty of the Council of the City of New Orleans, or its successor, as the governing body of said City of New Orleans, to levy and collect for the year 1967, and annually thereafter for a term of fifty (50) years, a special ad valorem tax of three (3) mills on the dollar, as adjusted in accordance with the provisions of the Louisiana Constitution of 1974, upon all taxable property, real, personal and mixed, in the City of New Orleans. The proceeds of said tax shall be paid over to the Board of Liquidation, City Debt, day by day as the same is collected by the proper officials of the City of New Orleans and such proceeds shall be used solely and exclusively for the operation and maintenance of the drainage system of the City of New Orleans; and for the construction and extension of said drainage system, excluding subsurface drainage systems and their appurtenances; and shall be deposited with the fiscal agent banks of the Board of Liquidation, City Debt, to the credit of a special fund called "Drainage System Fund". The Board of Liquidation, City Debt, may, in its discretion, invest any of the proceeds of said special tax in such investments as it is authorized by law to make whenever an officer designated by the Sewerage and Water Board of New Orleans requests the investment of such funds by the Board of Liquidation, City Debt. All disbursements made by the Sewerage and Water Board out of the proceeds of said fund shall be made in the form of warrants or drafts on the Board of Liquidation, City Debt, setting forth the amounts thereof, the persons to whom payable, and the purpose for which the payment is made; and the Board of Liquidation, City Debt, is charged with the duty of taking care that no irregular or improper or unlawful payments are made out of said special fund. The Board of Liquidation, City Debt, as now organized and created and with the powers, duties and functions prescribed by existing laws and by this amendment shall be continued as long as said special tax is levied and collected under this amendment. The provisions hereof are self-operative and the City of New Orleans and the several boards and bodies herein referred to shall carry the same into effect.
La. R.S. § 33:4124