Ala. Code § 41-10-64
For the purpose of providing funds for the payment of the costs and expenses necessary to accomplish the purpose of this authority and for the payment of the principal of and interest on any bonds issued by the authority under the provisions of this article, there is hereby created and irrevocably pledged to the payment of such obligations a special and continuing trust fund which shall consist of all revenues, receipts and income from rents contracted for and received by the authority and all revenues, receipts and income received by the authority from any other source whatsoever.
There shall be created within said special and continuing trust fund a reserve fund account of said authority in the State Treasury, in which shall be placed as a trust fund and held separate and apart from all other moneys of the state or of the authority, any moneys left over after the completion of the acquisition, erection and construction of the facilities of the authority and the payment of all costs in connection therewith and in connection with the issuance of the bonds and all excess rentals and other surplus income after the payment of all annual charges and expenses of operation in each fiscal year, including principal and interest. Said reserve fund shall be held by the State Treasurer in trust for the authority and the holders of its bonds and may be invested only in securities which are either direct obligations of the United States of America or fully guaranteed as to principal and interest by the United States of America. Said reserve fund shall be used by the State Treasurer to pay, when due and payable, any installment of principal and interest or both on the outstanding bonds of the authority for which said fund was created which cannot be paid out of current revenues or other moneys of the authority. Said funds shall not be diverted or used for any other purpose.
There shall be created in said special and continuing trust fund an account thereof in which shall be deposited, segregated and held only the amounts reasonably estimated to be necessary for the maintenance, operation and upkeep of the facilities of the authority, with all excess moneys at the end of each fiscal year being transferred to the reserve fund, and the authority is authorized and is hereby directed to pay out of such account in the special and continuing trust fund all reasonable expenses of the maintenance, operation and upkeep of the facilities of the authority.
Ala. Code § 41-10-64 (1975)