Ala. Code § 16-13-94
Capital outlay warrants issued hereunder shall be payable within the period of usefulness of the improvement or property for which the warrants are issued as estimated by the county or city board of education, which estimate shall be conclusive. In no event shall any warrant issued hereunder be made payable on or after the first of October upon which the special tax pledged for the payment of the warrants last becomes due and payable. All warrants issued hereunder shall be made payable in substantially equal annual instalments of principal and interest beginning in the next fiscal year after their date; provided, that if other warrants issued hereunder or any other law shall be then outstanding constituting a preferred claim against the same tax, all or any part of the maturities of such outstanding warrants may be taken together with the maturities of the new warrants to provide substantially equal instalments of principal and interest; and provided further, that the requirements contained in this sentence shall be directory only and shall not affect the validity of any warrants issued under this article.
Ala. Code § 16-13-94 (1975)