Whenever it shall be deemed necessary by the county commission of any county in this state to pay any debt or liability now existing against any county incurred for the erection, construction, or maintenance of the necessary public buildings or bridges or that may hereafter be created for the erection of necessary public buildings, bridges, or roads, such court shall have the power and authority to levy and collect a special tax upon the taxable property of such county, not to exceed in one year one fourth of one percent for such purposes; and such tax, when collected, shall be applied exclusively for the purposes for which the same was so levied and collected.
Ala. Code § 11-14-16 (1975)