Tex. Spec. Dist. Code § 3503.151
(a) Any governmental entity of this state may:
(b) The governmental entity may not use, pledge, or covenant under this section revenue from ad valorem taxes, or the proceeds of bonds paid wholly or partly from ad valorem taxes, unless the use, pledge, or covenant has been approved by the voters of the governmental entity at an election called for the purpose of:
Added by Acts 2005, 79th Leg., Ch. 729 (H.B. 2019), Sec. 1.02, eff. April 1, 2007.