(a) A county issuing bonds under this chapter that are secured solely by a pledge of revenues may:
(1) by the bond resolution, authorize the payment of the principal of and premium, if any, and interest on the bonds from the gross revenues of the project; and
(2) impose a direct continuing ad valorem tax under § 9, Article VIII, or § 52, Article III, Texas Constitution, and pledge the tax to pay maintenance and operating expenses of the project and to establish and maintain a reserve fund and a depreciation and replacement fund for the project, as a supplement to the pledge of revenues for those purposes or in lieu of a pledge of revenues, as provided by the bond resolution.
(b) The proceeds of a tax pledged under this section shall be used annually to the extent required by the bond resolution and for the purposes stated in Subsection (a)(2). The county may provide in the resolution that certain or all costs listed in the resolution will be paid by the county from the proceeds of the tax.