Texas Government Code - GOV'T § 1506.057. Interest and Sinking Fund Tax

(a) A municipality may not issue bonds under this subchapter creating a debt against the municipality or an improvement district unless the municipality provides for the imposition of an annual ad valorem tax on property in the improvement district at a rate sufficient to:

(b) The rate of the tax may not exceed 50 cents on the $100 valuation of property taxable by the municipality.

(c) The tax is in addition to other taxes imposed by the municipality or authorized to be imposed by the municipal charter.