Tex. Water Code § 57.251: LEVY OF TAXES ON THE AD VALOREM BASIS.

(a) If a district levies taxes on the ad valorem basis, it shall levy and have assessed and collected taxes on all taxable property in the district.

(b) The taxes must be sufficient to pay the interest on the bonds as it is due, and to raise a sufficient amount to create a sinking fund to redeem and discharge the bonds at maturity.

Acts 1971, 62nd Leg., p. 110, ch. 58, Sec. 1, eff. Aug. 30, 1971. Amended by Acts 1977, 65th Leg., p. 1251, ch. 483, Sec. 10, eff. Aug. 29, 1977; Acts 1979, 66th Leg., p. 2321, ch. 841, Sec. 4(r), eff. Jan. 1, 1982.