Tex. Gov't Code § 1509.111
(b) The municipality shall impose and collect pledged charges in an amount that will be at least sufficient, with any other pledged resources, to provide for the payment of:
(2) to the extent required by the ordinance authorizing the issuance of the bonds:
Added by Acts 1999, 76th Leg., ch. 227, Sec. 1, eff. Sept. 1, 1999.