Texas Water Code - WATER § 54.503. Manner of Repayment of Bonds

(1) from the levy and collection of ad valorem taxes on all taxable property within the district;

(2) by pledging all or any part of the designated revenues to result from the ownership or operation of the district's works, improvements, facilities, plants, equipment, and appliances or under specific contracts for the period of time the board determines;

(3) by pledging all or part of any funds or revenues available to the district;  or

(4) a combination of the sources set forth in Subdivisions (1), (2), and (3) of this section.