Tex. Water Code § 55.038

(a) If the proposition to issue notes carries, the board of directors shall issue notes of the district, in an amount not to exceed four percent of the cost of the proposed improvements, for the purpose of creating a fund to pay the cost of organizing the district and the cost of all surveys, investigations, engineering, issuance of bonds, making and filing of maps and reports, legal expenses, and all other costs and expenses authorized or made necessary by the provisions of this chapter. The board shall sell the notes or exchange them in payment of the costs and expenses.

(b) The notes shall be secured by the levy, assessment, and collection of taxes as provided for payment of bonds. The notes shall be paid out of the proceeds of the district's bonds when they are issued and sold. If the bond election fails to carry, then the notes shall be paid out of the tax revenue.