Tex. Water Code § 51.415

After the vote is canvassed and the results are declared to be favorable to the proposition, the board shall make and enter an order directing the issuance of the bonds or the execution of a contract with the United States. The bonds or contract shall be in a sufficient amount to pay for the improvements together with all necessary incidental expenses, but the amount may not be more than the amount specified in the election order and notice of election.