Tex. Water Code § 36.322

If the district has bonds, notes, or other obligations outstanding or bonds payable in whole or in part from taxation that have been voted but are unissued, the petitioner shall assume its share of the outstanding bonds, notes, or other obligations and any voted but unissued tax bonds of the district, and the property shall be assessed an ad valorem tax at the same rate as that set for the existing district to pay for outstanding bonds and for the maintenance and operation of the district.