Tex. Water Code § 65.501

The district may issue its bonds or notes for the purpose of purchasing, constructing, acquiring, owning, operating, repairing, improving, or extending any district works, improvements, facilities, plants, equipment, and appliances needed to accomplish the purposes listed in Section 65.012 of this code, including works, improvements, facilities, plants, equipment, and appliances needed to provide a waterworks system, sanitary sewer system, storm sewer system, solid waste disposal system, or to provide for solid waste collection or fire-fighting services and facilities.