Tex. Water Code § 16.404

The commission and the board, as appropriate, shall adopt rules and standards as necessary to implement this subchapter. At a minimum, the rules adopted under this subchapter must require an entity to report the most detailed level of water use data currently available to the entity. The commission may not adopt a rule that requires an entity to report water use data that is more detailed than the entity's billing system is capable of producing. The rules may require that billing systems purchased after September 1, 2011, be capable of reporting detailed water use data described in this subchapter.