Texas Water Code, Chapter 13, Subchapter E, §13.1394 and §13.1395, prescribes the duties of the commission relating to standards for emergency operations of affected utilities. The statutes require that the commission ensure that affected utilities provide water service as soon as safe and practicable during an extended power outage. This subchapter sets forth requirements and implementation of emergency operation planning of affected utilities as defined in this subchapter. Public water systems must comply with the emergency operations requirements as defined in Chapter 290, Subchapter D of this title (relating to Rules and Regulations for Public Water Systems).