Tex. Utilities Code § 53.003: JUST AND REASONABLE RATES.

(a) The commission shall ensure that each rate a public utility or two or more public utilities jointly make, demand, or receive is just and reasonable.

(b) A rate may not be unreasonably preferential, prejudicial, or discriminatory but must be sufficient, equitable, and consistent in application to each class of consumer.

(c) A public utility may not:

(1) grant an unreasonable preference or advantage concerning rates to a person in a classification;

(2) subject a person in a classification to an unreasonable prejudice or disadvantage concerning rates; or

(3) establish or maintain an unreasonable difference concerning rates between localities or between classes of service.

(d) In establishing a public utility's rates, the commission may treat as a single class two or more municipalities that a public utility serves if the commission considers that treatment to be appropriate.

Acts 1997, 75th Leg., ch. 166, Sec. 1, eff. Sept. 1, 1997.