Tex. Water Code § 16.402

(a) Each entity that is required to submit a water conservation plan to the commission under this code shall submit a copy of the plan to the executive administrator.

(b) Each entity that is required to submit a water conservation plan to the executive administrator, board, or commission under this code shall report annually to the executive administrator on the entity's progress in implementing the plan.

(c) The executive administrator shall review each water conservation plan and annual report to determine compliance with the minimum requirements established by Section 16.4021 and the submission deadlines developed under Subsection (e) of this section.

(d) The board may notify the commission if the board determines that an entity has violated this section or a rule adopted under this section. Notwithstanding Section 7.051(b), a violation of this section or of a rule adopted under this section is enforceable in the manner provided by Chapter 7 for a violation of a provision of this code within the commission's jurisdiction or of a rule adopted by the commission under a provision of this code within the commission's jurisdiction.

(e) The board and commission jointly shall adopt rules:

(1) identifying the minimum requirements and submission deadlines for the annual reports required by Subsection (b);

(2) requiring the methodology and guidance for calculating water use and conservation developed under Section 16.403 to be used in the reports required by Subsection (b); and

(3) providing for the enforcement of this section and rules adopted under this section.

(f) At a minimum, rules adopted under Subsection (e)(2) must require an entity to report the most detailed level of municipal water use data currently available to the entity. The board and commission may not adopt a rule that requires an entity to report municipal water use data that is more detailed than the entity's billing system is capable of producing.