Tex. Water Code § 13.084

The governing body of any municipality or the commissioners court of an affected county shall have the right to select and engage rate consultants, accountants, auditors, attorneys, engineers, or any combination of these experts to conduct investigations, present evidence, advise and represent the governing body, and assist with litigation on water and sewer utility ratemaking proceedings. The water and sewer utility engaged in those proceedings shall be required to reimburse the governing body or the commissioners court for the reasonable costs of those services and shall be allowed to recover those expenses through its rates with interest during the period of recovery.