Tex. Water Code § 36.416

(a) If a district contracts with the State Office of Administrative Hearings to conduct a hearing, the hearing shall be conducted as provided by Subchapters C, D, and F, Chapter 2001, Government Code. The district may adopt rules for a hearing conducted under this section that are consistent with the procedural rules of the State Office of Administrative Hearings.

(b) If requested by the applicant or other party to a contested case, a district shall contract with the State Office of Administrative Hearings to conduct the hearing. If the district does not prescribe a deadline by rule, the applicant or other party must request the hearing before the State Office of Administrative Hearings not later than the 14th day before the date the evidentiary hearing is scheduled to begin. The hearing must be held in Travis County or at a location described by Section 36.403(c). The district shall choose the location.

(c) The party requesting the hearing before the State Office of Administrative Hearings shall pay all costs associated with the contract for the hearing and shall deposit with the district an amount sufficient to pay the contract amount before the hearing begins. At the conclusion of the hearing, the district shall refund any excess money to the paying party. All other costs may be assessed as authorized by this chapter or district rules.

(d) An administrative law judge who conducts a contested case hearing shall consider applicable district rules or policies in conducting the hearing, but the district deciding the case may not supervise the administrative law judge.

(e) A district shall provide the administrative law judge with a written statement of applicable rules or policies.

(f) A district may not attempt to influence the finding of facts or the administrative law judge's application of the law in a contested case except by proper evidence and legal argument.