30 Tex. Admin. Code § 297.92
The commission may require the alteration or amendment of any contract for the transportation of water if it finds the change is necessary to protect vested rights or prevent the undue loss of water. After the commission is satisfied that all provisions of law and these rules have been complied with and that transportation of the stored water should be authorized, an order will be entered authorizing the use of the watercourse for that purpose and notice shall be made by the commission in accordance with § 295.160 of this title (relating to Notice of Applications To Convey Stored Water). The rate of flow shall be determined by the executive director, and all interested parties will be notified of the rate. An exception to the requirements of this section may be granted by the commission if an emergency condition exists and time does not permit following the procedures herein outlined. Further, the requirements of this section are not applicable if water is being released from upstream storage under order of the commission.
30 Tex. Admin. Code § 297.92