Tex. Water Code § 11.138

(a) The commission may issue temporary permits for beneficial purposes to the extent that they do not interfere with or adversely affect prior appropriations or vested rights on the stream from which water is to be diverted under such temporary permit. The commission may, by appropriate order, authorize any member of the commission to approve and issue temporary permits without notice and hearing if it appears to such issuing party that sufficient water is available at the proposed point of diversion to satisfy the requirements of the temporary permit as well as all existing rights. No temporary permit issued without notice and hearing shall authorize more than 10 acre-feet of water, nor may it be for a term in excess of one year.

(b) The commission may prescribe rules governing notice and procedure for the issuance of temporary permits.

(c) As between temporary permits, the one applied for first has priority.

(d) The commission may not issue a temporary permit for a period exceeding three calendar years.

(e) A temporary permit does not vest in its holder a permanent right to the use of water.

(f) A temporary permit expires and shall be cancelled by the commission in accordance with the terms of the permit.

(g) The commission may prescribe by rule the fees to be paid for issuance of temporary permits, but no fee for issuance or extension of a temporary permit shall exceed $500.