Tex. Water Code § 55.204

If the board finds that it is in the best interest of the district and that it is necessary to enable the district to enter into a contract to employ Mexican laborers, it may enter into a written contract to waive in advance the district's immunity from liability in damages for personal injuries and sickness which is proximately caused by torts of the district or negligence of agents or employees of the district and which is suffered by Mexican laborers employed by the district under the terms of the Migrant Labor Agreement of 1951 between the United States and Mexico or any subsequent agreement of a similar nature.