Tex. Water Code § 49.314

(a) After the district adopts an order excluding nonirrigated property, a city or other water supply corporation that serves the excluded land with a potable water supply may petition the district to apply to the commission to convert the proportionate irrigation water allocation of the land excluded as nonirrigated property, as determined by the district, from irrigation use to municipal use allocation.

(b) The district shall make such application to the commission within 30 days of the filing of a petition by the city or water supply corporation that serves the land with a potable water supply, provided the city or other water supply corporation pays the district the amount the district estimates will be its reasonable expenses and attorney's fees incurred in the commission conversion proceedings and enters into an agreement with the district setting forth the basis on which the water allocation shall be delivered, or made available, to the city or water supply corporation covering such terms as the entities may agree to, and in the event the parties cannot agree, such dispute shall not be subject to the jurisdiction of the commission, or its successors, under this code but subject to resolution through alternative dispute resolution. In such commission proceeding, the city or water supply corporation shall provide evidence to the commission of the current or projected need within a five year period for the municipal-use water allocation after such conversion as a condition of such conversion of use of the district's water rights from irrigation use to municipal use.