30 Tex. Admin. Code § 304.43
When a water right is sold or otherwise transferred, the new owner shall promptly inform the executive director of the change of ownership and shall provide the appropriate ownership documents. If a tract of land to which a smaller water right acreage is appurtenant is owned by more than one person in divided interest, the executive director may administratively divide the water right among the owners on a pro rata basis by acreage. If the new ownership record is not complete, the executive director shall inform the alleged owner by letter that ownership documents must be filed within 30 days and approved by the executive director. During a 60-day period following the date of the executive director's letter, the watermaster will honor declarations of intent by the alleged owner in accordance with the water right. After the 60-day period, no declaration of intent will be honored until the executive director notifies the watermaster of the approved change in ownership. Requests for extension for the initial 60-day period must be submitted in writing to the executive director at least five business days prior to the end of the 60-day period. If the extension is granted, the watermaster may honor declarations of intent for the alleged owner; otherwise no declaration of intent from the unverified owner will be honored.
30 Tex. Admin. Code § 304.43