30 Tex. Admin. Code § 297.71
If the commission's records reflect that the amount of water authorized to be appropriated under a water right is not being used, either in whole or in part, the executive director may send an appropriate form to the holder of the water right by which the holder or the holder's authorized agent may request cancellation of the unused portion of the right or the entire right.
Source Note:The provisions of this §297.71 adopted to be effective May 29, 1986, 11 TexReg 2331.