43 U.S.C. § 468
The Secretary of the Interior may, in his discretion, withdraw any public notice issued prior to , under section 419 of this title, and he may agree to such modification of water-right applications duly filed prior to , or contracts with water users’ associations and others, entered into prior to , as he may deem advisable, or he may consent to the abrogation of such water-right applications and contracts, and proceed in all respects as if no such notice has been given.