43 C.F.R. § 2524.4
If, after investigation the irrigation project has been or may be abandoned by the Government, the time for compliance with the law by the entryman shall begin to run from the date of notice of such abandonment of the project and of the restoration to the public domain of the lands which had been withdrawn in connection with the project. If, however, the reclamation project is carried to completion by the Government and a water supply has been made available for the land embraced in such desert-land entry, the entryman must, if he depends on the Government's project for his water supply, comply with all provisions of the reclamation law, and must under the Act of June 6, 1930 (46 Stat. 502; 43 U.S.C. 448 ), relinquish or assign in not less than 2 years after notice all the land embraced in his entry in excess of one farm unit, and upon making final proof and complying with the regulations of the Department applicable to the remainder of the irrigable land of the project and with the terms of payment prescribed in the reclamation law, he shall be entitled to patent as to such retained farm unit, and final water-right certificate containing lien as provided for by the Act of August 9, 1912 (37 Stat. 265; 43 U.S.C. 541-546 ), Act of August 26, 1912 (37 Stat. 610; 43 U.S.C. 547 ), and the Act of February 15, 1917 (39 Stat. 920; 43 U.S.C. 541 ), or to patent without a lien if provision therefor shall have been made as provided for by the Act of May 15, 1922 (42 Stat. 541; 43 U.S.C. 511-513 ).
43 C.F.R. §2524.4