(a) The States are allowed 10 years from the date of the signing of the contract by the Secretary in which to cause the lands to be reclaimed. If the State fails in this, the State Director may, in his discretion, extend the period for up to 5 years, or may restore the lands to the public domain at the end of the 10 years or any extension thereof. If actual construction of the reclamation works has not been commenced within 3 years after the segregation of the land or within such further period not exceeding 3 years as may be allowed for that purpose by the State Director, the State Director may, in his discretion, restore the lands to the public domain.

(b) All applications for extensions of the period of segregation must be submitted to the State Director. Such applications will be entertained only upon the showing of circumstances which prevent compliance by the State with the requirements within the time allowed, which, in the judgment of the State Director, could not have been reasonably anticipated or guarded against, such as the distruction of irrigation works by storms, floods, or other unavoidable casualties, unforeseen structural or physical difficulties encountered in the operations, or errors in surveying and locating needed ditches, canals, or pipelines.