Whenever the board of directors of the district shall have adopted a resolution excluding such lands from further participation in the benefits of the district and from the right to receive district waters, the water or water rights theretofore apportioned to the lands shall be and become a part of the general water supply of the district and apportioned among the remaining nondelinquent lands in the same proportion as such remaining nondelinquent lands have been apportioned benefits, not in excess, however, of an adequate water supply for such remaining land based upon the duty of water recognized by the district; but in case the water right appurtenant to land acquired at a delinquent sale shall be based upon a contract with the United States the district may, with the consent of the United States, make any desired disposition of such water right.