; 25 U.S.C. 161 ); (ii) the first section of the Act of June 24, 1938 (52 Stat. 1037, chapter 648; 25 U.S.C. 162a ); and (iii) obligations of Federal corporations and Federal Government-sponsored entities, the charter documents of which provide that the obligations of the entities are lawful investments for federally managed funds, including— (I) obligations of the United States Postal Service described in section 2005 of title 39, United States Code; (II) bonds and other obligations of the Tennessee Valley Authority described in section 15d of the Tennessee Valley Authority Act of 1933 ( 16 U.S.C. 831n–4 ); (III) mortgages, obligations, or other securities of the Federal Home Loan Mortgage Corporation described in section 303 of the Federal Home Loan Mortgage Corporation Act ( 12 U.S.C. 1452 ); and (IV) bonds, notes, or debentures of the Commodity Credit Corporation described in section 4 of the Act of March 8, 1938 (52 Stat. 108, chapter 44; 15 U.S.C. 713a–4 ). (C) Credits to account The interest on, and the proceeds from, the sale or redemption of any obligations held in the Hualapai Water Project Account shall be credited to, and form a part of, the Hualapai Water Project Account. (3) Project efficiencies If the total cost of planning, design, and construction activities of the Hualapai Water Project results in cost savings and is less than the amounts authorized to be appropriated under paragraph (6), the Secretary, at the request of the Hualapai Tribe, may— (A) use those cost savings to carry out capital improvement projects associated with the Hualapai Water Project