It is the intention of the Legislature that nothing in Chapters 1 and 2 of this part shall be deemed to change the policy of the State respecting that certain contract entered into between the Federal Government and the State of California made pursuant to an act of Congress of the United States, approved May 15, 1928 (Public, Numbered 391, Seventy-seventh Congress, First Session, 45 Statutes at Large 534, Chapter 569), and an act of the Legislature, approved May 4, 1925 (Chapter 176, Statutes of 1925, Section 8525 of this code), nor shall anything in Chapters 1 and 2 of this part be deemed or construed to modify, limit or take away from the powers and duties vested in the department by any law or in the Reclamation Board pursuant to the provisions of Part 4, Division 5, of this code.