In furtherance of any comprehensive plan formulated on and after Dec. 21, 1928 for the control, improvement, and utilization of the resources of the Colorado River system and to the end that the project authorized by this subchapter may constitute and be administered as a unit in such control, improvement, and utilization, any commission or commissioner duly authorized under the laws of any ratifying State in that behalf shall have the right to act in an advisory capacity to and in cooperation with the Secretary of the Interior in the exercise of any authority under the provisions of sections 617c, 617d, and 617m of this title and shall have at all times access to records of all Federal agencies empowered to act under said sections, and shall be entitled to have copies of said records on request.