Whenever the department has entered into an agreement under RCW 47.08.040 with the federal government or any agency thereof requiring the execution of any deed, flowage easement, or instrument of any nature, to the federal government or agency, and the instrument is approved as to form by the attorney general of the state of Washington, the governor of the state of Washington is authorized and directed without further authority and in the name of the state of Washington to execute and deliver to the proper agency of the federal government any such instrument or instruments which shall be, when attested by the secretary of state, binding upon the state of Washington.