Not later than September 30, 1981, the Secretary of Transportation shall transmit to Congress a final report of the study required by this section, together with his findings and recommendations (including necessary legislation) and the findings and recommendations of the Secretary of Commerce, the Secretary of the Treasury, the Secretary of Agriculture, the Secretary of Energy, the Attorney General of the United States, the Secretary of the Army, the Chairman of the Water Resources Council, and the Director of the Office of Management and Budget.