If, as a result of such further investigation, the department shall be of the opinion that such management and control of the outlet and the connected instrumentalities is lawful, and that changes in such management and control in the public interest would deprive the owner of the outlet or others of rights to which they are lawfully entitled and that such changes, notwithstanding such deprivation, would be for the public interest, it may estimate all damages which would be occasioned by such changes and all other connected costs and report its findings to the governor and council.