Section 3. The department shall have all the rights, powers and duties transferred to the directors of the port of Boston under section four of chapter seven hundred and forty-eight of the acts of nineteen hundred and eleven in respect to lands, rights in lands, flats, shores, waters and rights belonging to the commonwealth in tide waters and land under water in Boston harbor, or which adjoin the same or are connected therewith, and shall have the same powers and duties relative thereto as it has with respect to the commonwealth flats under section two. It may, in accordance with such plans as it adopts, excavate and dredge in Boston harbor wherever public convenience and necessity require. It shall at all times have access to any maps, charts, plans and documents in the custody of any public board, commission or officer relating to waters and lands in charge of the department, shall have immediate charge of lands owned or acquired by the commonwealth upon or adjacent to the Boston harbor front, and shall have charge of the construction of piers and other public works in said harbor, shall administer all terminal facilities under control of the department and shall secure and keep full information as to the present and probable future requirements of steamships and shipping and the best means which can be provided at the port of Boston for the accommodation of steamships, railroads, warehouses and industrial establishments.