All persons who shall build into or over public tidewaters, by authority of the department or by authority of the general assembly, any wharf, pier, bridge, or other structure, or drive any piles into the land under public tidewater, or fill any flats, shall, before beginning the work, give written notice to the department of environmental management of the work they intend to do, and submit plans of any proposed wharf or other structure and of the flats to be filled, and of the mode in which the work is to be performed; and no work shall be commenced until the plan and mode of performing the work shall be approved in writing by the director of the department of environmental management; and the director may alter the plans at his or her discretion and may prescribe the direction, limits, and mode of building the wharves or other structures; provided, that nothing herein contained shall be construed to impair the rights of any riparian proprietors to erect wharves authorized to be erected under any of the laws establishing harbor lines within the state or otherwise by the general assembly.