The Department of Playground and Recreation of the City shall have jurisdiction, possession and control of all tidelands and submerged lands, whether filled or unfilled, situated below the line of mean high tide within the limits of the City extending from the United States Government breakwater at San Pedro to the most northwesterly boundary of said City, and shall have sole and complete jurisdiction, control and possession of all public beach lands within the above mentioned confines except as otherwise in this article provided. All rights and duties of the City as a littoral, upland or riparian owner of the above described lands shall be exercised by the Department of Playground and Recreation.