S.C. Code § 54-5-10
All cities of this State having a population of fifty thousand inhabitants or more, located upon a navigable stream, whether tidal or nontidal, may purchase or otherwise acquire, within or without or partly within and partly without the corporate limits of such cities, lands, water or riparian rights, wharves, docks, warehouses, buildings, rights of way and any other property for the purpose and with the right of establishing, constructing, developing, improving, maintaining and operating the port and terminal utilities of such cities in aid of the commerce and for the public use and benefit of such cities and their citizens, with the right to make any and all contracts, rules, rates and regulations necessary or incident to that end.
S.C. Code § 54-5-10