Acquisition of wharves and landings; expropriation

The board of commissioners may acquire by purchase, or by expropriation in accordance with the expropriation laws, any property, wharves, or landings necessary for the benefit of the commerce of the port and harbor of New Orleans. But the board of commissioners may expropriate without compensation any private wharves, landings, buildings or other structures erected by riparian owners within the port limits of the port of New Orleans, whenever such wharves, landings, buildings or other structures have been erected by the riparian owners without first obtaining the consent of the board for the construction or erection of the same, and its approval of the plans and specifications for their construction or erection.