Any city of the first class operating a waterworks department under the provisions of chapter 114*, Laws 1907, and amendments thereof, may construct facilities, improvements or extensions within or without said city and may sell or dispose of water within or without said city: Provided, Any such city may prohibit or limit the resale of water such city sells. All water lines or facilities now or hereafter located in or on public rights of way, roads, streets, lands or easements and which carry water of a city-owned water plant shall be exclusively subject to regulation by the governing body of such city.