Any person proposing to erect or maintain a public elevator or public warehouse for the purchase, sale, storage, receiving or shipping of grain, or other personal property, to be received from or transported upon any water carrier, shall be furnished by such water carrier at a reasonable rental, a site upon its property or terminal; and any private elevator or warehouse situated upon such grounds may be converted into a public elevator or warehouse at the option of the owner, upon notice in writing to the water carrier and thereby be permitted to remain thereon under the same conditions as provided herein for a public elevator or warehouse; and the office shall, upon application by such owner, if the public interest so requires, by order, direct the water carrier to furnish such site and the office shall make reasonable regulations therefor and in case of disagreement, the office shall determine the rental therefor. Elevators and warehouses erected or maintained under the foregoing provisions of this section shall be subject to such rules and regulations as to charges and the manner of conducting business as the office shall prescribe.