12. (1) If any obstruction or impediment to the navigation of any port subject to this Act has been lawfully made, or has become lawful by reason of the long continuance of such obstruction or impediment, or otherwise, the conservator shall report the same for the information of the Government, and shall, with the sanction of the Government, cause the same to be removed or altered, making reasonable compensation to the person suffering damage by such removal or alteration. (2) Any dispute arising concerning such compensation shall be determined according to the law relating to like disputes in the case of land required for public purposes.