In any valuation for rate-making purposes, or in any proceeding for the acquisition of rights to the use of water and the property used in connection therewith, under any license or statute of the United States or under the laws of Oregon, no value shall be recognized or allowed for such rights in excess of the actual cost to the owner of perfecting them in accordance with the provisions of the Water Rights Act. [Formerly 537.280; and then 537.335]