No inferior right to the use of the waters of this state shall be acquired by a superior right without just compensation therefor to the inferior user. The just compensation paid to those using water for power purposes shall not be greater than the cost of replacing the power which would be generated in the plant or plants of the power user by the water so acquired. The just compensation to be paid to a holder of an instream-basin-management appropriation that has been changed from a manufacturing of hydropower appropriation pursuant to section 46-290 shall be the cost per acre-foot of water subordinated for the hydropower appropriation at the time of approval of the change. The amount of compensation may be adjusted annually, except that any increase shall not exceed the annual change in the Consumer Price Index from the time of approval of the change. If publication of such index is discontinued, a comparable index selected by the Director of Natural Resources shall be used.