(1) Any state or state-assisted activity or undertaking proposed within the Niobrara scenic river corridor shall be consistent with the purpose of the scenic river designation, including the scenic river's free-flowing condition and scenic, geological, biological, agricultural, historic, and prehistoric resources.

(2) The head of any state or local agency having direct or indirect jurisdiction over a proposed state or state-assisted undertaking within the Niobrara scenic river corridor and the head of any agency having authority to license or permit any undertaking in such area shall prepare a detailed proposal and submit it to the Niobrara Council for its review.

(3) The council shall review the proposal and consult with the agency. The council has ninety days after the date that the proposal is received to make a determination of whether or not the proposed action is consistent with the purposes of this section. If the council determines that the proposal is not consistent with the purposes of this section, the council shall so notify the agency and the agency shall not proceed with the action until after a justification for the action has been submitted to the Governor and approved by the Governor in writing. The justification shall include the following elements: The anticipated current, future, and cumulative effects on the scenic and natural resources of the designated scenic river corridor; the social and economic necessity for the proposed action; all possible alternatives to the proposed action including a no-action alternative; the comparative benefits of proposed alternative actions; and the mitigation measures outlined in the proposed action.