Unless it shall appear affirmatively that the adoption of such proposed amendment will be contrary to the best interests of such district, or that it will jeopardize and impair the rights of the creditors of such districts, or of other persons, the Nebraska Power Review Board shall issue in duplicate a certificate of approval of such proposed amendment, and cause one copy to be filed in the office of the Secretary of State of the State of Nebraska and one copy to be filed in the office of the county clerk of the county in which is located the principal place of business of the district.