Neb. Rev. Stat. §§ 46-178
If there are outstanding bonds of the district or if the district shall have entered into a contract with the United States, as provided in section 46-126 or 46-156, then the board may adopt a resolution to the effect that the board deems it to the best interests of the district that the lands mentioned in the petition, or some portion thereof, should be excluded from the district. The resolution shall describe such lands so that the boundaries thereof can be readily traced. The holders of such outstanding bonds may give their assent in writing to the effect that they severally consent that the board may make an order by which the lands mentioned in the resolution may be excluded from the district and in case a contract has been made with the United States, as aforesaid, the Secretary of the Interior may assent to such change. The assent may be acknowledged by the several holders of such bonds in the same manner and form as are required in case of a conveyance of land, and the acknowledgment shall have the same force and effect as evidence as an acknowledgment of such conveyance, except the assent of the Secretary of the Interior need not be acknowledged. The assent must be filed with the board and must be recorded in the minutes of the board; and such minutes, or a certified copy thereof, shall be admissible in evidence with the same effect as the assent; but if such assent of the bondholders and, in case of contract with the United States such assent of the Secretary of the Interior, is not filed, the board shall deny and dismiss the petition.
Neb. Rev. Stat. §§ 46-178