Neb. Rev. Stat. §§ 14-2157
The existence of a metropolitan utilities district may be terminated by the people of the district in the following manner: Upon the filing of a petition with the board of directors signed by fifteen percent of the registered voters of the district at least thirty days prior to the date of any general state election requesting that the question of the continuance or termination of the existence of such district be submitted to a vote of the registered voters of the district, it shall be the duty of such board to submit the question at such general state election, and if a majority of the votes cast thereon shall be in favor of the continuance of such district, then it shall continue, otherwise its existence shall cease at the close of the thirty-first day of the following month.
Neb. Rev. Stat. §§ 14-2157