Neb. Rev. Stat. § 46-172

In case of the inclusion of any land within any district by proceedings under section 46-161 the board of directors must, at least thirty days prior to the next succeeding general election, make an order redividing such district into three divisions, as nearly equal in size as may be practicable, which shall be numbered first, second and third, and one director shall thereafter be elected by each division. For the purpose of elections the board of directors shall establish one or more election precincts in the districts and define the boundary or boundaries thereof, which may thereafter be changed from time to time as the board may deem necessary.