Neb. Rev. Stat. §§ 13-2819
A municipal county may by ordinance cause any unconsolidated sanitary and improvement district located (1) within the extraterritorial zoning jurisdiction of an unconsolidated municipality with the consent of the governing body of the unconsolidated municipality, or (2) within any portion of the municipal county, to be consolidated, in whole or part, into the municipal county, and thereafter the municipal county shall succeed to the property and property rights of every kind, contracts, obligations, and choses in action of every kind, held by or belonging to the sanitary and improvement district, and the municipal county shall be liable for and recognize, assume, and carry out the valid contracts and obligations of the district. Any such consolidation, in whole or in part, shall be accomplished by the municipal county and the sanitary and improvement district in accordance with sections 31-763 to 31-766, and other applicable law, as if the municipal county were a city and the consolidation were an annexation or partial annexation.
Neb. Rev. Stat. §§ 13-2819