Neb. Rev. Stat. §§ 17-510
If a petition is signed by the owners of the record title representing more than sixty percent of the front footage of property directly abutting upon the streets, alleys, public ways, or public grounds proposed to be improved in an improvement district created pursuant to section 17-509 and presented and filed with the city clerk or village clerk, the governing body of the city or village shall by ordinance create an improvement district, cause such work to be done or such improvement to be made, contract for such improvement, and levy special assessments on the lots and parcels of land abutting on or adjacent to such streets or alleys specially benefited by such improvement in such district in proportion to such benefits, except as provided in sections 19-2428 to 19-2431, to pay the cost of such improvement. The governing body may deny the formation of the proposed improvement district when the area has not previously been improved with a water system, sewer system, and grading of streets. If the governing body denies a requested improvement district formation, it shall state the grounds for such denial in a written letter to interested parties.
Neb. Rev. Stat. §§ 17-510