Neb. Rev. Stat. § 16-250: Neb. Rev. Stat. § 16-250

A city of the first class may construct or repair sidewalks, sewers, and drains on any highway in the city, construct or repair iron railings or gratings for areaways, cellars, or entrances to basements of buildings, and levy a special assessment on lots or parcels of land fronting on such sidewalk, waterway, highway, or alley to pay the expense of such improvements, to be assessed as a special assessment. Unless a majority of the owners of the property subject to assessment for such improvements petition the city council to make the improvements, such improvements shall not be made until three-fourths of all the members of the city council, by vote, assent to the making of the improvements, which vote, by yeas and nays, shall be entered of record.