Neb. Rev. Stat. § 16-665: Neb. Rev. Stat. § 16-665

The mayor and city council of a city of the first class may provide for the laying of permanent sidewalks and of temporary plank sidewalks upon the natural surface of the ground without regard to the grade, on streets not permanently improved, and provide for the assessment of the cost therein on the property in front of which such sidewalks shall be laid.