Neb. Rev. Stat. § 16-221: Neb. Rev. Stat. § 16-221

A city of the first class may establish, alter, and change the channel of watercourses, and wall and cover them over. No city shall be liable in damages on account of the accumulations of surface waters which fall upon its site, or any portion thereof, unless such accumulations be caused by the act of a city officer while employed in his or her official capacity and by authorization of the mayor and city council first entered of record.