Neb. Rev. Stat. §§ 16-6,102
In addition to any other provision of state law, whenever the mayor and city council of any city of the first class shall deem it necessary and advisable to construct sanitary sewer mains or water mains, the mayor and city council may, by ordinance passed by not less than three-fourths of all members of the city council, create a district or districts to be known as sanitary sewer connection districts or water connection districts and such district or districts may include properties within the corporate limits of the city and within the city's extraterritorial zoning jurisdiction. Such ordinance shall state the size and kind of sewer mains or water mains proposed to be constructed in such district and shall designate the outer boundaries of the district or districts in which it is proposed to construct the sewer mains or water mains.
Neb. Rev. Stat. §§ 16-6,102