Neb. Rev. Stat. §§ 14-362
A city of the metropolitan class shall require the issuance of a permit to connect with any sewer on any street, alley, or private property within the corporate limits or within the extraterritorial zoning jurisdiction of such city and shall require the sewer assessment on the abutting property to be paid before such permit is issued, except that if such assessment is being paid in installments as provided by law, the city shall require delinquent and current installments to be paid before such permit is issued. In case the cost of the sewer has not been assessed, or such assessment has been declared invalid by any court of competent jurisdiction, the city shall require the payment of the pro rata share of the cost of such sewer before such permit is issued.
Neb. Rev. Stat. §§ 14-362