Neb. Rev. Stat. §§ 17-976
For the purpose of paying the cost of improvements in any water service district and the funding of any warrants issued, the governing body may by ordinance cause to be issued bonds of the city or village to be called Water Service District Bonds of District No. ..., payable in not to exceed ten years from date and to bear interest payable annually or semiannually. Such bonds shall be general obligations of the city or village, and the governing body shall levy and collect annually a tax upon all of the taxable property in such city or village sufficient in rate and amount to pay in full, when taken together with the assessments provided for in section 17-971, the principal and interest of such bonds as the same become due. The amount of such tax shall not be included in the maximum amount of tax which any such city of the second class or village is authorized to levy annually.
Neb. Rev. Stat. §§ 17-976