Neb. Rev. Stat. §§ 15-228
The city council shall have the power to create water districts for the purpose of supplying water for domestic, industrial, or fire purposes, or for the purpose of enlarging any water mains, now existing or hereafter constructed. All such districts, to be known as water districts, shall be created by ordinance and shall designate the property to be benefited. Upon creation of any water district, the city council shall have the power to construct or cause to be constructed, either by contract with the lowest responsible bidder or directly by the city, such water main or mains, or extensions or enlargements, including all necessary appliances for fire protection, within such districts as the city council shall determine, and assess the costs thereof against the property in such district, not exceeding the special benefits accruing on account thereof. The city council shall have the power and authority to fix the period of time, not to exceed twenty years, in which the special assessments against any property for the payment of the cost of such improvements may be made. The city council shall have the power and authority to issue bonds in accordance with the provisions of a home rule charter of the city or of state law.
Neb. Rev. Stat. §§ 15-228