Neb. Rev. Stat. §§ 31-401
Whenever it will be conducive to the public health, convenience or welfare, to drain any wet land, to drain any land subject to overflow by water, or any land which will be improved by drainage, to build or construct any dike or levee to prevent overflow by water, to construct, straighten, widen, deepen or alter any ditch, drain, stream or watercourse, to riprap or otherwise protect the bank of any stream or ditch, to construct, enlarge, extend, improve or maintain any system of drainage, to construct, enlarge, extend, improve or maintain any system of control of surface water or running water, or to do any two or more of said things jointly, then a drainage district may be formed and may proceed, as hereinafter provided, for the purpose of inaugurating, constructing, controlling and maintaining said work or works of public improvement.
Neb. Rev. Stat. §§ 31-401