Neb. Rev. Stat. §§ 70-651.03
Beginning in 1960, every public corporation and political subdivision of the state, which is organized primarily to provide electricity or irrigation and electricity, and which sells electricity at retail within incorporated cities or villages, shall on or before April 1, of each year, pay to the county treasurer of the county in which any such incorporated city or village may be located, a sum equivalent to five percent of the gross revenue derived by it during the preceding calendar year from retail sales of electricity within such incorporated city or village, less an amount equivalent to the amount paid by such public corporation in lieu of taxes in the 1957 calendar year with respect to its properties in such city or village.
Neb. Rev. Stat. §§ 70-651.03