Neb. Rev. Stat. § 70-1103

Nothing contained in sections 70-650.01 and 70-1101 to 70-1106 shall in any manner be construed so as to impair the obligations of the public power district to the holders of its outstanding bonds. The municipalities shall properly operate and maintain such system according to the obligations of the district to its bondholders. The municipalities shall maintain and keep separate books and records of the operations of the property of the district in the same manner as such books and records were kept by the district and shall account and pay to the district the same revenue from the property it acquires which the district would have received from the property it transfers to the city if the district had remained the operator of such property.