Neb. Rev. Stat. § 14-1221
The proceeds of any revenue bonds issued by a city of the metropolitan class pursuant to section 14-1217 shall be deposited in the first instance with the city treasurer and thereafter with such depositories as the bridge commission shall direct and the city council shall approve, shall be secured in such manner and to such extent as the city council and the bridge commission shall require, shall be used solely for the payment of the cost of such bridges and costs incident to such bridges, and shall be drawn upon over the signatures of the chairperson or vice-chairperson of the bridge commission and the secretary and treasurer of the bridge commission, and under such further restrictions, if any, as the city council may provide. If the face amount of such bonds, less any discount on the sale of such bonds, shall exceed such cost, the surplus shall be paid into such funds provided for the payment of the principal and interest of such bonds.
Neb. Rev. Stat. § 14-1221