Neb. Rev. Stat. § 15-713: Neb. Rev. Stat. § 15-713

To pay the cost of curbing and guttering public ways in a city of the primary class, the city council may issue bonds called curbing gutter bonds, district No. ......, payable in not more than twenty years or at the option of the city at any interest-paying date, and assess the cost, not exceeding the special benefits, on abutting property as special assessments. Such assessments shall become due, delinquent, draw interest, and be subject to like penalty and collected as special assessments and shall constitute a sinking fund for the payment of such bonds. No paving bonds and no curbing gutter bonds shall be sold or delivered until necessary to make payments for work done on such improvements.