Neb. Rev. Stat. § 16-684.01: Neb. Rev. Stat. § 16-684.01

After the establishment of a system of waterworks in any city of the first class, the mayor and city council may expend any accumulated reserve funds in its water department for the purpose of laying and relaying water mains and the installation of water equipment for fire protection. The city shall have the power and authority to employ the necessary labor therefor without the necessity of advertising for bids or of letting a contract or contracts therefor.