Mo. Rev. Stat. § 77.670: Reserve funds, certain third class cities may establish (including North Kansas City).

The governing body of any third class city with a population of more than four thousand but less than four thousand five hundred inhabitants that is located in a county of the first classification with a population of more than one hundred fifty thousand but less than one hundred seventy thousand inhabitants may establish, by ordinance, reserve funds. In the ordinance establishing the reserve funds, the city may either earmark the funds for a specific project, or for operations in general. The repeal or amendment of any such ordinance shall be approved by the qualified voters of the city.