Each fund created under Chapter 16 shall be strictly devoted to the purpose for which it was created and shall not be diverted therefrom. When the city council by a three-fourths vote of the members thereof shall declare the expenditure of any fund for the purpose for which it was created to be unwise and impracticable or where the purpose thereof has been fully accomplished and the whole fund or an unexpired balance thereof remains, and no indebtedness has been incurred on account of such fund which has not been fully paid, such fund may be transferred to any other fund of the city by the affirmative vote of three-fourths of all the members of the city council.
Neb. Rev. Stat. §§ 16-721