Minn. Stat. § 456.31: MAY SELL ALL BONDS AT ONCE IN SPITE OF ORDINANCE.

If the people of a city of the first class have approved an ordinance to let the city issue bonds to extend, enlarge, and improve its city-owned and operated waterworks, and if the ordinance allows only a specified portion of the bonds to be issued in any one year, the city may issue all, or some, of the bonds remaining unissued at any time, notwithstanding the ordinance.