Minn. Stat. § 465.17: MAY ISSUE BONDS.

In order to carry out the purpose of sections 465.15 to 465.17 each such city is hereby authorized to issue bonds or certificates of indebtedness to secure funds for the amount necessary to acquire the right and the city council or other chief governing body shall levy annually a tax on all the taxable property of the city sufficient to meet the interest and the principal about to mature on the bond.