(2) Except in case of default of the district, the board of directors may enter into an agreement with the owner of the tract of land who makes the payment, relieving the tract of all existing assessments and liens, except warranted indebtedness, state interest, and operation and maintenance. The transaction shall be recorded in the minutes of the board of directors of the district.
(3) Any additional cash payment collected by the board under subsection (1) of this section shall be deposited with the treasurer of the district and placed in a separate fund, which shall be used only for the retirement of bonds. [Formerly 545.216]