The bonded indebtedness or security interest of any creditor of any common sewer district originally organized and existing under sections 204.250 to 204.270 and any sewer district originally organized and existing under chapter 249 that convert to a reorganized common sewer district shall not be impaired or affected by such conversion, and all covenants and obligations of such indebtedness shall remain in full force and effect, payable under the terms and conditions that existed without conversion.