None of the obligations of the merged districts or of a local improvement district therein shall be affected by the merger and dissolution, and all land liable to be assessed to pay any of such indebtedness shall remain liable to the same extent as if the merger had not been made, and any assessments theretofore levied against the land shall remain unimpaired and shall be collected in the same manner as if no merger had been made. The commissioners of the merged district shall have all the powers possessed at the time of the merger by the commissioners of the two districts, to levy, assess and cause to be collected all assessments against any land in both districts which may be necessary to provide for the payment of the indebtedness thereof, and until the assessments are collected and all indebtedness of the districts paid, separate funds shall be maintained for each district as were maintained before the merger: PROVIDED, That the board of the merged district may, with the consent of the creditors of the districts merged, cancel any or all assessments theretofore levied, in accordance with the terms and conditions of the merger, to the end that the lands in the respective districts shall bear their fair and proportionate share of such indebtedness.