(1) Upon the allowance of a petition for inclusion of lands and when an appeal has not been filed within 30 days after entry of the order, a certified copy of the order of the board of directors including the lands in the district shall be filed for record in the office of the county clerk of each county in which lands of the district are situated. The district as changed and all lands in the district shall be liable for all existing obligations and indebtedness of the district.
(2) An appeal may be taken from the order of the board as provided in ORS 548.105 to 548.115. If an appeal is not taken, the order of inclusion shall be deemed lawful and conclusive against all persons. The order shall not thereafter be questioned in any manner in any proceedings.