Appointment of commissioners when plan amended; subsequent proceedings; court costs. (1) If the judgment of the court provides that the plan for reclamation may be amended, changed or corrected or the boundary lines of the district extended, the court shall appoint three commissioners, possessing the same qualifications as the commissioners appointed under ORS 547.215, to appraise property to be taken, assess benefits and damages, and estimate the cost of improvements the same as is required of commissioners acting under ORS 547.225. The commissioners shall make their report in writing and file it with the county clerk, after which the case shall be proceeded with in the same manner as is provided for the organization of drainage districts

ORS 547.260 — under Chapter 547.