Except as otherwise specifically provided by the principal Act:
(1) A district may consist of contiguous or noncontiguous territory located in one or more adjoining counties. If any part of the territory subject to a petition for formation or annexation is within a city, the petition shall be accompanied by a certified copy of a resolution of the governing body of the city approving the petition.
(2) A district may not include territory included within another district formed under the same principal Act when the other district is authorized to perform and is performing the services the affected district is authorized to perform, unless:
(a) Withdrawal of such territory is proposed and the territory is withdrawn by withdrawal proceedings conducted in the other district simultaneously with the formation or annexation proceedings, and the proposed boundary changes are approved for both districts; or
(b) The principal Act provides for automatic withdrawal of the affected territory in such a case.
(3) The boundary lines of a district formed under ORS 198.705 to 198.955 shall include only such territory as may in reason be served by the facilities or services of the district.
(4) For purposes of ad valorem taxation, a boundary change must be filed in final approved form with the county assessor and the Department of Revenue as provided in ORS 308.225.