ORS § 545.057
The holders of title, or evidence of title, representing a majority of the acreage of any body of land adjacent to the boundaries of any irrigation district may file with the board of directors of the district a written petition requesting that the body of land be included in the district. For purposes of this section, the body of land may include or consist of one or more parcels of less than one acre, without regard to whether or not the parcels are city lots or tracts of a platted subdivision or are chiefly available for residence purposes. When the body of land is located within the boundary of a city, the petition shall be approved by the governing body of the city before presentation to the board of directors. The petition shall describe the tracts or body of land owned by the petitioners. Reference to the assessor's map and tax lot number is sufficient for the description of lands required under this section. The petition shall give assent of the petitioners to the inclusion into the district of the lands described in the petition. The petition must be acknowledged in the same manner that conveyances of land are required to be acknowledged.
ORS 545.057