ORS § 227.300
The council or other governing body of any incorporated city, under an exercise of the power of eminent domain, may establish or alter building setback lines on private property adjacent to any alley, street, avenue, boulevard, highway, or other public way in such city in cases where the establishment of such setback lines is for street widening purposes, and in cases where the establishment of such setback lines affects buildings or structures existing at the time. The council or other governing body of the city shall pass and put into effect such ordinances as may be needed for the purpose of providing for a notice to and hearing of persons whose property is affected by such establishment. In case of the exercise of the power of eminent domain, provision shall be made for ascertaining and paying just compensation for any damages caused as the result of establishing such setback lines.
ORS 227.300