Or. Rev. Stat. § 450.987
Upon formation of a water authority or sanitary authority, a city may annex territory situated within the boundaries of the water authority or sanitary authority, but shall not remove any water mains, sewers and drains, service installations, reservoirs, structures, facilities and other improvements or any service provision capability from the water or sanitary authority unless the county governing body or boundary commission determines that:
[Formerly 450.670; 1993 c.577 §34]