Oregon Revised Statutes Cities § 226.390

The municipal authorities may issue bonds for the costs and expenses of acquiring the private property for any of the purposes mentioned in ORS 226.320 to 226.380. The bonds shall be at such rate of interest and for such length of time as the municipal authorities determine, shall be advertised and sold in such manner as the municipal authorities determine and shall be a general obligation of the city. The municipal authorities shall, at the time of issuing the bonds, make provisions for the payment of interest and a sinking fund for the retirement thereof.