ORS § 223.886
In carrying out the powers conferred by ORS 223.882, the city may borrow money from any person, corporation or agency of the United States Government for the purchase of any real property described in ORS 223.882, or for paying the cost of improvements on any real property, which improvements may include the construction of docks, wharves or other structures and appurtenant appliances or fixtures or machinery necessarily required to operate a wharf or dock. In borrowing money for any of these purposes the cities may secure money so borrowed by executing and giving a mortgage or similar indenture on any such real property and its revenues. If repayment of money borrowed for acquisition or improvement of any such real property is not to be secured solely by the real property and the income derived therefrom, then, before a debt for the purpose of this section or ORS 223.882 can be contracted or incurred, the consent of the electors of the city must first be obtained.
ORS 223.886