Oregon Revised Statutes Public Financial Administration § 294.925

(a) An occurrence or condition which had not been ascertained at the time of the preparation of a budget for the current year which requires a change in financial planning.

(b) A pressing necessity which was not foreseen at the time of the preparation of the budget for the current year which requires prompt action.

(c) Funds were made available by another unit of federal, state or local government and the availability of such funds could not have been ascertained at the time of the preparation of the budget for the current year.

(d) A request for services or facilities, the cost of which shall be supplied by a private individual, corporation or company or by another governmental unit and the amount of the request could not have been accurately ascertained at the time of the preparation of the budget for the current year.

(e) The involuntary destruction, involuntary conversion, or sale of property has necessitated the immediate purchase, construction or acquisition of different facilities in order to carry on the governmental operation.