Oregon Revised Statutes Protection from Fire § 478.470

All warrants for the payment of any indebtedness of a district which are unpaid for want of funds shall bear interest at a rate to be fixed by the district board but not to exceed six percent per annum from the date of the registering of the unpaid warrants with the county treasurer. The amount of warrants outstanding shall not exceed the revenue provided for the year in which the indebtedness was incurred.