ORS § 266.514
In addition to the authority to issue general obligation bonds, a district, when authorized by a majority of those voting at an election called for that purpose, may sell and dispose of revenue bonds, and pledge as security therefor all or any part of the unobligated net revenue of the district or a recreational facility of the district, to purchase, acquire, construct, reconstruct or improve a facility, or to perform any of those acts in combination, for any authorized purpose. Revenue bonds shall be issued in the same manner and form as are general obligation bonds of the district, but they shall be payable, both as to principal and interest, from revenues only. Revenue bonds shall not be subject to the limitation provided by ORS 266.512 applicable to general obligation bonds and shall not be a lien upon any of the taxable property within the limits of the district. Revenue bonds shall be payable solely from such part of the revenue of the district as remains after payment of obligations having a priority and of all expenses of operation and maintenance of the district, including any taxes levied against it. All revenue bonds shall contain a clause reciting that both the principal and interest are payable solely from operating revenues of the district remaining after paying such obligations and expenses.
ORS 266.514