ORS § 547.150
All claims against the district shall be paid by warrants drawn on the district treasurer and signed by the president and secretary of the board. When any warrant is not paid when presented to the treasurer because of lack of funds in the treasury, such fact shall be indorsed on the back of the warrant, and such warrant shall draw interest thereafter at the rate of six percent per annum until there is money on hand to pay the amount of the warrant and the interest then accumulated. No interest shall be allowed on warrants after sufficient funds are in the treasury to pay the indorsed warrants and interest. The secretary shall give notice by publication whenever sufficient funds are available to pay outstanding warrants. The board shall charge or levy each year a sufficient amount of money to pay the outstanding warrants of the district to the extent permitted within the constitutional limitation.
ORS 547.150