Oregon Revised Statutes Water Resources: Irrigation, Drainage, Flood Control, Reclamation § 554.160

(1) When any bonds or obligations of the corporation are payable from revenue of assessments pledged for the payment thereof, the board of directors shall, at the time of creating such indebtedness or issuing such bonds or obligations or at any time thereafter when assessments therefor are made, designate such fund by appropriate name and shall at the time of making each assessment thereafter determine the amount and portion of the assessment in dollars which is required to be then made for revenue of such fund. In determining and levying every assessment provided in ORS 554.005 to 554.340 the board of directors shall provide separately for the amount to be so raised for each of the several funds so designated and named including the general operation and maintenance fund.

(2) The revenues apportioned to the funds pledged to the payment of bonds and obligations shall be separately held and kept and accounted for. The corporation shall disburse the funds only for the purposes for which levied until the indebtedness and obligation for which the assessment was made is fully paid with interest, whereupon the remainder shall be transferred to the general fund of the corporation for the payment of expenses of the corporation and its operation and maintenance. At the time of making assessments the board of directors shall first determine the estimated amount necessary for the expenses of operation and maintenance and then the several amounts for the respective funds, and determine that the whole amount thereof is within the limitations, restrictions and provisions of the landowners' notice provided for in ORS 554.170 to 554.190.