ORS § 545.095
The cost of constructing, purchasing, operating, maintaining and improving the works described in an engineering plan for a subdistrict shall be charged to the owners of the lands, or assessed against the lands, benefited by the works in proportion to the benefits to be received by each tract of land. The charges or assessments shall be in addition to the regular charges or assessments of the district under ORS 545.471. Only the lands or owners within a subdistrict shall be liable for, charged with or in any manner assessed for the payment of judgments, claims, damages, costs, expenses, debts or other liabilities of or against a district that arise out of or are incurred in the constructing, purchasing, operating, maintaining or improving of the works of the subdistrict.
ORS 545.095
See note under 545.093.