OAR 141-085-0692: Mitigation Accounting

(1) The purpose of mitigation accounting is to: (a) Ensure that the total area of the state’s wetland and tidal waters resource base is maintained; (b) Replace functions and values, including those that may be size dependent; (c) Account for temporal loss of habitat types, functions, and values; and (d) Encourage long-term sustainability of CM projects. (2) Ratios will not be used as the sole basis for demonstrating functional replacement. (3) Minimum Requirements. Except as otherwise provided in this section, the following minimum ratios must be used in the development of CM plans: (a) One acre of restored or created wetland or tidal waters for one acre of impacted wetland or tidal waters (1:1); (b) One credit from a bank, in-lieu fee, or advance mitigation project for one acre of impacted wetland or tidal waters (1:1); (c) Three acres of enhanced wetland or tidal waters for one acre of impacted wetland or tidal waters (3:1); and (d) There is no established ratio for CWM using preservation, or for CNWM. Minimum requirements will be determined on a case-by-case basis by the Department. (4) Adjustments to the Minimum Requirements. The amount of CM will increase based on the following factors but will not reduce the amount of mitigation below the minimum requirements: (a) Degree of specific function and value replacement. Adjustments will be based on the specific functions and values outlined in ORWAP, SFAM, or the Vernal Pool Function Assessment Method for the Agate Desert, if applicable. (A) Differences between the specific functions and values that will be lost at the impact site and the functions and values expected to be produced by the CM project will increase the amount of CM required up to fifty percent. (B) A CM site exceeding, or predicted to exceed, at least eighty percent of the specific functions that will be lost at the proposed impact site will reduce the amount of CM required by twenty percent. (b) Functional temporal loss. Characteristics (e.g., vegetation or soils) that are expected to take time to develop at the CM project and result in temporal loss of functions or values will increase the amount of CM required. This adjustment will not exceed one hundred percent of the minimum requirements and will be limited to the characteristic that has the longest maturity time (i.e., characteristics are not additive). (c) Strengthened administrative protection and long-term stewardship. Provisions for the CM site that are above and beyond the minimum requirements of the Department will reduce the amount of CM required up to twenty percent. Strengthened long-term stewardship must include appropriate funding to implement an approved stewardship plan. Minimum administrative requirements are public ownership with a management plan, or a deed restriction. (d) Impacts to CM Sites. The Department may double the minimum requirements for project development affecting existing CM sites. (e) Unauthorized Removal-Fill. The Department may increase the minimum requirements when mitigation is proposed to compensate for an unauthorized removal-fill activity. (f) Non-concurrent CM. The Department may increase the minimum requirements when mitigation will not be implemented in the same construction season as the authorized impact. (5) Exceptions to Adjustments to the Minimum Requirements. (a) Permittee-responsible mitigation proposed for projects that involve 0.20 acres or less of permanent wetland impact are not subject to an adjustment based on differences between the specific functions and values lost at the impact site and the specific functions and values expected to be produced by the CM project; all other adjustments may apply. (b) Projects that involve 0.2 acres or less of permanent wetland impact that use mitigation banks, in-lieu fee mitigation, or payment in-lieu mitigation are not subject to the adjustments in 141-085-0692(4)(a) to 141-085-0692(4)(c). (c) CM fulfilled using legacy credits are not subject to the adjustments in 141-085-0692(4)(a) to 141-085-0692(4)(c). (6) Buffer Areas. Credit will be granted for required buffers at an amount determined by the Department. Such buffers will be subject to appropriate administrative site protection pursuant to OAR 141-085-0695.