Or. Admin. R. 141-085-0680 - Compensatory Mitigation (CM); Applicability and Principal Objectives

(1) Applicability. OAR 141-085-0680 through 141-085-0755 applies to removal-fill that occurs within waters of this state and applies to all forms of compensatory mitigation (i.e., mitigation bank, in-lieu fee mitigation, advance mitigation, permittee responsible mitigation, and payment in-lieu mitigation). The Department may establish CM requirements other than those explicitly set forth in OAR 141-085-0680 through 141-085-0755 within areas covered by an approved Wetland Conservation Plan or Advance Aquatic Resource Plan.

(2) Principal Objectives for CM. For projects where impacts to waters of this state cannot be avoided, CM will be required to compensate for the reasonably expected adverse impacts in fulfillment of the following principal objectives.

(a) The principal objectives of CM are to:

(A) Replace functions and values lost at the removal-fill site;

(B) Provide local replacement for locally important functions and values, where appropriate;

(C) Enhance, restore, create or preserve waters of this state that are self-sustaining and minimize long-term maintenance needs;

(D) Ensure the siting of CM in ecologically suitable locations considering: local watershed needs and priorities; appropriate landscape position for the waters types, functions and values sought; connectivity to other habitats and protected resources; and the absence of contaminants or conflicting adjacent land uses or development trends that would compromise functions and values; and

(E) Minimize temporal loss of waters of this state and their functions and values.

(b) Applicants must demonstrate how the selected method of CM (i.e., mitigation bank, in-lieu fee mitigation, advance mitigation, permittee-responsible mitigation and payment in-lieu mitigation) addresses the principal objectives.

(3) General Requirements.

(a) Replacement for locally important functions and values may be required.

(b) Projects that involve 0.20 acres or less of permanent wetland impact may use mitigation banks, in-lieu fee, or payment in-lieu mitigation without addressing the principal objectives set forth in Section (2) of this rule, except when impacts are to Aquatic Resources of Special Concern.

(c) Payment in-lieu mitigation may not be used if appropriate mitigation bank or in-lieu fee credits are available on the day that the public review period closes.

(d) CM earthwork must be completed within the same construction season as the authorized removal-fill project. The Department may approve non-concurrent CM if the applicant clearly demonstrates, in writing, the reason for the delay or that there is benefit to the aquatic resources in doing so.

(e) CM involving the conversion of a water of this state to a different type, HGM class or Cowardin class may not be approved when the existing aquatic resource is in good condition, is an Aquatic Resource of Special Concern, provides locally important functions or values, or supports listed species or a rare plant community or communities.

(f) CM projects must not degrade areas with existing high natural resource values (e.g., forested uplands).

(g) CM hydrology must be self-sustaining and must not rely on features or facilities that require frequent and regular long-term maintenance and management. For example, permanent water control structures may be acceptable, whereas pumping from a groundwater well to provide adequate hydrologic support is not acceptable.

(h) Multiple Purpose CM. CM sites may fulfill multiple purposes including storm water retention or detention, provided:

(A) All other CM requirements are met;

(B) No alteration or management is required to maintain the functionality of the stormwater facility that would degrade the CM functions and values;

(C) The stormwater entering the CM site has been pretreated to the level necessary to assure that state water quality standards and criteria are met in the mitigation area;

(D) Construction of storm water facilities in existing wetlands meets the criteria for enhancement in OAR 141-085-0694 (1);

(E) Construction of the CM site will not adversely affect adjacent waters of this state;

(F) Construction of the CM site will not significantly change pre-development hydrologic conditions, significantly increase peak flows or significantly change the velocity to receiving streams; and

(G) Stormwater discharges to existing or CM wetlands will not result in hydrologic conditions that impair vegetation or substrate characteristics necessary to support wetland functions.

(i) CM for Linear Projects. The Department will review and approve CM for linear projects (e.g., roads or utility lines) that cross multiple waters of this state or that may occur in multiple watersheds on a case-by-case basis and may establish other CM requirements than those explicitly set forth in these rules.

Notes

Or. Admin. R. 141-085-0680

DSL 1-2009, f. 2-13-09, cert. ef. 3-1-09; DSL 8-2009, f. 12-15-09, cert. ef. 1-1-10; DSL 1-2011, f. & cert. ef. 3-1-11; DSL 3-2012, f. 9-28-12, cert. ef. 9-29-12; DSL 3-2014, f. 8-14-14, cert. ef. 9-1-14; DSL 2-2019, amend filed 03/28/2019, effective 4/1/2019; DSL 4-2019, minor correction filed 04/10/2019, effective 4/10/2019

Statutory/Other Authority: ORS 196.825 & ORS 196.600-196.692

Statutes/Other Implemented: ORS 196.600-196.692 & 196.800-196.990