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Aquatic Resources Mitigation Framework

Improving Oregon’s Approach to Compensatory Mitigation


The statewide mitigation program has been updated to cover all aquatic resources using a watershed-based approach and function-based mitigation requirements.

This new approach to compensating for wetland and stream losses was collaboratively implemented by the Oregon Department of State Lands (DSL), US Army Corps of Engineers-Portland District (Corps) and US Environmental Protection Agency-Region 10 (EPA) in April 2019.

What is compensatory mitigation? 

Under Oregon's Removal-Fill Law and Section 404 of the federal Clean Water Act (CWA), impacts to aquatic resources require a permit from DSL and the Corps. Mitigation requires a series of steps, called a mitigation sequence, to eliminate or reduce the negative effects of a proposed project. The sequence includes avoidance, minimization and compensation for unavoidable impacts. 

There are two basic compensatory mitigation options: purchasing credits from a mitigation bank or in-lieu fee site, or permittee-responsible mitigation, usually conducted on the project site. Both the Corps website and DSL website have detailed information on mitigation.


Why was the mitigation policy changed? 

In 2008, the federal government adopted a new rule – the Final Compensatory Mitigation Rule – which promotes a watershed- and function-based approach to compensatory mitigation. Studies show that the current practice of requiring acreage-based mitigation is leading to an overall loss of functions and values of aquatic resources across the nation.  The new mitigation framework aims to bring Oregon's mitigation program into alignment with the federal standard and to provide more successful, sustainable benefits for the environment. 

What tools will support the new mitigation program? 

Science-based tools inform mitigation planning and decision-making. These tools will help improve consistency and transparency in the mitigation process. Several function assessment tools and online data viewers are available to the public:

Oregon Rapid Wetland Assessment Protocol (ORWAP) – version 3.2 was released in April 2020 and can be used to assess functions and values of wetlands across the state.

Stream Function Assessment Method (SFAM) – version 1.1 can be used to assess the functions and values of wadable, non-tidal streams across the state. SFAM consists of the Workbook used to calculate function and value scores for given site, the User Manual that provides step-by-step instructions and guidance on completing an SFAM Assessment, and a Scientific Rationale document that describes the development of SFAM and provides supporting information from the scientific literature. Training videos for the office portion of the assessment are available.

Aquatic Mitigation Topic Page & Map Viewers – The topic page hosts the ORWAP Map Viewer and SFAM Map Viewer, used to complete the office portion of an ORWAP or SFAM assessment, respectively; and a Mitigation Planning Map Viewer, used for strategically planning mitigation projects.

Outreach and Training

Recorded webinars and training videos are available to provide information on the program changes and new assessment method.

The March 5, 2019 webinar provides an overview of how the new Aquatic Resource Mitigation Framework was developed and timeline for implementation. Sections of the webinar review the upcoming changes – including what functional assessments can be used in Oregon, how many functional assessments will be needed in permit applications, determining mitigation site eligibility and obligation for wetlands and non-wetlands, and effects on the mitigation banking program. The recording includes the question and answer session that followed DSL's presentation.





Body of water surrounded by treees and green grass


Dana Hicks
Planning and Policy Manager
Oregon Department of State Lands
Phone: 503-986-5229
Tracie Nadeau
Regional Mitigation Lead
U.S. Environmental Protection Agency
Phone: 503-326-3685