Background about Compensatory Mitigation Requirements under CWA Section 404

This page provides background information regarding the Clean Water Act Section 404 compensatory mitigation requirements.

In 2008, EPA and the U.S. Army Corps of Engineers jointly promulgated regulations revising and clarifying requirements regarding compensatory mitigation.  

• restoration (re-establishment or rehabilitation),
• establishment (creation),
• enhancement, and/or
• in certain circumstances, preservation of wetlands, streams and other aquatic resources. 

Learn more about what restoration, establishment, enhancement and preservation mean.

• avoidance, and
• minimization has been achieved.

Learn more about avoidance and minimization of adverse impacts.

• mitigation banks, 
• in-lieu fee programs, and 
• permittee-responsible mitigation.

• Compensatory Mitigation Regulations
• Compensatory Mitigation Guidance
• RIBITS (Regulatory In-lieu fee and Bank Information Tracking System)
• Compensatory Mitigation Factsheets
• Compensatory Mitigation Training Resources
• Technical Resources for Stream Mitigation
• Recent Compensatory Mitigation Evaluations and Reports
• National Wetlands Mitigation Action Plan

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Compensatory Mitigation Regulations

• Section 404(b)(1) Guidelines In 1980, EPA finalized regulations that constitute the substantive environmental criteria used in evaluating activities regulated under Section 404 of the Clean Water Act

• Compensatory Mitigation for Losses of Aquatic Resources; Final Rule. In 2008, EPA and the U.S. Army Corps of Engineers, through a joint rulemaking, expanded the 404(b)(1) Guidelines to include more comprehensive standards for compensatory mitigation.

  • Background on 2008 Compensatory Mitigation Rulemaking

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Compensatory Mitigation Guidance

• 1990 Memorandum of Agreement - Contains the policy and procedures to be used in determining the type and level of mitigation necessary to demonstrate compliance with the Section 404(b)(1) Guidelines. (Portions of this MOA that concern the type and location of compensatory mitigation are superseded by the 2008 compensatory mitigation rulemaking.)

• Historic (no longer applicable) Guidance Documents

• 2003 Transportation Equity Act for the 21st Century (TEA-21) Guidance (Federal Highway Administration) (PDF) (8 pp, 1.45MB)

• 2003 Federal Aviation Administration Memorandum of Agreement to Address Aircraft-Wildlife Strikes (PDF) (28 pp, 323K)

• 2003 Model Mitigation Plan Checklist (PDF) (8 pp, 2MB)

• 2003 Memorandum to the Field on Adaptation of National Research Council Compensatory Mitigation Guidelines (PDF) (10 pp, 227K)

• Compensatory Mitigation in Alaska - 2018 Memorandum of Agreement between EPA and the Department of the Army

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RIBITS (Regulatory In-lieu fee and Bank Information Tracking System)

RIBITS was developed by the U.S. Army Corps of Engineers with support from EPA and the U.S. Fish and Wildlife Service to provide better information on mitigation and conservation banking and in-lieu fee programs across the country. RIBITS allows users to access information on the types and numbers of mitigation and conservation bank and in-lieu fee program sites, associated documents, mitigation credit availability, service areas, as well information on national and local policies and procedures that affect mitigation and conservation bank and in-lieu fee program development and operation.

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Compensatory Mitigation Factsheets

• Compensatory Mitigation Factsheet (PDF) (2 pp, 432K)

• Mitigation Banks

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  Compensatory Mitigation Training Resources

• 2022 Mitigation Bank and In-Lieu Fee Program Review Workbooks and Checklists

• National Compensatory Mitigation Training Course 

• Environmental Markets Conference

• In-Lieu Fee Mitigation Training Series 

• National Association of Wetland Managers - Training Webinars 

• Compensatory Mitigation Rule Training Materials

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  Technical Resources for Stream Mitigation

• Stream Mitigation Accounting Metrics: Exploring the Use of Linear-based, Area-based, and Volume Units of Measure to Calculate Impacts and Offsets to Different Stream Archetypes (pdf) (8.02 MB, 11/21/2021, EPA 840-R-21-003 ) (PDF) (110 pages, 8 MB) – This technical report, guided by a technical committee representing regionally diverse expertise in stream assessment, restoration, and mitigation and comprised of members from federal, state, and non-profit organizations and academics, explores the use of various units of measure as applied in stream mitigation accounting protocols. It highlights key questions and an analytical process to inform the development and use of scientifically and mathematically credible units of measure in stream mitigation accounting protocols.   

• 2021 U.S. Army Corps of Engineers, Engineer Research and Development Center (ERDC). ERDC convened a multiagency National Committee on Stream Assessment to create guidelines to inform the development of new function-based stream assessment methods and evaluation of both national-level and regional methods currently in use.  

  • Technical Guide for the Development, Evaluation, and Modification of Stream Assessment Methods for the Corps Regulatory Program 

• 2014 Association of State Wetland Managers (ASWM). From 2012 through 2014 ASWM conducted a series of webinars and interviews with States to document and discuss the various ways States address stream jurisdiction, identification, protection and compensation.

  • 2014 Report on State Definitions, Jurisdiction and Mitigation Requirements in State Programs for Ephemeral, Intermittent and Perennial Streams (ASWM now NAWM). Documents the various ways States address stream jurisdiction, identification, protection and compensation.

• 2012 A Function-Based Framework for Stream Assessment & Restoration Projects, EPA 843-K-12-006 (PDF) (344 pp, 8MB) – This report lays out a framework for approaching stream assessment and restoration projects that focuses on understanding the suite of stream functions at a site in the context of what is happening in the watershed.  It has been developed to:

  1. Help the restoration community understand that stream functions are interrelated and generally build on each other in a specific order, a functional hierarchy, and understand that parameters can be used to assess those functions even if some parameters are functions and others are structural measures.

  2. Place reach scale restoration projects into watershed context and recognize that site selection is as important as the reach scale activities themselves.

  3. Provide informal guidance and ideas on how regional stream assessment procedures might incorporate stream functions into debit/credit determination methods, function-based assessments and performance standards.

• 2012 UPDATED Natural Channel Design Review Checklist, EPA 843-B-12-005 (96 pp, 32MB) – This checklist and supporting document has been updated with supplementary materials and has been reformatted. It provides guidance on important items to consider when reviewing natural channel designs. It is intended to provide the reviewer with a rapid method for determining whether a project design contains an appropriate level of information for review and evaluation.  Final Natural Design Checklist (xls) (39 KB)  

• 2011 Appalachian Stream Mitigation Workshop – The workshop included presentations designed to inform state and federal regulatory and resource agencies, who review, comment on and/or approve compensatory mitigation plans for surface coal mining projects in Appalachia. Additional information on the workshop, the presentation materials, and additional resources are provided.

• 2010 Stream Assessment and Mitigation Protocols A Review of Commonalities and Differences (155 pp, 1MB) - This report provides a review of 32 stream assessment protocols and mitigation guidance documents in use by various federal and state government agencies nationwide. It identifies stream functions or conditions assessed, parameters or attributes measured, assessment results obtained, intensity of effort and training needed, use and source of reference condition information, and other factors potentially instructive to parties seeking to review, initiate, or modify stream assessment programs.

  • APPENDIX A (10 pp, 81K) Hydraulic Regional Curves for Selected Areas of the United States

  • PART II (79 pp, 532K) Reviews of Representative Stream Assessment and Mitigation Protocols

2004 Stream Mitigation Protocol Compendium, EPA 843-S-12-002 (212 pp, 1.2MB) - This document is intended as a reference that can be consulted by regulatory agencies, resource managers, and restoration ecologists in order to select, adapt, or devise stream assessment methods appropriate for impact assessment and mitigation of fluvial resources in the CWA Section 404 Program. Memorandum to the Field (2 pp, 714K) 

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Recent Compensatory Mitigation Evaluations and Reports

• An Ecological Approach for Reviewing CWA Section 404 Compensatory Mitigation Projects in EPA Region 4 (pdf) (2.77 MB, October 2023, EPA-904-D-23001)
  In October 2023, EPA published An Ecological Approach for Reviewing CWA Section 404 Compensatory Mitigation Projects in EPA Region 4 (3MB, EPA-904-D-23001).  The Approach is rooted in the  requirements of the Mitigation Rule and draws on the authors’ decades of experience reviewing compensatory mitigation proposals and the ecological restoration literature. The Approach provides a series of questions to organize the review of the ecologically relevant information in a wetland or stream mitigation proposal under the Clean Water Act Section 404 Program.  The authors welcome feedback on the Approach as they continue to develop tools to support the review of compensatory mitigation proposals (Ainslie.William(at)epa.gov; Somerville.Eric(at)epa.gov; and Monroe.Ashley(at)epa.gov).

• A Review of Compensatory Mitigation in Estuarine and Marine Habitats (pdf) (1.5 MB) EPA developed A Review of Compensatory Mitigation in Estuarine and Marine Habitats (February 2023, EPA-843-R-23001) to inform regulators, mitigation providers and the public about compensatory mitigation in estuarine and marine settings. The Report explores four habitats: shallow water, seagrass, oysters, and tidal flats (mudflats); the review describes each of the habitats’ importance and provides examples of mitigation and restoration projects. A comprehensive list of third-party mitigation providers (as of 2021) with estuarine or marine sites, and a subset of permittee-responsible mitigation projects from five coastal states is included.

• An Integrated Framework for Evaluating Wetland and Stream Compensatory Mitigation (pdf) (6.79 MB, March 2022, EPA-840-B-22008) , An Integrated Framework for Evaluating Wetland and Stream Compensatory Mitigation Summary of Pilot Applications (pdf) (3.73 MB, March 2022, EPA-840-s-22001) , and the Data Management Template (xlsx) (87.33 KB, March 2022) have been developed to help states, tribes, and other interested parties develop a long-term, scientifically rigorous approach to evaluating the overall performance of wetland and stream compensatory mitigation programs. The framework combines site-specific and regional evaluations in a flexible, modular approach that allows customization to the needs and status of existing programs.  Recommendations are also included for compensatory mitigation data management to support data accessibility across agency programs and for the public. In addition, a series of examples and case studies are provided to illustrate the concepts presented as well as a summary of two pilot applications of the approach.  EPA’s Office of Wetlands, Oceans, and Watersheds, in partnership with the Southern California Coastal Water Research Project (SCCWRP) and the Environmental Law Institute (ELI) collaborated on this project.

• Handbook on Coral Reef Impacts: Avoidance, Minimization, and Compensatory Mitigation and Restoration.  In December 2016, the U.S. Coral Reef Task Force released a new handbook on coral reef mitigation.  The handbook describes approaches to mitigate both planned and unplanned impacts to coral reefs.

• Stream Mitigation: Science, Policy, and Practice.  In December 2016, the Environmental Law Institute, Stream Mechanics, and The Nature Conservancy released a new stream mitigation handbook.  The handbook examines how stream mitigation has evolved in policy and practice in the more than eight years since issuance of the 2008 Compensatory Mitigation Rule; identifying trends, areas for improvement, and best practices.  The handbook also examines how stream restoration science continues to evolve and what progress can still be made.

• Compensatory Mitigation Site Protection Instrument Handbook for the Corps Regulatory Program.  In July 2016, the U.S. Army Corps of Engineers - Institute for Water Resources (IWR) released a new compensatory mitigation site protection handbook.  The handbook discusses the key considerations associated with the different real estate instruments used to provide durable protection for compensatory mitigation sites.

• Long-Term Stewardship Calculator & Accompanying Handbook.  In May 2016, The Nature Conservancy released a calculator and handbook to help estimate the long-term management costs for compensatory mitigation sites.  Providing adequate resources for long-term stewardship is essential to ensure that compensation sites are durable and provide lasting offsets for permitted losses.

• Implementing Financial Assurances for Mitigation Project Success.  In March 2016, the U.S. Army Corps of Engineers - Institute for Water Resources (IWR) released an updated copy of its financial assurances handbook.  The handbook discusses the key considerations associated with the different financial assurances that can be used to ensure that compensatory mitigation projects meet their performance standards.

• The Mitigation Rule Retrospective: A Review of the 2008 Regulations Governing Compensatory Mitigation for Losses of Aquatic Resources.  In November 2015, the U.S. Army Corps of Engineers and EPA released a report summarizing the progress made in implementing the 2008 Mitigation Rule, including analysis of trends in aquatic resource impacts and compensation from 2010 through 2014 and trends in mitigation banking and in-lieu-fee programs from the mid-1990s through 2014. View also the Report Factsheet.

• Watershed Approach Handbook: Improving Outcomes and Increasing Benefits Associated with Wetland and Stream Restoration Projects.  In September 2014, the Environmental Law Institute and The Nature Conservancy released a new handbook to advance the use of a watershed approach in the selection, design, and siting of wetland and stream restoration and protection projects, including projects required as compensatory mitigation for permitted activities.

• A Handbook for Prioritizing Wetland and Stream Restoration and Protection Using Landscape Analysis Tools.  In September 2013, the Environmental Law Institute released a new handbook that describes the range of tools used by wetland programs across the country to prioritize wetlands and streams for restoration and protection.

• National Wetland Compensatory Mitigation Study Design. In 2013, the Environmental Law Institute in partnership with a team of wetland scientists published a study design developed to help guide future evaluations of wetland compensatory mitigation project performance.

• Wetlands and Stream Mitigation: A Handbook for Land Trusts.  In September 2012, the Environmental Law Institute and the Land Trust Alliance released a handbook designed to provide land trusts with the tools they need to navigate the federal wetland and stream compensatory mitigation program and evaluate their engagement in the program.

• Additional Compensatory Mitigation Evaluations and Reports since 2000

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National Wetlands Mitigation Action Plan

On December 26, 2002, EPA and the Corps of Engineers announced the release of a comprehensive, interagency National Wetlands Mitigation Action Plan to further achievement of the goal of no net loss of wetlands. The goals and objectives of the National Mitigation Action Plan were incorporated into the 2008 Final Compensatory Mitigation Rule.

• National Wetlands Mitigation Action Plan (PDF)

• National Mitigation Action Plan Factsheet (PDF)

• Stakeholder Coordination - In 1999, the Federal agencies began hosting a series of stakeholder forums to gather information and opinions on the concerns and challenges of compensatory mitigation. These forums have brought together a diverse group of individuals representing the regulated community, environmental organizations, academia, non-governmental organizations, and mitigation providers. The first forum was held in Washington, DC, in 1999, to discuss draft guidance on in-lieu-fee mitigation. The second forum was held in Baltimore, Maryland, in October 2001. This meeting helped lead to the formulation of the National Wetlands Mitigation Action Plan. The third and fourth forums were held in Portland, Oregon (July 2003) and Tampa, Florida (September 2004) to discuss progress on Action Plan tasks and solicit input on future Action Plan tasks. The fifth forum was held in Washington, DC (May, 2006) to discuss the proposed compensatory mitigation regulations. View the stakeholder forum reports.