Mitigation

Photo by Hayley Farrer

A fundamental precept of the USACE Regulatory Division is the Department of the Army's mitigation policy (33 CFR Part 320.4 (4)), which applies to all USACE Regulatory Permit authorizations, including general permits.

When the USACE Regulatory Division reviews a project that would require Department of the Army (DA) authorization, its evaluation includes a determination of whether the applicant has taken sufficient measures to mitigate the project’s likely adverse impact on the aquatic ecosystem. This includes avoiding, minimizing, and compensating for impacts to aquatic resources. If your project cannot avoid or sufficiently minimize impacts to waters of the United States (WOTUS), including wetlands, you must compensate for the impacts.

In a Memorandum of Agreement (MOA) signed February 6, 1990 between the USACE and the EPA, mitigation was defined as a sequential process of avoiding, minimizing, and compensating for adverse impacts to the aquatic ecosystem. The 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. Note: Portions of this MOA that concern the type and location of compensatory mitigation are superseded by the 2008 compensatory mitigation rulemaking.

• Avoid: Take all appropriate and practicable measures to avoid impacts to waters of the U.S., including wetlands. For example, choose sites that do not contain wetlands or design your project to avoid wetlands, where practicable.
• Minimize: Take all appropriate and practicable measures to minimize those adverse impacts to the ecosystem that cannot reasonably be avoided. For example, make your project as small as possible while still achieving its purpose. Use best management practices the prevent secondary impacts from your proposed work.
• Compensate: Implement appropriate and practicable measures to compensate for adverse project impacts to the aquatic ecosystem that cannot reasonably be avoided or further minimized. This step is called compensatory mitigation. The purpose of compensatory mitigation is to replace those aquatic ecosystem functions that would be lost or impaired as a result of a USACE-authorized activity.

All steps to avoid and/or minimize impacts to aquatic resources must be taken before proposing compensatory mitigation to offset project impacts. Methods of compensatory mitigation including restoration, establishment, enhancement and/or preservation of aquatic resources. They can be completed by purchasing credits at a Mitigation Bank or in-lieu fee program, or through permittee-responsible compensatory mitigation.

The key is to fill out and submit the Mitigation Statement clearly stating what steps you have taken to avoid and minimize impacts in the location and design of your project, and what compensatory mitigation you are proposing, or why you feel compensatory mitigation should not be required. The Mitigation Statement is required as part of a complete Individual Permit (IP) Application (33 CFR 325). The Corps of Engineers Regulatory Division is responsible for determining the need for compensatory mitigation as well as the nature and extent of compensatory mitigation on a case-by-case basis during the permit review process.

Mitigation requirements are outlined in the Code of Federal Regulations Compensatory Mitigation for Losses of Aquatic Resources Final Rule (33 CFR Part 332), commonly referred to as the Federal mitigation rule. The mitigation rule promotes consistency and predictability and improves ecological success of mitigation efforts through better site selection, use of a watershed approach for planning and project design, and use of ecological success criteria to evaluate and measure performance of mitigation projects.

The following links provide the regulatory references related to the Corps compensatory mitigation requirements:

• Corps Headquarters Final Compensatory Mitigation Rule Information
• Watershed Approach
• Watch an introductory video on Mitigation
• Compensatory Mitigation for Losses of Aquatic Resources; Final Rule (EPA)

In 1980, EPA finalized regulations that constitute the substantive environmental criteria used in evaluating activities regulated under Section 404 of the Clean Water Act under 40 CFR 230, entitled “SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL.”

The USACE, Regulatory Division must determine the nature and extent of the compensatory mitigation to be required based on what is practicable, environmentally preferable, and capable of compensating for the aquatic resource functions that would be lost as a result of the permitted activity (33 CFR 332.3(a)(1)). The nature and extent of the proposed mitigation must be commensurate with the scale and scope of the impacts.

Compensatory mitigation as defined in 33 CFR 332.2 is “the restoration (re-establishment or rehabilitation), establishment (creation), enhancement, and/or in certain circumstances preservation of aquatic resources for the purposes of offsetting unavoidable adverse impacts which remain after all appropriate and practicable avoidance and minimization has been achieved.” The objective of compensatory mitigation is to offset environmental losses resulting from discharges of dredged or fill material into waters of the United States. All compensatory mitigation will be for significant resource losses which are specifically identifiable, reasonably likely to occur, and of importance to the human or aquatic environment. Also, all mitigation will be directly related to the impacts of the proposal, appropriate to the scope and degree of those impacts, and reasonably enforceable (33 CFR 320.4(r)(2)).

33 CFR §332, the regulations that embody the Mitigation Rule, explains the different forms of compensatory mitigation and the considerations that must be made once it has been determined that compensatory mitigation is required. Further, the Mitigation Rule establishes a set of standards that all forms of compensation must satisfy to improve the planning, implementation, and management of compensatory mitigation projects. The Mitigation Rule specifies the components of a complete compensatory mitigation plan including assurances of long-term protection of compensation sites, financial assurances, and identification of the parties responsible for specific project tasks. It also emphasizes a watershed approach in selecting compensatory mitigation project locations, requires enforceable ecological performance standards tied to project objectives, and mandates regular monitoring for all types of compensation.

The Mitigation Rule (33 CFR §332) established a preference hierarchy for mitigation mechanisms (33CFR 332.3(b)) as follows:

1. Purchase of Mitigation Bank credits
2. Purchase of ILF Program tickets
3. Permittee Responsible Mitigation (PRM) under a watershed approach
4. On-site and/or in-kind PRM
5. Off-site and/or out-of-kind PRM

Mitigation banking is the restoration, enhancement, creation, and, in exceptional circumstances, preservation undertaken to compensate in advance for adverse impacts to the aquatic ecosystem. Mitigation banking may be appropriate when compensatory mitigation cannot be practicably achieved or would not be as environmentally beneficial at the impact site or a nearby site. The USACE, EPA, National Resources Conservation Service, United States Fish and Wildlife Service, and National Marine Fisheries Service Federal Mitigation Banking Final Policy (Federal Register: November 28, 1995 (Volume 60, Number 228)) guidance regarding the establishment, use, and operation of mitigation banks for the purpose of providing compensation for adverse impacts to wetlands and other aquatic resources is provided to clarify the manner in which mitigation banks may be used to satisfy mitigation requirements of the CWA Section 404 permit program and the wetland conservation provisions of the Food Security Act (FSA) (i.e., Swampbuster provisions). Recognizing the potential benefits mitigation banking offers for streamlining the permit evaluation process and providing more effective mitigation for authorized impacts to wetlands, the agencies encourage the establishment and appropriate use of mitigation banks in the Section 404 and Swampbuster programs.

It is important to note that mitigation banks are established by third parties and the USACE does not determine the price of the credits.

RIBITS

RIBITS was developed by the U.S. Army Corps of Engineers with support from the Environmental Protection Agency 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. You may also Contact USACE regarding mitigation banks and in-lieu fee programs that may be appropriate for your specific project.

Mitigation banks and in-lieu fee programs must prepare a mitigation plan including the items in paragraphs (c)(2) through (c)(14) of this 33 CFR 332.4(c) for each separate compensatory mitigation project site. For mitigation banks and in-lieu fee programs, the preparation and approval process for mitigation plans is described in §332.8.

If Permittee Responsible Mitigation (PRM) compensatory mitigation is required, you must submit a mitigation plan. There are 12 required components in every mitigation plan. The mitigation rule (33 CFR 332.4(c)) describes these 12 components in detail:

Although not required, assistance from a qualified environmental consultant may be beneficial in developing a comprehensive and acceptable mitigation plan. All mitigation plans require USACE Regulatory Division approval.

Flexibility is crucial in Alaska because of widespread wetlands and other waters with relatively high ecological integrity, and few opportunities for compensation. The Regulatory Division, Alaska District had created the Alaska District Compensatory Mitigation Thought Process dated September 18, 2018, and revised on April 8, 2023, as a tool to evaluate compensatory mitigation requirements.  

The Compensatory Mitigation Considerations for the U.S. Army Corps of Engineers, Alaska District Regulatory, finalized in January 2025, replaces and supersedes the Alaska District Compensatory Mitigation Thought Process. The ‘Considerations’ document supplies the Alaska District with the statutory support and rationale for determining when to require compensatory mitigation and what factors should be considered when reviewing plans for compensatory mitigation. Specifically, the document:

1) briefly describes compensatory mitigation;

2) provides considerations for determining whether project impacts should require compensatory mitigation;

3) provides considerations for determining what approaches to compensatory mitigation are appropriate and practicable; and

4) addresses aspects of documenting decisions regarding compensatory mitigation.