Army Corps of Engineers: Determinations That Projects Do Not Need Environmental Mitigation Should Be Clarified

The U. S. Army Corps of Engineers plans, constructs, and maintains water resources projects across the country. For Civil Works projects submitted to Congress for authorization, federal statute requires the Corps to report its plans for environmental mitigation.

In 2020-2025, the Corps determined that mitigation plans were needed for 22 projects and not needed for 52 projects. For the 52 projects without mitigation plans, reports submitted to Congress and supporting feasibility reports generally lacked clear documentation of the Corps's determination that no mitigation was needed and the basis for that determination. The Corps officials acknowledged that they have not consistently documented their determinations that no mitigation is needed in a clear format, which could be beneficial for Congress and the public. This lack of clear documentation may lead to inadequate assurance that authorization of projects without mitigation will not result in undue impacts on fish and wildlife and ecological resources. The Water Resources Development Act of 2022 includes provisions for GAO to review Corps plans to mitigate fish and wildlife losses resulting from Civil Works projects.

GAO's review of laws, regulations, and guidance relevant to Civil Works mitigation activities found that the Corps's mitigation plans and determinations that mitigation is not necessary are not consistently documented. The review of Civil Works projects submitted for authorization in 2020-2025 found that the reports submitted to Congress and supporting feasibility reports generally lacked clear documentation of the Corps's determinations that no mitigation was needed and the basis for those determinations. The lack of clear documentation may lead to inadequate assurance that authorization of projects w