The National Academies

ACRP 02-70 [Completed]

Wetland Mitigation--A Guidebook for Airports

  Project Data
Funds: $400,000
Research Agency: Smart Associates Environemtnal Consulting
Principal Investigator: Glenn Smart
Effective Date: 9/28/2016
Completion Date: 10/15/2018


Current and planned airport construction, expansion, and safety improvements often result in the unavoidable loss of wetlands, as many airports were constructed in or adjacent to wetlands. In addition, the size and scale of airports and supporting infrastructure is extensive, which has made it difficult to completely avoid impacting wetlands. Passage of the Clean Water Act in 1972 led to the regulation of impacts on wetland resources; and Executive Order 11990, issued in 1977, required federal agencies to avoid and minimize wetland impacts where possible. In 1989, the United States government established a “no net loss” policy (Army-EPA Memorandum of Agreement on Mitigation Under the § 404 Program). The goal of the policy is to compensate for the loss of wetland resources through mitigation.  In 2008 the U.S. Army Corps of Engineers (USACE) and the U.S. Environmental Protection Agency (USEPA) jointly issued the “Compensatory Mitigation for Losses of Aquatic Resources; Final Rule.” This rule established the national policy on compensatory wetland mitigation; however, the implementation of this rule continues to be affected by varying regional interpretation and by differing state laws. In addition, meeting the regulatory requirements for wetland mitigation while maintaining safe airport operations can be challenging because of the link to potential wildlife hazards. More detailed information on the techniques and strategies of wetland mitigation compatible with aviation operations would benefit both airports and appropriate federal and state agencies in implementing effective forms of mitigation. 


The objective of this research was to prepare a Guidebook to facilitate implementation of effective wetland mitigation in support of airport expansion and development, including safety-related improvements. In preparing the Guidebook, the research addressed a broad range of issues:
  • Concerns over the creation of potential wildlife hazards;
  • Existing requirements, which may or may not be conflicting;
  • Impact to existing and future airport development; and
  • Airport considerations of cost and logistics in developing mitigation and related life-cycle obligations.

The research plan was divided into two phases, and each phase addressed a detailed set of work tasks::
  1. A description of proposed deliverables for each task or group of tasks along with a detailed project schedule;
  2. A suggested schedule for conference calls with the ACRP panel to review and discuss progress and interim work products;
  3. An interim report prepared at the conclusion of Phase I describing work done as part of Phase I tasks (the interim report will also include an updated work plan, a schedule for Phase II, and an annotated outline of the final product); and
  4. An interim meeting with the ACRP panel to review the interim report and to authorize Phase II.
Phase I

Reviewed current wetland mitigation laws, regulations, and policies, along with mitigation techniques and issues facing airports regarding site selection, design, implementation, and maintenance of wetland mitigation sites.

Phase II

Developed the components of the Guidebook including the proposed wetland mitigation strategies—current and potential, and evaluated applicability to airport mitigation requirements. 
STATUS The final report has been published (ACRP Report 198), including an Executive Summary, A Guidebook, a PowerPoint presentation, and additional Appendices. The Executive Summary is identified as Volume 1; the Guidebook as Volume 2.

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