Synthesis of Information Related to Highway Practices. Topic 57-17. Wetland and Waterway Mitigation Banking for State DOTs

Mitigation banking is a common practice used by state departments of transportation (DOTs) throughout the United States to offset impacts to regulated wetlands and waterways. A mitigation bank is a wetland or stream area that has been restored, established, enhanced, or preserved for the purpose of providing compensation for unavoidable impacts on aquatic resources permitted under Clean Water Act Section 404 or similar state/local wetland regulations. According to the 2008 Federal Mitigation Rule, mitigation banks form one of three potential mechanisms for providing compensatory mitigation, with permittee-responsible mitigation (PRM) and in-lieu fee (ILF) programs.  The use of mitigation banking tends to reduce permit processing times, reduce temporal lag between aquatic impacts and mitigation-site ecological function, and increase the likelihood of mitigation success. Federal regulations establish a preference for using mitigation bank credits over other compensation mechanisms; however, the utilization of mitigation banks remains varied relative to ILF programs and PRM. Understanding the proportion of mitigation achieved in each state by mitigation banking relative to ILF and PRM routes, along with the success rates and major causal factors driving these patterns, would help to guide future efforts to increase the use of banking as the most effective form of achieving mitigation. OBJECTIVE: The objective of this synthesis is to document current state DOT practices for utilizing wetland and waterway mitigation banking to offset impacts to aquatic resources. Information to be gathered includes (but is not limited to): Documented benefits and challenges of using mitigation banking; Projects that use mitigation banks versus other mitigation programs; Process for selecting mitigation type (e.g., permittee-responsible mitigation, in-lieu fee programs, or mitigation banks); Strategies used by state DOTs to increase the availability of mitigation banks; and Mitigation banks that are privately owned versus state DOT assets or that are turned over to partner state resource agencies. Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified. 

• Record URL:
  • http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5994

Language

• English

Project

• Funding: $65,000.00
• Contract Numbers:

  20-05/Topic 57-17

• Sponsor Organizations:

  National Cooperative Highway Research Program (NCHRP) Synthesis

  Transportation Research Board
  500 Fifth Street, NW
  Washington, DC    20001

  American Association of State Highway and Transportation Officials (AASHTO)

  444 North Capitol Street, NW
  Washington, DC  United States  20001

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Project Managers:

  Hutchins, Mark

• Start Date: 20241001
• Expected Completion Date: 20260101
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: State departments of transportation; Waterways; Wetland conservation; Wetlands
• Identifier Terms: Wetlands Mitigation Program
• Subject Areas: Environment; Highways;

Filing Info

• Accession Number: 01972867
• Record Type: Research project
• Source Agency: Transportation Research Board
• Contract Numbers: 20-05/Topic 57-17
• Files: TRB, RIP
• Created Date: Nov 25 2025 5:09PM