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Providing Region-Specific Methods for Wetlands Delineation

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Under Section 404 of the Clean Water Act to restore and maintain the chemical, physical, and biological integrity of the waters of the United States, permits may be issued for discharge of dredged or fill materials into the waters of the United States including wetlands.

The Corps of Engineers Wetlands Delineation Manual (1987) provides technical guidance and procedures, from a national perspective, for identifying and delineating wetlands. Following recommendations from the National Academy of Sciences to increase the sensitivity of wetland delineation methods based on regional wetland characteristics, Regional Working Groups consisting of local experts from the US Army Corps of Engineers, US Environmental Protection Agency, US Fish and Wildlife Service, US Natural Resources Conservation Service and state agencies developed wetland delineation procedures to increase regional specificity.

Led by the Corps Regulatory Program and ERDC Environmental Laboratory (EL) in Vicksburg, Miss., Regional Supplements to the 1987 Wetlands Delineation Manual provides users with region-specific methods and guidelines for wetland delineation pursuant to the Clean Water Act.

More Reliable Delineation Guidance

Regional differences in climate, hydrologic and geologic conditions, and other wetland characteristics require area-specific delineation methods to determine whether wetland criteria are present. By accounting for regional variations in hydric soils, hydrophytic vegetation, and wetland hydrology among wetlands across the United States, Regional Supplements to the 1987 Wetlands Delineation Manual improve the accuracy and efficiency of wetland delineation procedures.

Regional Supplements include:

  • Alaska
  • Arid West
  • Atlantic & Gulf Coastal Plain 
  • Caribbean Islands    
  • Eastern Mountains and Piedmont        
  • Great Plains
  • Hawaii and Pacific Islands        
  • Mid-West
  • Northcentral and Northeast        
  • Western Mountains, Valleys, and Coast 

Applications in the Field

The Regional Supplements are designed for use with the current version of the Corps Manual and all subsequent versions, reflecting the most current science available. In addition to identifying wetlands in support of the USACE Regulatory Program mission to protect the Nation’s aquatic resources, the Regional Supplements are adopted for use nationwide by all Federal, state and independent agencies for delineating wetlands.


Regional Supplements to the Corps Delineation Manual are available at: http://www.usace.army.mil/Missions/CivilWorks/RegulatoryProgramandPermits/reg_supp.aspx.

ERDC Points of Contact
Questions about the Regional Supplements?
Contact: Sally Yost
Email: Sally.L.Yost@usace.army.mil
Phone: 601-634-3622