US Army Corps of Engineers
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Updated 2012 National Wetland Plant List available

Published May 15, 2012

CONCORD, Mass. – The U.S. Army Corps of Engineers, New England District announces the availability of the updated National Wetland Plant List (NWPL).


The NWPL plays a critical role in wetland determination under the Clean Water Act and Food Security Act. Wetlands are evaluated using three factors – soils, hydrology and vegetation.


The 2012 NWPL should be used in any wetland delineations performed after June 1, 2012. The 2012 NWPL may be used in delineations/determinations conducted prior to that date, and, for the purpose of clarity and accurate interpretation, should be referenced in delineation reports or regional supplement determination forms.


The NWPL is a list of plants with their updated nomenclature and their assigned indicator statuses. An indicator status reflects the likelihood that a particular plant occurs in a wetland or upland.


The lead responsibility to update the 1988 list was transferred from the U.S. Fish and Wildlife Service to the Corps of Engineers in 2006. The 2012 NWPL is the culmination of a six-year interagency process to update the 1988 National List of Plant Species That Occur in Wetlands. This national effort also has involved three other Federal agencies with legal responsibilities for wetlands: the U.S. Environmental Protection Agency (EPA), the U.S. Fish and Wildlife Service (FWS), and the Natural Resources Conservation Service (NRCS). This update represents the most complex and thorough evaluation of wetland plant species ratings since the inception of the 1988 list, and it allows for greater input across more professional institutions with increased public access to critical information.


The 2012 NWPL, background information, including previous names and indicator statuses, public comments and responses to the comments received in response to the Jan. 6, 2011 Federal Register notice, and the website citation may be found at:


The plant list can be downloaded from the website in its entirety, by region or by state.


The 2012 NWPL uses the best available scientific and technical information for improving precision in determining the vegetation factor when delineating upland/wetland boundaries for purposes of Section 404 of the Clean Water Act and the Wetland Conservation Provisions of the Food Security Act. It also provides a procedure for continual future scientific updates and public input as more data are gathered and analyzed.


The NWPL announcement was published in the May 9, 2012, Federal Register and is available at


The Corps will continue to accept suggestions on the 2012 NWPL. Suggestions may be submitted to Mr. Robert Lichvar, Director of the National Wetland Plant List ERDC/Cold Regions Research and Engineering Laboratory (CRREL), 72 Lyme Road, Hanover, NH 03755 or by email to


For more information on the USACE Regulatory Program, please visit:

Tim Dugan

Release no. 2012-045