ERDC develops Regionalized Wetland Delineation Guidance

New Corps regulatory personnel learn to identify and delineate wetlands during a class exercise near Mobile, Ala

1 May 08 -- HANOVER, N.H. -- Researchers with ERDC-EL and ERDC-CRREL are working with more than 200 scientists from dozens of federal, state, and local agencies, universities, and private consulting firms nationwide to develop regional supplements to the Corps of Engineers’ 1987 wetland delineation manual.

According to project leader Dr. Jim Wakeley, EL, four of the 10 planned supplements have already been published, covering the entire western United States, except Hawaii. Four more regional supplements are in draft form and are undergoing external peer review, field testing and public comment.

Unless you moonlight as a real estate developer or have plans to fill in that “wet spot” on your land to build a new driveway and workshop, you may not be aware of the important role that the Corps plays in reducing the destruction of wetlands across the country and in protecting the benefits these wetlands provide to people.  Under the federal Clean Water Act, any company, agency or individual that wishes to build in wetlands must first apply for a permit from their local Corps district regulatory office.  Corps regulators will determine whether there are wetlands on the site that fall under Clean Water Act jurisdiction and what damages will be caused to them.  Before issuing the permit, they will work with the landowner to minimize or mitigate any unavoidable impacts to wetlands and the ecological services they provide.

Beneficial services provided by wetlands include water-quality improvement by trapping sediment, toxic chemicals, fertilizers, and pesticides before they enter our wells, lakes and streams.  Wetlands help reduce flooding along the nation’s rivers and streams, and they help protect stream banks, lake shores and coastlines from erosion and storm surge.  They provide habitat for wildlife, fish and shellfish, and help support valuable and diverse inland and coastal fisheries.

The first step in evaluating the potential impacts of a project to wetlands on a site is to identify the wetlands and delineate their boundaries.  Since 1987, Corps regulators have been aided in this task by the Corps of Engineers Wetlands Delineation Manual (hereafter called the Corps Manual), which was developed by EL.  However, the Corps Manual is now more than 20 years old and no longer represents the state-of-the-science in wetland identification.  Furthermore, the National Academy of Sciences recommended that the Corps Manual be “regionalized” to improve its sensitivity to regional variations in climate, landforms, geology, soils, hydrologic conditions, and plant and animal distributions.  The project to update and regionalize the Corps Manual is being directed by Wakeley with co-investigators Bob Lichvar, CRREL, and Chris Noble, EL, and is funded by Headquarters through the Wetlands Regulatory Assistance Program.

According to the Corps Manual, wetlands have three essential characteristics that can be used to identify them in the field:  hydrophytic vegetation, hydric soils, and wetland hydrology.  The new regional supplements provide vegetation, soil and hydrology indicators that are tailored to each region, along with guidance for delineating wetlands that are disturbed by human activities or are naturally difficult to identify.   Each supplement is developed by a regional working group of wetland-delineation experts and practitioners based on recent literature, the experience of working group members, and new studies performed under the project.  Draft regional supplements are reviewed by an interagency National Advisory Team and an independent peer-review team including private environmental consultants in the region, and each supplement is field tested by interagency teams according to a standard protocol.

The work would not be possible without the substantial contributions of personnel time, travel costs and other services from dozens of interagency partners.  Regional working groups typically consist of 20-30 experts from federal and state agencies and universities in the region.  So far, more than two dozen agencies have contributed members to the working groups, including the U.S. Environmental Protection Agency, USDA Natural Resources Conservation Service, U.S. Fish and Wildlife Service, U.S. Forest Service, Alaska Department of Environmental Conservation, Arkansas Highway and Transportation Department, Florida Department of Environmental Protection, Louisiana Department of Natural Resources, Maryland Department of the Environment, Minnesota Department of Environmental Quality, Ohio Environmental Protection Agency, Oregon Department of State Lands, Puerto Rico Department of Natural and Environmental Resources, Texas Department of Transportation, Washington Department of Ecology, and many others. 

To date, more than 200 agency, academic and private-sector experts have participated on working groups and peer-review teams.  Only about 60 of these have been Corps employees.  According to Wakeley, “The Corps is grateful for the significant contributions that various agencies and individuals have made to strengthen the methods we use to identify and delineate wetlands for Clean Water Act regulatory purposes.”