Updated Regional Wetland Delineation Manual Released

April 2012Articles In the Zone

The U.S. Army Corps of Engineers, Pittsburgh District, announced the availability of the Regional Supplement to the Corps of Engineers Wetland Delineation Manual : Northcentral and Northeast Region, Version 2.0. It provides technical guidance and procedures for identifying and delineating wetlands that may be subject to regulatory jurisdiction under Section 404 of the Clean Water Act or Section 10 of the Rivers and Harbors Act. Version 2.0 replaces the “interim” version, which was published in October 2009.

The development of regional supplements is part of a nationwide effort to address regional wetland characteristics and improve the accuracy and efficiency of wetlanddelineation procedures. The supplement is applicable to the Northcentral and Northeast Region, which consists of all or portions of 15 states: Connecticut, Illinois, Indiana, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont and Wisconsin.

The following changes were incorporated into Version 2.0 of this supplement:

  1. Wording and organizational changes have been made throughout the document in an attempt to improve its clarity and consistency with other regional supplements. Several web links have been updated.
  2. In Chapter 3, some new photos of hydric soil indicators have been added. In addition, the wording of several hydric soil indicators has been updated to conform to Version 7.0 of the National Technical Committee for Hydric Soils (NTCHS) field indicators. In particular, see hydric soil indicators A5, A11, A12, S6, S7, S8, S9 and others for updated wording. Also, indicator A16 Coast Prairie Redox remains in the section addressing hydric soil indictors for problem soils.
  3. An addition has been made to the section on Hydrology and Growing Season (page 79) based on deliberations of regional working group members and the National Technical Committee for Wetland Vegetation.
  4. The section defining where to start soil observations (page 40) was updated to include the use of indicator S3.
  5. Soil indicator TF2 – red parent materials has been removed and replaced by F21 – red parent material. This indicator has been approved for testing nationwide. Changes are based on National Technical Committee for Hydric Soils determinations.
  6. Definition of DBH added to glossary based on working group comments. “Diameter at breast height (DBH). A standard method of expressing the diameter of the trunk or bole measured at 1.37 meters (4.5 ft) above the ground. On sloping ground, measurements should be taken from the uphill side of the trunk. If the DBH point falls on a swelling in the trunk measure the girth below the swelling at the point where the diameter is smallest.”

The Corps will continue to accept comments/suggestions and new data on this supplement.