Menu
Log in


NC Association of Environmental Professionals

Log in

National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams

13 Jan 2025 8:21 AM | Erin Shanaberger (Administrator)

On January 8, 2025, The U.S. EPA and the U.S. Army Corps of Engineers (USACE) published the final National Ordinary High Water Mark (OHWM) Field Delineation Manual for Rivers and Streams. The National OHWM Manual is a non-mandatory resource that provides technical guidance for identifying aquatic resources that may be subject to regulatory jurisdiction under the Clean Water Act or Rivers and Harbors Act of 1899 (RHA). 

This manual presents a methodology for the identification and delineation of an OHWM. The manual describes regional differences, as well as addresses challenges in identifying an OHWM in a human-altered environment. Accompanied by a data sheet and field procedure, the manual is intended to guide users through a step-by-step process of identifying an OHWM to provide consistency, reliability, and defensibility in assessing surface water resources. Updates from the draft publication, which was first published in December 2022, include:

  • An updated data sheet to improve clarity and efficiency,
  • An added executive summary on the purpose of the manual,
  • An Updated list of definitions,
  • Added sections for indicators not discussed thoroughly in the draft manual,
  • Reorganized sections to follow the data sheet more closely, and 
  • Updated figures to reflect the changes in the manual and data sheet.

The final manual can be downloaded here and more information can be found on the USACE website .



NCAEP
PO Box #17512
Raleigh, NC 27619

NCAEP is registered 501(c)3 non-profit that promotes excellence in the environmental profession through events and scholarships.

Powered by Wild Apricot Membership Software