Ordinary High Water Mark (OHWM) Research, Development, and Training

Improving Corps regulatory practices

Engineer Research and Development Center
Published July 9, 2014
Crossing the channel to begin surveying.

Dr. Gabrielle David surveying a cross section on Hubbard Brook in New Hampshire as part of a national study to develop the first national field delineation manual for identifying the OHWM. This survey was conducted during the summer of 2017. This stream represents steeper boulder/cobble bedded channels in forested systems.

Total station set-up on point bar; looking upstream.

A total station being used to survey an incised channel in North Dakota (Antelope Creek) as part of a multi-year national study to develop the first national field delineation manual for identifying the OHWM. This picture was taken in July 2017. This stream represents incised channels on the plains in a watershed dominated by agriculture and livestock.

The National Technical Committee for the Ordinary High Water Mark meeting in Boise, Idaho to discuss regional variations in OHWM and difficulties in identifying OHWM throughout the U.S.

The National Technical Committee for the Ordinary High Water Mark meeting in Boise, Idaho to discuss regional variations in OHWM and difficulties in identifying OHWM throughout the U.S. The NTC-OHWM is an interagency committee that includes ERDC CRREL, USACE Regulators, EPA, and academics. This meeting in Idaho took place in August of 2018. The photograph shows the committee members walking along Long Tom Creek.

Dr. David is standing at the level of the OHWM and pointing towards evidence along the banks of the Willamette River.

Dr. Gabrielle David discussing the location of the OHWM on the Willamette River in Oregon during the Portland District OHWM Field Delineation training course. Dr. David is standing at the level of the OHWM and pointing towards evidence along the banks of the river. This course took place in July 2019.

OHWM field training course in Rock Island District with USACE Regulators.

OHWM field training course in Rock Island District with USACE Regulators. Dr. Gabrielle David is discussion the location of the OHWM along this small non-perennial stream. The course took place in July of 2018.

OHWM Training

ERDC researchers demonstrating OHWM delineation procedures during a two-day training workshop for the Los Angeles Corps Regulatory District. This training helps to improve the accuracy and consistency of OHWM delineation practices.

Mission Creek OHWM Survey

ERDC researchers surveying OHWM indicators at Mission Creek near Desert Hot Springs, CA. This work supports the development of technical guidance aimed at improving Corps regulatory practices.

The ordinary high water mark (OHWM) defines the boundaries of aquatic features for a variety of federal, state, and local regulatory purposes.  Under the Clean Water Act, the OHWM defines the lateral limits of federal jurisdiction for non-tidal waters of the U.S. in the absence of adjacent wetlands (including Section 404, which regulates the discharge of dredge and fill material into waters of the U.S.). Additionally, under Sections 9 and 10 of the Rivers and Harbors Act of 1899, the OHWM defines the lateral limits of federal jurisdiction for non-tidal traditional navigable waters of the U.S.  Accurate, consistent, and efficient OHWM delineation practices are thus essential to proper and effective implementation of these laws and regulations by the U.S. Army Corps of Engineers Regulatory Program and other agencies.  However, OHWM delineation can be challenging in light of the spatial and temporal dynamics of inland waters and the various anthropogenic impacts that compound this complexity. 

ERDC works with the Corps Regulatory Program, other federal agencies, and the academic community to develop regional and national OHWM delineation standards and procedures and to improve OHWM delineation practices across the country.  Research scientists test and validate the field indicators and methods used in OHWM delineations and explore new tools, techniques, and resources to improve the accuracy, consistency, and efficiency of OHWM delineation practices.  These efforts have resulted in OHWM delineation manuals and other technical resources that support both the Corps Regulatory Program and the regulated public.  This work is largely funded through the Corps Wetlands Regulatory Assistance Program (WRAP). 


Regional Delineation Manuals

Western Mountains, Valleys, and Coast: A Guide to Ordinary High Water Mark (OHWM) Delineation for Non-perennial Streams in the Western Mountains, Valleys, and Coast Region of the United States (Mersel and Lichvar 2014)

Arid West: A Field Guide to the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States (Lichvar and McColley 2008) 


Supporting Research and Technical Reports

Hydrologic Analysis of Field Delineated Ordinary High Water Marks for Rivers and Streams (Hamill and David 2021)

Synthesizing the Scientific Foundation for Ordinary High Water Mark Delineation in Fluvial Systems (Wohl et al. 2016)

The Benefits and Limitations of Hydraulic Modeling for Ordinary High Water Mark Delineation (Gartner et al. 2016)

Hydrologic Modeling and Flood Frequency Analysis for Ordinary High Water Mark Delineation (Gartner et al. 2016)

Integrating Hydrologic Modeling, Hydraulic Modeling, and Field Data for Ordinary High Water Mark Delineation (Gartner et al. 2016)

Occurrence and Distribution of Ordinary High Water Mark (OHWM) Indicators in Non-perennial Streams in the Western Mountains, Valleys, and Coast Region of the United States (Mersel et al. 2014)

A Review of Land and Stream Classifications in Support of Developing a National Ordinary High Water Mark Classification (Mersel et al. 2014)

Channel Classification across Arid West Landscapes in Support of OHW Delineation (Lefebvre et al. 2013)

Survey of OHWM Indicator Distribution Patterns across Arid West Landscapes (Lefebvre et al. 2013)

Ordinary High Flows and the Stage-Discharge Relationship in the Arid West Region (Curtis et al. 2011)

Vegetation and Channel Morphology Responses to Ordinary High Water Mark Discharge Events in Arid West Stream Channels (Lichvar et al. 2009)

Review and Synopsis of Natural and Human Controls on Fluvial Channel Processes in the Arid West (Field and Lichvar 2007)

Distribution of Ordinary High Water Mark (OHWM) Indicators and Their Reliability in Identifying the Limits of "Waters of the United States" in Arid Southwestern Channels (Lichvar et al. 2006)

Regulatory Guidance Letter: Ordinary High Water Mark Identification (USACE 2005)

Review of Ordinary High Water Mark Indicators for Delineating Arid Streams in the Southwestern United States (Lichvar and Wakeley 2004)


Contact

ERDCinfo@usace.army.mil  |  603-646-4307
Updated 25 August 2020

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