Senecaville Lake

Public Review Documents & Approved Review Plans



Published Dec. 2, 2022
Expiration date: 12/1/2023

USACE and EPA (Agencies) jointly announce the availability of the Interim Draft of the National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams (National OHWM Manual) and its accompanying data sheet. The Interim Draft National OHWM Manual provides draft technical guidance for identifying and delineating the OHWM using a scientifically supported, rapid framework. The Agencies are requesting comments and feedback from the public and practitioners on the Interim Draft of the National OHWM Manual via the public notice linked below. Following the public comment period and additional field testing, comments and feedback received from the public and practitioners will be utilized to further refine the Interim Draft of the National OHWM Manual for clarity, consistency, and technical accuracy. The one-year testing and comment period ends on December 1, 2023.


A final version of the National OHWM Manual is anticipated to be published during 2024.


During the period while the OHWM Manual is an interim draft, OHWM identification and/or delineation for official USACE Regulatory purposes should continue in accordance with the applicable OHWM definition in the Federal regulations, Regulatory Guidance Letter 05-05, and any applicable USACE district policies. However, USACE Regulatory staff are encouraged to test the Interim Draft of the National OHWM Manual and provide comments and feedback by emailing


Comments regarding the following specific topics would be especially useful:

  • Indicators that were particularly useful or not useful in identifying the OHWM.
  • Regional differences in the applicability of specific field indicators.
  • Implementation of the Weight of Evidence approach to assemble, evaluate, and integrate lines of evidence to support OHWM identification and delineation.
  • Problem situations encountered and possible approaches for addressing them.
  • Additional remote sensing data or techniques which may be utilized to support OHWM identification and delineation.
  • Usefulness of the supporting examples to clarify and inform identification of indicators and lines of evidence in the field.
  • Usefulness, usability, and clarity of the OHWM datasheet and its accompanying instructions and field procedures.


Link to HQ Announcement and Public Notice:

Link to Interim Draft of the National OHWM Manual:

Link to additional information on the research supporting OHWM identification and delineation:


The National OHWM Manual does not imply or represent a change to the definition of OHWM found at 33 CFR 328 or 33 CFR 329 nor does it change existing policy guidance related to the OHWM found in RGL No. 05-05. Instead, it provides a standardized process, a uniform datasheet, and unified field procedures to identify and delineate the OHWM of rivers and streams located throughout the Nation. The National OHWM Manual will help to promote accurate, consistent, and efficient OHWM delineation practices by practitioners and by USACE and other agencies. OHWM delineation can occasionally be challenging due to factors such as spatial and temporal dynamics of inland waters and anthropogenic impacts that can mask or confound shoreline field indicators. Use of the National OHWM Manual is intended to result in more timely, consistent, and predictable identification and delineation of the OHWM across the Nation.


Led by the U.S. Army Engineer Research and Development Center (ERDC), the National Technical Committee for OHWM (NTC-OHWM) authored the National OHWM Manual, and consists of ERDC researchers, practitioners from USACE Regulatory district and division offices, policy experts from USACE’s Institute for Water Resources, technical and policy experts from the EPA, and technical experts from academia. Training on the National OHWM Manual was held for USACE staff in Vicksburg, MS; Louisville, KY; and Los Angeles, CA during 2022, with additional in-person training for USACE staff being held in Jacksonville, FL and Huntington, WV in 2023. Virtual training materials will be developed by ERDC and the NTC-OHWM in the coming months and will provide USACE, its Federal and State partners, and the public with on-demand training opportunities on the National OHWM Manual. ERDC will also be releasing a Technical Note later in 2022, which will provide USACE and the public with additional tools and technologies to support OHWM delineations via rapid remote sensing techniques.

Chick Lock

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