The U.S. Army Corps of Engineers (USACE) and the U.S. Environmental Protection Agency (EPA) 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 are soliciting public comments on this Interim Draft. The Interim Draft of the National OHWM Manual does not imply or represent a change to the definition of “ordinary high water mark” (OHWM) or “Waters of the U.S.” nor does it change existing guidance related to the OHWM (e.g., Regulatory Guidance Letter No. 05-05). Instead, the Interim Draft of the National OHWM Manual provides draft technical guidance for identifying aquatic resources that may be subject to regulatory jurisdiction under Section 404 of the Clean Water Act (CWA) and/or Sections 9 and 10 of the Rivers and Harbors Act of 1899 (RHA), by providing a standard process, uniform datasheets, and unified field procedures to identify and delineate the OHWM of rivers and streams located throughout the Nation. The Interim Draft of the National OHWM Manual was developed by the National Technical Committee for OHWM, which includes experts from Federal agencies and academia. The document provides a scientifically based, rapid framework to support OHWM identification and delineation in a consistent, robust, repeatable, and defensible way.