For 10 years, the U.S. Army Engineer Research and Development Center’s (ERDC) Cold Regions Research and Engineering Laboratory (CRREL) has led research on the development of a national manual and data sheet to identify the Ordinary High Water Mark (OHWM) across the United States.
The national manual was released as an interim draft and describes the OHWM, which is used to define the boundaries of aquatic features for a variety of federal, state and local regulatory purposes.