Updated Datasheet for the Identification of the Ordinary High Water Mark (OHWM) in the Arid West Region of the Western United States

摘要

The Ordinary High Water Mark (OHWM) is a method used to identify the lateral limits of non-wetland waters. Lichvar and McColley (2008) developed an OHWM delineation manual for ephemeral and intermittent streams in the Arid West. Their approach identified key hydrologic, geomorphic, and vegetation indicators useful in OHWM delineation. This technical note provides an updated datasheet to the manual. The datasheet has been simplified but still includes the overall field signatures and preliminary methods used to determine the OHWM. The datasheet now focuses on identifying the characteristics of each individual hydrogeomorphic floodplain unit and uses the differences between the floodplain units to identify the OHWM.