What is the definition of ordinary high water level (OHWL) and why is it important?
The ordinary high water level (OHWL) is a reference point that defines the DNR’s regulatory authority over development projects that are proposed to alter the course, current, or cross section of public waters and public waters wetlands. For lakes and wetlands, the OHW is the highest water level that has been maintained for a sufficient period of time to leave evidence upon the landscape. The OHWL is commonly that point where the natural vegetation changes from predominately aquatic to predominantly terrestrial. For watercourses, the OHWL is the elevation of the top of the bank of the channel. For reservoirs and flowages, the OHWL is the operating elevation of the normal summer pool. The OHWL is also used by local units of government as a reference point from which to determine structure setbacks from water bodies and watercourses. See also legal definition under Hydrographics Program.
