Ordinary high water mark

From Wikipedia, the free encyclopedia

Floodplain of the Lynches River, Johnsonville, South Carolina. The sharp distinction in shading on the tree trunks shows the ordinary high water mark.

Ordinary high water mark refers to the highest level reached by a body of water that has been maintained for a sufficient period of time to leave evidence on the landscape. It may be indicated by destruction of terrestrial vegetation, the presence of marks on trees (see image at right) or debris deposits. It is usually the point at which natural vegetation shifts from predominately hydrophytic (water-dependent) species to terrestrial species.

The U.S. state of Wisconsin has a public trust doctrine that makes rivers and lakes public resources held in trust by the state as the common property of all citizens. In the case of lakes, the ordinary high water mark establishes the boundary between public jurisdiction and private property.