Where is the Ordinary Highwater Mark

Where is the Ordinary Highwater Mark

The Ordinary High-Water Mark (OHWM) is an important reference point for an inland lake property owner. The OHWM is not always clear or obvious, and in this article we will spend some time learning what the OHWM is, where to find it on inland lakes in Michigan and whether the OHWM is established “by law” or not.

Michigan statutory law defines the OHWM as: “[t]he line between upland and bottomland that persists through successive changes in water levels, below which the presence and action of the water is so common or recurrent that the character of the land is marked distinctly from the upland and is apparent in the soil itself, the configuration of the surface of the soil, and the vegetation.” MCL 324.30101.

Put more simply, the OHWM is the boundary between water and land. For common inland lake landowner projects such as shoreline improvements (sanding), seawalls and permanent docks, the landowner should know the OHWM and may be required to identify it on their permit application. Determining the OHWM is not limited to only “water side” improvement projects. If a riparian landowner has wetlands present on their property, the projects they might undertake on those wetland portions (for example, installing a driveway to the public highway) and the level of permitting required to work in those wetlands may be affected by the wetlands distance from the OHWM.

The OHWM is a reference to the “place” where water and land most frequently meet. Note that where the water line or lake level is on any given day is not necessarily the OHWM for the lake. For example, as I write this article, September has incurred some unusually heavy rains, causing spikes in inland lake and river levels. The OHWM does not rise as a result of temporary or seasonal variations in water level. While there are many factors that can go into determining the OHWM, slope, change in soil/substrate and lack of upland vegetation are good starting points to approximate the area.

As I previously referenced, some inland lakes have their level set “by law.” On an inland lake that has a level established by law, it means the high established level. This “legal lake level” is usually established by a court action between the county drain commissioner and the county circuit court. The result of this legal action is an elevation above sea level that sets the level for that lake. Legal lake level lakes typically have their water levels controlled by a dam or other device.

In Oakland County, for example, many of the most popular lakes have legal lake levels. Oakland County publishes weekly “lake level reports” with the current water level, as well as the OHWM for those lakes.

If you have questions about determining where the OHWM is for your future project, we’re happy to help.