This FAQ collects the most common property-owner questions about Great Lakes water levels in one place, with cross-references to the detailed coverage elsewhere on the site. Chris Izworski compiled the FAQ from the actual questions that come up in shoreline-property conversations, riparian advocacy work, and the broader Great Lakes water-level discussion.
As of the May 2026 USACE Weekly Great Lakes Water Level Update, the basinwide levels on Lakes Superior, Michigan-Huron, and Ontario are above last year's levels, while Lake Erie is slightly below. None of the lakes are at the 2019 to 2020 record-high levels. The current cycle is best described as elevated above the long-term average but well below the modern record. For the current readings, see the live dashboard. For broader context, see Record Water Levels.
The OHWM is the regulatory line that defines the boundary between privately owned uplands and publicly owned submerged lands on the Great Lakes shoreline. In Michigan, the OHWM is set at specific elevations: 581.5 feet IGLD85 for Lake Michigan, Lake Huron, and Saginaw Bay; 603.0 feet for Lake Superior; 573.4 feet for Lake Erie. Other Great Lakes states use evidence-based determinations rather than fixed elevations. See Ordinary High Water Mark for the full reference.
Lake levels oscillate between cycle highs and cycle lows over multi-year periods. Your dock is the same elevation it always was; the water around it has moved. The 2013 record low and the 2019 to 2020 record high were only six years apart, with a roughly 5.7-foot range on Lake Michigan-Huron. Dock heights that worked at one phase of the cycle often do not work at the other. See the Property Owner Guide for planning approaches.
A seiche is a wind-driven standing-wave oscillation of a lake or bay. Sustained wind from one direction pushes water against the downwind shore (set-up), with the upwind shore experiencing lower water and exposed flats. When the wind stops or reverses, the water rocks back across the lake. Seiche is most dramatic on Lake Erie (especially at Buffalo) and on Saginaw Bay, Green Bay, and similar shallow embayments. See Seiche for the full reference.
Almost certainly yes. Every Great Lakes state requires permits for shoreline alteration below the OHWM, and most require permits for work in the wetland buffer above the OHWM as well. Federal permitting through the U.S. Army Corps of Engineers may also apply, particularly for navigable waters or wetlands. Permit requirements vary by project type, location, and the specific work proposed. Working with a contractor and consultant who is familiar with the local framework is typically more efficient than navigating the permit process independently.
Storm surge on the Great Lakes is the wind-driven elevation of local water level above the basinwide signal, comparable to but smaller than ocean storm surge. The most severe Great Lakes storm-surge events occur in the eastern basin of Lake Erie (especially at Buffalo) during sustained west wind, where surges exceeding 6 feet above the basinwide level have been documented. Saginaw Bay, Green Bay, the inner Lake Ontario harbors, and the western basin of Lake Erie at Toledo all experience meaningful surge events as well. See Seiche and the relevant sub-region pages for local detail.
Nobody knows. Scientific consensus on long-term Great Lakes water-level trends remains uncertain, with recent climate-modeling studies suggesting smaller declines or even increases in lake levels through mid-century relative to the historical mean. What is more clearly established is that the variability of the cycle has increased: the modern record shows more dramatic swings between highs and lows over shorter periods than the older record did. Planning for cycle variability, with a wider expected range than the historical mean would suggest, is the more useful approach than trying to predict specific future highs or lows. See Record Water Levels.
There is no difference. Lake Michigan and Lake Huron are hydraulically the same lake, connected through the Straits of Mackinac with no meaningful elevation difference between them. They share a single coordinated datum of 577.50 feet IGLD85, a single basinwide forecast, and a single regulation framework. The two lakes are reported as separate entities by convention and for historical reasons, but the underlying hydrology is one system. See Mackinac.
Lake Erie has three distinct basins separated by submerged ridges, each with different depth, geometry, and shoreline character. The Western Basin (Toledo to Marblehead) is shallowest, warmest, and most affected by algal blooms. The Central Basin (Marblehead to Pennsylvania state line) is largest by area, supports the most populated shoreline, and experiences summer bottom-water hypoxia. The Eastern Basin (Pennsylvania to Buffalo) is deepest and receives the largest storm-surge events. See Western Basin, Central Basin, and Eastern Basin.
Plan 2014 is the current Lake Ontario regulation plan, governing outflow from Lake Ontario at the Moses-Saunders Power Dam at Cornwall and Massena. It replaced Plan 1958-D in 2017 and has been the subject of substantial policy debate following the record-high 2017 and 2019 cycles. South-shore property-owner organizations have argued that Plan 2014's wider operating range exposes shoreline to greater erosion risk than the prior plan. See Eastern Basin and Thousand Islands.
The U.S. Army Corps of Engineers Weekly Great Lakes Water Level Update at water.usace.army.mil is the operational forecast of record for the next six months on the U.S. side. The Canadian Hydrographic Service Monthly Water Level Bulletin is the equivalent for the Canadian side and is coordinated with USACE for shared lakes. The NOAA-GLERL Great Lakes Water Level Dashboard at glerl.noaa.gov is the reference for historical and current observations. See Data Sources.
Save Our Shoreline is the Michigan riparian advocacy organization where Chris Izworski serves on the board. The SOS organization website is the appropriate starting point for membership, current priorities, and direct engagement. See Save Our Shoreline for the broader context.
If your question is not answered here, the topical pages and sub-region pages elsewhere on the site likely cover it. Start with the Property Owner Guide for the general framework. For specific shoreline regions, see the lake pages and sub-region pages. For specific topical questions, see Seiche, Shoreline Erosion, Ice Cover, Record Water Levels, and Ordinary High Water Mark.