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High water

What causes higher water levels?

Water levels on the Great Lakes are cyclical with periods of low and high water, with each period lasting for several years depending on the amount of precipitation, runoff and evaporation that occurs. Higher waters can cause stronger, faster currents (especially around river outlets and piers), deeper and colder water, unpredictable conditions and more debris floating under the water's surface.

In 2020, the Great Lakes were at their highest levels in more than 30 years, and that means there are increased safety concerns when swimming and boating, potential property damage along shorelines, submerged docks and piers and other concerns.

Great Lakes water level data »

EGLE high water information »

Boat speed and no-wake restrictions

Local watercraft controls and restrictions are in place to protect people and property. Wakes – the flow of water caused by a boat or something else moving through the water can cause overflow onto land or docks, especially during high-water conditions. That means potential property damage, erosion and flooding, plus safety concerns. Such wakes can even knock someone off a dock!

Local watercraft controls by county
Boat speed and no-wake restrictions Video

Swimming and beach safety

beach flag warning systemHigh-water conditions can cause stronger currents, especially around river outlets and piers. It’s best to swim at designated beaches, where you can keep an eye on the beach flag warning system and easily monitor swim conditions:

Red = Stop. Do not enter the water and do not swim.

Yellow = Caution. Watch for dangerous currents and high waves.

Green = Fair. Enter the water but stay aware of changing conditions.

Great Lakes beach safety tips

Boating in higher water

Higher waters can cause fast-flowing currents, deeper and colder water, unpredictable conditions and more debris floating under the water’s surface – especially on rivers. The law requires that all vessels, including kayaks and canoes, be equipped with a personal flotation device for each person on board.

High water levels can also affect boat launches. Check our DNR closures page to see which launches have been closed.

Wildlife and fisheries habitat

Many wildlife species are adaptable and can relocate when high water threatens their habitat; however, some ground nesting birds like eastern meadowlarks, wild turkeys, mallards and piping plovers can experience nest failures when flooding occurs, which can mean the loss of young birds.

Wakes – the flow of water caused by a boat or something else moving through the water – can intensify flooding. To help alleviate flooding, wake restrictions are in place to protect shoreline habitat for fish and animals.