01:02 Great Lakes Could Top Record Levels Due to the massive winter snowpack and the amount of rainfall over multiple cities, the Great Lakes could soon set record levels.

At a Glance Water levels on the Great Lakes are running high and could approach record territory this summer.

New York state is bracing for flooding along the shoreline of Lake Ontario.

Lakeshore flooding is already occurring in northwestern Ohio and southeastern Michigan.

Great Lakes tributary waters have been filled by numerous spring rain events in the central U.S.

Recent rainfall has already-high water levels surging in the Great Lakes, contributing to flooding along the lakeshores in parts of Ohio and Michigan, and New York is expected to follow suit in the days ahead.

Areas along the Lake Ontario shoreline are "at the precipice of a disaster," according to New York Gov. Andrew Cuomo, as forecasts for additional rain threaten to push water levels past flood level. The worst of the flooding from heavy rain and snowmelt is expected to occur in a matter of days, and officials are concerned that stronger winds late this week into the weekend could churn up potentially damaging waves.

New York state deployed more than 800,000 sandbags, hundreds of pumps and 920 feet of temporary dams in eight counties along Lake Ontario in preparation for potential flooding, according to the Associated Press. Members of the New York National Guard are on standby.

Rising waters resulted in extensive damage along the lakeshore in 2017. The flooding cost the Empire State $100 million in recovery funding, according to the AP.

(MORE: Northeast Is Rain-Fatigued, But It Might Catch a Break Soon)

There are also lakeshore flooding concerns north of the border in Ontario, Canada, where the Toronto Region Conservation Authority (TRCA) has issued a shoreline hazard warning until further notice. The Toronto Islands and other lakeside communities in Ontario felt effects similar to New York state in 2017, when high water levels on Lake Ontario and significant flooding devastated the area.

"Properties along the shoreline and the Toronto Islands, which experienced flooding during the 2017 event, could begin to experience flood impacts as the water level in Lake Ontario continues to rise ," the TRCA said.

Flooding is already occurring in northwestern Ohio and southeastern Michigan, as western Lake Erie is in "uncharted territory with near-record-high levels," according to the National Weather Service.

Port Clinton , Oak Harbor and Fairport Harbor were among the northwestern Ohio towns dealing with lakeshore flooding on Wednesday. The only way to get around Port Clinton was by boat or paddle board .

In southeastern Michigan, residents of Monroe County's Berlin Township became trapped in their homes by high water along the shore of Lake Erie on Wednesday. Firefighters used a boat to rescue those who were stranded. Pumps were used to clear roadways in nearby Frenchtown Township.

Last week, people used sandbags to hold back floodwaters in southeastern Michigan. Gov. Gretchen Whitmer earlier announced a state of emergency in Wayne County, which includes Detroit.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/ap19129454032438.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/ap19129454032438.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/ap19129454032438.jpg?v=ap&w=980&h=551 800w" > In this Wednesday, May 8, 2019, photo, Estral Beach Firefighters Courtney Millar, Eric Bruley and Chase Baldwin kayak down Lakeshore Dr. in the south end of Estral Beach in Berlin Township, Michigan, to see if anyone needs to be evacuated while also checking the floodwaters. Wind-driven water caused more flooding in southeastern Michigan along western Lake Erie following recent rainfall that contributed to high water levels in the Great Lakes. (Tom Hawley/The Monroe News via AP)

A six-month bulletin from the U.S. Army Corps of Engineers indicated water levels on lakes Superior and Erie may reach record or near-record highs this summer, due to a combination of a heavy winter snowpack melting across northern portions of the region and water rushing into the lakes from rivers swollen with spring rainfall.

"Preliminary estimates indicate that all of the Great Lakes received above-average precipitation in the month of April," the bulletin said. "Each lake exceeded their average April precipitation by at least 24%."

Lake Erie's April precipitation was the farthest above average of all the Great Lakes at 37%.

In addition, the water levels of all the lakes increased in April, ranging from 2 to 7 inches above their levels from one year ago. Lake Superior was just 3 inches shy of its April record high.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/ap19126686799387.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/ap19126686799387.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/ap19126686799387.jpg?v=ap&w=980&h=551 800w" > In this April 6, 2017, file photo, big waves crash against a breakwater light as strong winds create dangerous conditions on Lake Michigan, at Washington Park in Michigan City, Indiana. Federal officials predict surging water levels across the Great Lakes and record or near-record highs in lakes Superior and Erie over the next six months. A report Monday, May 6, 2019, from the U.S. Army Corps of Engineers said the lakes have been rising steadily for several years and are getting an extra boost as winter's melting snow mingles with recent heavy rainfall. It's a remarkable turnaround from early this decade, when lake levels were slumping and some hit record lows. (Robert Franklin/South Bend Tribune via AP, File)

Great Lakes levels have been trending upward at various rates since 2013, when lakes Huron and Michigan fell to their lowest levels and the other Great Lakes were significantly below average.

Water levels are known to fluctuate over time, sometimes running high or low for several years at a time. Over the 21st century, as temperatures warm and more water evaporates, the typical Great Lakes water level is projected to drop slightly, according to the 2018 U.S. National Climate Assessment . However, there is a wide range of uncertainty in that projection.

Climate change is also increasing the intensity of the most extreme rainfall events, which could, in turn, boost the levels of prolonged Great Lakes high-water events.

"These events are quite consistent with what scientists have been expecting with long-term climate change patterns," Drew Gronewold of the University of Michigan's School for Environment and Sustainability told the AP. "The challenge is that it's very hard to forecast when those extremes are going to occur and when the transition between them might occur."

The central U.S. has been the target of numerous heavy rain events this spring, which have filled Great Lakes tributary waters and churned up big waves that are eroding shorelines, Guy Meadows, director of the Great Lakes Research Center at Michigan Technological University, told the AP.

(MORE: Another Great Midwest Flood of 1993 This Summer?)

"We expect lake levels to fall again, but this episode of high water is going to take a couple of years to work its way through the system," said Meadows. "It's going to be a big hit."

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/ap19121680399336.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/ap19121680399336.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/ap19121680399336.jpg?v=ap&w=980&h=551 800w" > The roof and open hatch are the only visible signs of a vehicle submerged in floodwaters at the Monroe Blvd underpass at Interstate 94 in Taylor, Michigan, Wednesday, May 1, 2019. Rain across the Detroit area left scores of basements flooded and made some local streets impassable. Some vehicles had to be towed from the water. (Max Ortiz/Detroit News via AP)

Interestingly, when one side of a particular Great Lake is running high, the opposite side is typically much lower, as the NWS office in Cleveland pointed out in a tweet about Lake Erie . That's because the wind often pushes the water from one end of the elliptically shaped lake to the other.

No recent flooding has occurred along the eastern shores of Lake Erie because water levels there are much lower than along the western shores, where flooding has occurred in Ohio in Michigan.