Let’s talk water levels. Despite growing concern over low water levels in recent years, the Great Lakes are seeing record highs and coastal flooding in 2017. There has been talk among residents and the scientific community that low flows are a sign of climate change. So how do we contextualize the extreme spike in water levels causing flooding in southern Ontario, Quebec, and upstate New York? [photo credit: photographer Daniel Williams surveys the Toronto skyline from flooded Toronto islands.]
Spring 2017: reversing trends
As early as April, the International Joint Commission predicted that the Great Lakes water levels were expected to stay above the long term average.
On June 12, the U.S. Army Corps of Engineers sent a news release stating that not only did they expected Great Lakes water levels to be higher than average – they were to continue being higher through the fall. Keith Kompoltowicz attributed the prediction to above average precipitation on the Great Lakes, and very wet conditions in April and May. Kompoltowicz is chief of Watershed Hydrology at the U.S. Army Corps of Engineers, Detroit District.
The release went on to state that summer water levels for lakes Superior, Michigan-Huron, St. Clair, and Erie were forecasted to be at their highest levels since 1996-1998. After severe precipitation events in the spring, Lake Ontario has set a record high monthly mean water level in May. The Army Corps states that, “at 248.96 feet, May’s level was the highest monthly mean for any month in the 1918-2016 period of record.”
The Army Corps have only been measuring water levels within the last century, since 1918. Lake Ontario’s previous record was set in 1952, at a height of 248.56 feet.
Flooding woes and pointed fingers
You’ve probably heard it broadcasted throughout the spring on national radio, television, and news headlines. High water levels have wreaked havoc on a number of coastal communities in the Great Lakes basin, and along the St. Lawrence seaway. Residents of southern Ontario, Quebec, and upstate New York are coping with devastating flood damage to homes, businesses, and infrastructure, including “shoreline erosion, flooded roads, battered breakwalls, submerged docks and boat launches.” The ever-popular Toronto islands have sustained severe flooding as well. The Toronto Star reports that flooding has cancelled ferry services until July 31, distressed island-dwelling homeowners and businesses, and left the bustling islands bereft of thriving tourism. New York Governor Andrew Cuomo has bemoaned broader economic fallout for U.S. communities as well, lamenting “devastating” effects seasonal tourism in an article by CityNews.
Some residents and local officials, including Gov. Cuomo, feel the International Joint Commission bears the blame for exacerbating flood damage. The IJC is in charge of the board which decides how much water to release from the Moses-Saunders power dam in Cornwall, ON, which increases outflow of water from Lake Ontario to the St. Lawrence River. Gov. Cuomo is quoted in the CityNews article as stating that the IJC “pulled the trigger too late on releasing outflows.” Water had been held back in Lake Ontario in the spring, due to flood-level spring runoff in the Ottawa River. Massive precipitation compounded the problem.
The IJC has responded that no one could have predicted the record spring rainfall which raised water levels. Beginning on June 14, the International Lake Ontario-St. Lawrence River Board gave approval for the Moses-Saunders power dam to begin releasing outflows of 10,400 cubic metres per second – the highest outflow ever released on a sustained basis. The decision didn’t come lightly. The IJC must factor in the effects that higher outflows will have on already flooded communities downstream, as well as increased currents affecting cargo ship traffic. An article from CBC also warned recreational boaters to take caution in the increased current.
As of June 21, the IJC stated that the dam was still operating at 10,400 cubic metre per second outflows. It also reported that continued monitoring demonstrated no adverse effect to communities downstream, and that water levels in the Lake Ontario and St. Lawrence were beginning to decline.
Where does Superior stand?
Like the rest of the Great Lakes, Superior’s water levels are higher than normal. As of June 6th, U.S. Army Corps’ data showed that the Big Lake was sitting 7 inches higher than the June average. (Credit: U.S. Army Corps of Engineers chart published via Cleveland.com on June 6).
The Corps updated their data on June 23rd, showing that Superior increased to an 11 inch difference for the long-term June monthly average. It also shows that it was only 2 inches under the highest-ever monthly average on record, dated 1986.
Why do Superior’s water levels matter? Its increase is not as notable as the other lakes – the 11 inch June monthly average difference pales in comparison next to Michigan-Huron’s 15 inches, St. Clair and Erie’s 19 inches each, and Ontario’s 28 inches.
Very simply, it matters when we take into account the “bath-tub” effect of the basin. Reading left to right on this chart shows the relative elevation of the lakes. If one basin rises, it spills into the next. Topographically, Superior is at the highest elevation; which drains to lakes Michigan and Huron; which drains to St. Clair and Erie, and so on. As can be seen, the last stop is Lake Ontario. If water levels are elevated in the higher basins, such as Superior and Michigan-Huron, that spells drainage trouble for the already-taxed Lake Ontario.
The Corps prediction, as of June 23: “Lake Superior’s outflow through the St. Marys River is projected to be above average in June. Lake Michigan-Huron’s outflow into the St. Clair River, and Lake St. Clair’s outflow through the Detroit River are also predicted to be above average. Lake Erie’s outflow into the Niagara River is forecasted to be above average, and outflow of Lake Ontario into the St. Lawrence River is projected to be above average for the month of June as well.”
As with other Great Lakes regions, coastal communities on Lake Superior have seen, and continue to see, high levels of precipitation in spring and continuing into summer. For all the lakes, high precipitation was compounded by spring runoff from melting snow in surrounding areas.
The big picture
CBC columnist Don Pittis wrote an article at the beginning of June to help readers contextualize rising water levels in terms of cost – both economic and environmental. Pittis frames his June 1 piece starkly: “[As] U.S. president Donald Trump hints he will pull out of the Paris climate agreement, experts are warning that taxpayers must be prepared to eventually spend big in order to cope with changing climate in the Great Lakes Basin.”
[note: Pittis’ column was posted to CBC as of 5 a.m. EST on June 1. By 2:41 p.m. EST on the same day, CBC reported that Trump had officially announced U.S. withdrawal from the Paris climate agreement.]
Pittis begins his article by pointing out that fluctuating water levels can have positive impact on the Great Lakes ecosystems. He states that “the rise and fall of water levels recharge wetlands and scour shorelines.” Hydrology is a critical component of Great Lakes habitat.
Consulting with McMaster University engineering professor Gail Krantzberg, who has been studying the Great Lakes for 30 years, Pittis notes that most of the recent economic studies undertaken about water levels have focused on the impact of low levels – not high. Engineer David Fay, an advisor to the IJC, corroborates this.
“Certainly on the upper Great Lakes, the levels were low for a little over a decade,” says David Fay, a Canadian engineer who advises the IJC.
He says levels on Lake Huron hit an all-time low in 2013, forcing ships on the St. Lawrence Seaway to reduce loads and cutting the amount of water available for generating electricity. Ferry services were interrupted, marinas were left high and dry, and recreational property users faced with a long, mucky hike out for a splash in the lake.
The low water levels in the upper Lakes were blamed on climate effects: low precipitation and warm temperatures that led to poor ice cover and higher rates of evaporation.
The volatility of climate change can also contextualize why the Lakes are seeing a massive spike in water levels after years of consistently low measurements. While some fluctuation is to be expected, and can even be positive, increasingly extreme weather makes it difficult for organizations like the IJC to predict and manage water levels.
Using the bath tub analogy, Pittis provides a lengthy explanation of why this year’s factors were particularly difficult to control under the ‘Climate effects’ and ‘Pull the plug’ sections of his column.
Because water levels remained low for many years, land owners were increasingly tempted to develop properties closer to shorelines. Now that the levels are surging back, business owners and residents are seeing property damage from flooding. This makes Great Lakes coastal management – which Infosuperior reported on in the June 1st newsletter – a particularly hot topic for researchers, residents, and municipalities alike.
As Pittis points out, the fluctuations are becoming more extreme, and therefore more expensive. While the tally of flood damage continues to roll into the hundreds of millions, or billions, “the biggest expense will be rebuilding public infrastructure to cope with increasingly volatile conditions caused by climate change.”
He quotes University of Windsor water engineer Tirupati Bolisetti to explain why climate fluctuations mean big bucks for taxpayers.
Bolisetti’s own research shows that while the number of rainy days is declining, “any given rainfall is significantly higher than we used to have in the past.”
“When you have to design the stormwater or flood-control structures, what used to be 25-year storm events have become five-year storm events now,” he says. “What used to be 100-year storm events have become 25-year storm events.”
So what kind of spending will be required in the Great Lakes Basin?
“If I had to project the costs for the reconstruction and upgrading of the infrastructure for climate change preparedness, it will be easily a few hundreds of billions,” says Bolisetti.
InfoSuperior Tools – Lake, River, and Climate Data (includes several monitoring tools such as a Great Lakes Water Level Viewer and real-time river flow data from Environment and Climate Change Canada, NOAA, OPG and more.)