How Climate Change Could Impact Great Lakes Algal Blooms and Ice Cover

By Kevin Bunch, IJC

Ice cover on the Great Lakes in Feb. 19, 2014. Credit: Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response TEAM at NASA GSFC
Ice cover on the Great Lakes in Feb. 19, 2014. Credit: Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response TEAM at NASA GSFC

Climate change is expected to impact locations across the globe, including the Great Lakes. Experts say warmer temperatures, more severe spring storms and reduced ice cover will make it easier for harmful algal blooms to grow and remain in lake waters. What’s more, it seems that winter isn’t putting a brake on algal growth in Lake Erie – just changing the type of algae.

Globally, this year is on track to be the warmest on record. Last year, the Great Lakes experienced a warmer and drier winter than usual thanks to the El Niño effect from the Pacific Ocean. That warmth kept ice cover low on the Great Lakes, and thanks to a relatively dry spring the 2016 algal bloom on Lake Erie was much smaller than in recent years. But are these trends or simply outliers? It’s complicated.

Common sense would suggest that as the Great Lakes climate warms up, ice cover would be reduced. There are other factors too, according to Jia Wang, ice climatologist for the National Oceanic and Atmospheric Administration (NOAA) in Ann Arbor, Michigan. The major player is the jet stream encircling the globe in the northern latitudes. As the jet stream fluctuates, colder and warmer air moves around to follow it. In some years, like the winters of 2013-14 and 2014-15, the jet stream’s shape drags frigid arctic air from Alaska and Canada southeastward, leading to colder temperatures and thus greater ice cover on the Great Lakes.

Wang said data on ice cover for the Great Lakes only goes back to 1973, but there appears to be a cycle   showing increasingly reduced ice cover into the ‘90s before a rebound in the 2010s. Based on the data, the basin lost 26 percent of its maximum ice cover from 1973 through 2015, with Lake Superior losing the most – about 39 percent. Cold winters starting in 2013 and 2014 brought ice cover to levels seen in the late 1970s, though.

The amount of ice cover on the Great Lakes fluctuates each year, but there is a downward trend over the past 40 years, possibly due to global climate change. Source: Draft State of the Great Lakes Report as presented at the Great Lakes Public Forum
The amount of ice cover on the Great Lakes fluctuates each year, but there is a downward trend over the past 40 years, possibly due to global climate change. Source: Draft State of the Great Lakes Report as presented at the Great Lakes Public Forum

Environment and Climate Change Canada (ECCC) Research Manager Ram Yerubandi says lake water temperatures have been increasing, according to decades of available data. Less ice cover in the winter means the lakes could see increased evaporation, which in turn would reduce water levels. Climate change models for the Great Lakes are split on whether the region could see decreased water levels. Models show increased precipitation, particularly through more spring storms which could mean more nutrient runoff for harmful algal blooms to feast upon in the summer.

Warmer Temperatures and Less Ice Could Strengthen Algal Blooms

Less ice cover could bring a host of other changes to the Great Lakes ecosystem. Arthur Zastepa, research scientist with ECCC, said there are algae called diatoms that bloom during the winter in Lake Erie. These brown algae form their blooms under the ice and in cracks, attaching themselves to it so they can grow.

“Life is thriving out there in the winter time,” Zastepa said. “However, we don’t quite understand the link between wintertime production and the effect it has on hypoxia (low-oxygen conditions) and algal blooms in the summertime and the mechanisms responsible.”

Zastepa said scientists are still trying to understand what happens to these blooms when the spring hits, though recent investigations suggest that they settle into the sediment and begin to break down when temperatures rise, contributing to hypoxia.

An upturned piece of ice with brown algae growing on it was spotted during a 2008 Bering Sea expedition. Credit: C. Ladd
An upturned piece of ice with brown algae growing on it was spotted during a 2008 Bering Sea expedition. Credit: C. Ladd

Brown algae isn’t as bad as the blue-green variety known as cyanobacteria, which can produce toxins associated with harmful algal blooms. After nutrient-rich runoff enters the water system in the spring, blue-green algae can explode into blooms in July that last into October.

This year, while the larger bloom in Lake Erie had broken up by October, patches of it were still growing well into the latter part of that month. Zastepa said a warmer fall could be keeping those warm water-loving cyanobacteria going. Scientists are looking for these blooms earlier and later in their “growing season.”

A dry summer also could play a role. If major rain events drive a lot of nutrients into Lake Erie in the spring and are then followed by a drought keeping the water column stable and stagnant, those potentially toxic cyanobacteria can thrive. While forecasts for 2017 only go through February, the US Climate Prediction Center expects wetter weather in the Great Lakes region during that period.

A satellite image of the 2011 harmful algal bloom on Lake Erie, which was the second worst bloom on record. Credit: MERIS/ESA, processed by NOAA/NOS/NCCOS
A satellite image of the 2011 harmful algal bloom on Lake Erie, which was the second worst bloom on record. Credit: MERIS/ESA, processed by NOAA/NOS/NCCOS

Heavier Spring Rains Could Provide More Food for Algae

There are additional climate impacts, and scientists are still trying to find out how they are connected to each other. Timothy Davis, a NOAA research scientist, said more spring rainfall in the region due to climate change could mean more nutrients entering the lakes and increase the overall flow from tributaries into the lakes. More rainfall also increases the likelihood of sediment washing into the lakes, reducing the amount of light getting into the water – which in turn could impact how summer blooms form and how toxic they become.

There are studies suggesting the most dominant blooming form (and potentially toxic) cyanobacteria microcystis produces more toxins at higher water temperatures and in a more nutrient-rich environment. Those same higher water temperatures could negatively impact invasive mussel species in the Great Lakes, whose filter-feeding methods further reduce competition for microcystis. There also haven’t been any studies completed on how climate change would impact the ability of the United States and Canada to achieve 40 percent nutrient loading reductions into Lake Erie, Davis said. Those unknowns make it hard for models to predict what could happen in the future in terms of bloom size and intensity, he said.

Climate change occurs on a decadal time scale and experiments take place on significantly shorter scales. Davis says climate models have a hard time making regional predictions on what will happen in the future with the Great Lakes, though trends suggest it will be hotter and generally drier, punctuated with severe storms.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

What are Chemicals of Mutual Concern?

By Kevin Bunch, IJC

When the United States and Canada signed the Great Lakes Water Quality Agreement of 2012, the two countries agreed to draw up a list of chemicals of mutual concern (CMCs): human-made substances that pose a threat to human health and the environment that the governments want to target for binational action. The governments have agreed to an initial list of CMCs and are drafting strategies on how to reduce their presence in the Great Lakes region and deal with existing contamination.

In May 2016, the first eight CMCs were announced by the countries. The list includes mercury, flame retardants like hexabromocyclododecane (HBCDs) and polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), perfluorinated compounds (PFOAs, PCOS and PFCAs), and short-chain chlorinated paraffins (SCCPs). The names are as messy as their impacts are long-lasting and far-reaching, as they can build up in tissues and cause health problems for animals and people alike.

Hamilton Harbour, located on the western end of Lake Ontario, is just one site in the Great Lakes dealing with the chemicals of mutual concern named by the United States and Canada. Credit: Environment and Climate Change Canada
Hamilton Harbour, located on the western end of Lake Ontario, is just one site in the Great Lakes dealing with the chemicals of mutual concern named by the United States and Canada. Credit: Environment and Climate Change Canada

The two parties released a series of reports on each chemical. The researchers found that even though most PCBs were banned in the 1970s and usage for special circumstances such as in scientific instruments and transformers has fallen for decades, levels still routinely exceed guidelines and drive fish consumption advisories in all the Great Lakes. This is because the chemicals are long-lasting, are wrapped up in the food web and bioaccumulate in those species further up the chain, such as lake trout or gulls.

According to a series of documents from the CMC Identification Team – comprised of experts from both countries and appointed by the governments – mercury is also on a downward trend in the Great Lakes, but is still at threatening levels to the environment and human health. Moreover, a 2015 IJC report on air deposition of mercury in the Great Lakes found that mercury levels in some species of fish are increasing. PBDE concentrations in fish like walleye and lake trout, along with sediment and gull eggs, exceeded safe guidelines and show no clear evidence of declining at this point; the same is true for the perfluorinated compounds, according to the Identification Team.

A gull incubates its eggs near Saginaw Bay, Michigan. Legacy contaminants such as PCBs have been found in the eggs even recently. Credit: US Fish and Wildlife Service
A gull incubates its eggs near Saginaw Bay, Michigan. Legacy contaminants such as PCBs have been found in the eggs even recently. Credit: US Fish and Wildlife Service

But what do these chemicals do to living creatures? HBCDs are toxic to aquatic species and can cause respiratory, gastrointestinal and skin irritation in humans. PBDEs can impact thyroid and metabolic systems. Mercury can cause a slew of neurological problems ranging from speech and motor skills to cognitive development issues in children. PCBs can cause skin irritation in adults and development issues in children, as well as cancer in animals. The effects of perfluorinated compounds isn’t well known, but studies suggest it could increase cancer rates.

Compiling a list is just the first step, and the governments are now drafting strategies to deal with CMCs. According to the Great Lakes Water Quality Agreement) and its annex on CMCs, plans being considered include research, monitoring, surveillance, and pollution prevention and control actions. The IJC also is working on a series of recommendations for a strategy on PBDEs, with a final report due this fall.

In Canada, all eight CMCs are already covered by the Canadian Environmental Protection Act of 1999’s list of toxic substances, as well as under its Chemicals Management Plan. CMCs already are subject to federal risk management efforts by the government, which include environmental guidelines at the federal level. Environment and Climate Change Canada (ECCC) also is supporting the creation of provincial guidelines to help deal with CMCs. ECCC handles monitoring and surveillance for water quality in the Great Lakes watershed.

In the United States, the Environmental Protection Agency handles the monitoring and surveillance of water quality – including the effects of CMCs — in the watershed, and funds research on the trends, presence and effects of CMCs through the Great Lakes Restoration Initiative. The chemicals are regulated in the US depending on how they’re used and released, and where they are made. Those regulations exist on the federal, state and local level, though for the federal government those efforts stem from the Toxic Substances Control Act, updated most recently on June 22, 2016. In the PROP, the US government notes that it will be more closely aligning its federal actions with those on state and local levels to improve its CMC-specific efforts around the Great Lakes.

The two countries have just started – naming the first CMCs was only one step in the process – and they are drafting a second set of CMCs to add to the binational list and coming up with strategies to address the initial eight. An initial nomination period that allowed for the public to forward chemicals for consideration ended on Aug. 29, 2016. There is no timeline on when the second round of chemicals will be announced.

Industrial areas, like this one on the St. Clair River near Sarnia, Ontario, have historically been one source for the pollutants found in the CMC list in the Great Lakes basin. Credit: Environment and Climate Change Canada
Industrial areas, like this one on the St. Clair River near Sarnia, Ontario, have historically been one source for the pollutants found in the CMC list in the Great Lakes basin. Credit: Environment and Climate Change Canada

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Safe Drinking Water Requires Several Steps

By Kevin Bunch, IJC

Credit: US EPA
Credit: US EPA

One of the Great Lakes Water Quality Agreement’s objectives is to make sure that the lakes are a source of safe, high-quality drinking water. The safer that source water is, the less money and effort needed by local utilities for treatment. To inform people who consume Great Lakes water, Canada and the US have rules on the books requiring water utilities to report on the quality of the drinking water they provide.

Municipal water systems in Canada and the US are required to make sure water is safe after its been treated, but protecting water at the source is just as important. Some potential contaminants can’t be easily removed at treatment plants, and water treatment is generally an expensive procedure. As a result of active efforts to protect water sources and treat incoming water, however, public utilities in both countries provide safe drinking water except in cases of rare, well-publicized disasters, such as recent lead in Flint, Michigan’s drinking water, or Walkerton, Ontario’s E. coli outbreak in 2000. Part of the International Joint Commission’s task under the Great Lakes Water Quality Agreement is to assess whether those sources of water are being protected. The Commission has found “that drinking water in the basin was very likely to be safe given present treatment measures for presently identified biological, chemical and physical contaminants.”

Under the US Environmental Protection Agency’s Safe Drinking Water Act guidelines, all community water systems across the United States must prepare an annual “consumer confidence report.” If the utility serves more than 10,000 people, the report must be mailed out. Otherwise it can be mailed, posted publicly or made available in a local newspaper. For example, see 2015 reports here on the Eastpointe, Michigan, water system and here on the Rochester, New York, water system.

These reports explain where a system’s drinking water comes from, testing done for contaminants like nitrates, barium, chlorine, copper and lead, and testing results. Not all contaminants are necessarily harmful – some, like sulfates or iron, only impact the taste or appearance of water. But some, like lead, can have major impacts on human health. The EPA sets minimum safe standards for drinking water, though states can adopt stricter standards.

“The information contained in (these) reports can raise consumers’ awareness of where their water comes from, help them understand the process by which safe drinking water is delivered to their homes, and educate them about the importance of preventative measures, such as source water protection, that ensure a safe drinking water supply,” the EPA wrote in the summary of its final approved rule in 1998.

Under the Ontario Safe Drinking Water Act, the Ontario Ministry of Environment requires annual reports – such as these from Toronto – from every drinking water plant that serves more than 100 people. These reports are not necessarily sent to every resident, but are typically found on the city website of the municipality providing the water. Ontario also requires that owners of community drinking water systems test water in the plumbing inside a home or building and in distribution pipes throughout an area to make sure there is no contamination between the water plant and the water coming out of your faucet.

The R.C. Harris Water Treatment Plant is one of several that serve the Toronto area. Credit: r h via Flickr
The R.C. Harris Water Treatment Plant is one of several that serve the Toronto area. Credit: r h via Flickr

Every year, Ontario also releases a Minister’s Annual Report on Drinking Water, which includes a section on provincial efforts to protect drinking water. Topics include climate change, First Nations-specific issues, source water protection and other concerns specific to the Great Lakes. The province also regularly releases the Chief Drinking Water Inspector Annual Report, which focuses on source water protection, the quality of drinking water across the province, and water test results at the point of use (including for substances like lead).

Water and its protection and safety is an issue that unites people in both countries, particularly around a watershed as massive as the Great Lakes. The safeguards in place to protect source waters – and public reporting of testing results – provide important assurances that we can continue to enjoy a cool drink of water.

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

One Water: A New Way to Think about Water Systems

By Kevin Bunch, IJC

Rain barrels are a way to capture precipitation and keep it from becoming runoff. Credit: Winooski Natural Resources Conservation District
Rain barrels are a way to capture precipitation and keep it from becoming runoff. Credit: Winooski Natural Resources Conservation District

Cities and other communities tend to disrupt the natural water cycle of an area. In natural environments, water falls as precipitation, seeps into the soil and eventually enters the groundwater system, connecting to surface-level waterways. When an area has been developed, more water runs off of hard surfaces like pavement and roofs into storm sewer systems before being dumped into a river or lake, along with any garbage and contaminants like oil or grease carried along by the water.

A new approach known as One Water is aiming at a more holistic system between standard city development and nature for communities to manage their water, from water withdrawal and use to sewage disposal and stormwater management.

“We have to look at the entire system and the entire way in which we use and move water as one integrated cycle and integrated system,” said John Jackson, projector coordinator for the Greater Lakes project with the Great Lakes Commission. “We’re not doing (water reuse and recycling) so much here in the Great Lakes because we have this myth of an endless supply of water because of the lakes, but it’s still very precious.”

More intense storms due to climate change are expected to exacerbate sewage overflows and stormwater runoff contamination to water systems. In addition, over-pumping underground aquifers pulls water from surface water areas that rely on those aquifers to replenish and recharge. This can destroy habitat for fish, wildlife and plants.

A “Greater Lakes” report by the Great Lakes Commission found that in six Michigan and Ontario communities, outdoor water use has the biggest impact on groundwater recharge rates, since changes in water use restrictions and plumbing codes have already helped conserve water.

Storm drains can lead to major erosion issues along waterways, and can back up if there’s too much water from major storms. Meanwhile, small wastewater lines and too much use can lead to capacity problems at treatment plants.  Jackson said it is “wasteful” to do something like use water once to flush a toilet and then discard it from the system entirely.

By managing the system as a whole through water conservation practices (like rain barrels) and replacing infrastructure like combined sewers, cities could be saving money and healing the water cycle. There are other benefits, too – fewer greenhouse gas emissions and less energy used from distributing water for long distances, according to a “Greater Lakes” fact sheet.

A rain garden can help soak up rain and hold onto the water until it seeps into the ground, while also helping plants. Credit: MA Watershed Coalition
A rain garden can help soak up rain and hold onto the water until it seeps into the ground, while also helping plants. Credit: MA Watershed Coalition

For example, one way to make these systems more effective is to reduce the amount of water running off into storm drains, Jackson said. Municipalities can make sure there are drainage ditches alongside applicable roads that will hold onto the water until it can seep into the ground.

Rain gardens can accomplish the same task on residential scales, while using rain barrels and cisterns to capture water from a home’s roof for other uses reduces runoff and the need to use more water from the tap.

Jackson said the barrels are typically used for gardening as an alternative to using a hose, while a cistern can provide water for toilets or washing machines. In either case, such practices reduce the amount of water going into expensive wastewater treatment systems. In some communities in places like Australia, Singapore and California – where water is becoming a scarce resource – water managers have started recycling wastewater to reuse elsewhere in the home, including as drinking water. Jackson notes this already happens for people who live downstream of another community and throughout the Great Lakes – where treated wastewater is put back into the water supply and used again – but the idea makes it a hard public sell.

Retrofitting existing buildings and sewer systems isn’t cheap, though. Jackson said communities replacing aging infrastructure should consider water-saving approaches and new development should automatically use these approaches – communities could even adjust building codes to make them mandatory for new construction.

The Great Lakes Commission’s Greater Lakes project has released a number of tools and informational packets, most notably the Green Infrastructure Optimization Tool, which can calculate the impact of different types of development, soil and rainfall on an area. While these are geared toward governments, Jackson said residents interested in green infrastructure should consider bringing it up to local leaders during planning or infrastructure discussions. In a matter of years, green infrastructure has become more of a mainstream concept, with more civil engineers and officials interested in considering it, and more community residents asking about it.

Permeable pavement, such as porous asphalt on the right side in this photo, allows water to seep into the soil beneath while filtering out pollution. Credit: EPA
Permeable pavement, such as porous asphalt on the right side in this photo, allows water to seep into the soil beneath while filtering out pollution. Credit: EPA

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

 

Ontario’s Invasive Species Act Targets Prevention

By Kevin Bunch, IJC

European water chestnut is an invasive species that Ontario hopes to combat with the help of a new invasive species law. Credit: Mike Naylor, Maryland Department of Natural Resources
European water chestnut is an invasive species that Ontario hopes to combat with the help of a new invasive species law. Credit: Mike Naylor, Maryland Department of Natural Resources

Ontario has the largest number of invasive species in Canada, with more than 180 aquatic invasive species, around 500 non-native plants, 39 known forest insects and 10 tree diseases. Officials now have a new tool to try and keep those numbers from ticking upwards.

On Nov. 3, a new Ontario’s Invasive Species Act goes into effect, giving officials in the province a stronger mandate to prevent new species from arriving and to control – and where possible, eradicate – those that are already here.

Jeff Brinsmead, senior biologist for the Ontario Ministry of Natural Resources and Forestry, said the act’s focus and value is in being “proactive” and preventing new invasives from getting introduced to the province. Brinsmead said the province has previously relied on several different “legislative mechanisms” to deal with invasive species, such as the Ontario Fishery Regulations and Fish and Wildlife Conservation Act.

The new law brings comprehensive invasive species legislation under one act, according to Jeremy Downe, senior policy adviser with the Ontario Ministry of Natural Resources and Forestry. The act gives officials broader flexibility to regulate pathways of invasion such as firewood, recreational boating, purchase and trade, and guard against species coming from one part of the large and ecologically diverse province to another.

The legislation doesn’t specify a list of invasive species. Instead, invasive species will be classified in regulation as either “prohibited” or “restricted” based on the outcomes of science-based risk assessments. Those risk assessments will be used as the baseline for invasive management and enforcement.

For example, Downe said the province could require recreational boaters to clean or drain livewells before leaving a lake so aquatic species can’t hitch a ride to another lake. Or officials could prohibit importing or selling certain horticultural plants that are considered invasive. They also could survey for invasive species and issue orders to keep people from doing things that could spread those plants and animals. As of Aug. 17, 2016, no policies or regulations have been finalized to roll out with the act.

A stand of invasive phragmites plants measuring taller than five meters (more than 16 feet). Credit: Janice Gilbert, Ontario Ministry of Natural Resources and Forestry
A stand of invasive phragmites plants measuring taller than five meters (more than 16 feet). Credit: Janice Gilbert, Ontario Ministry of Natural Resources and Forestry

The act also closes existing gaps left by previous laws and regulations. For example, the ministry has had limited powers to address invasive species on private land, but once the law goes into effect officials will have the authority to access and control invasive species on private land when required, or otherwise compel the property owners to address the invasive species if necessary.

The financial penalties are significant for breaking the new law, which Downe said was intentional due to the cost of dealing with invasive species. The province estimates that it spends CDN$3.5-4 million a year on invasive species control, research, awareness and education programs. These fines can go as high as $250,000 for an individual or $1 million for corporations. There also are multipliers for the number of an invasive species found and actions by individuals and businesses, such as selling or releasing harmful exotic plants and fish.

The act has been largely well-received, Downe said, though there has been “angst” in some quarters about the provisions to enter private land, particularly among the agricultural community.

Downe said the ministry intends to work with cooperatively with private land owners and Indigenous communities to address the impact of invasive species on their lands and activities.

Invasive round gobies have been found in Ontario waters such as Lake Simcoe for years. Credit: Center for Great Lakes and Aquatic Sciences Archive, University of Michigan
Invasive round gobies have been found in Ontario waters such as Lake Simcoe for years. Credit: Center for Great Lakes and Aquatic Sciences Archive, University of Michigan

“Generally it’s easier (to get support) with invasive species because everyone recognizes they’re bad and an issue, so when the issue came up it was widely recognized that more needed to be done,” Downe said. “The intent is not to (have) a huge impact on individuals; the initial focus will be on education, prevention and awareness.”

Some of the lessons learned from creating Ontario’s Invasive Species Act could be copied by other provinces, Downe said. If Ontario’s law proves successful at managing invasive species, it could end up being the vanguard to similar laws across the country.

Binational Groundwater Report Calls for Better Monitoring of Contaminants

By Kevin Bunch, IJC

A scientist takes a groundwater test sample. Credit: US Geological Survey
A scientist takes a groundwater test sample. Credit: US Geological Survey

Groundwater sources throughout the Great Lakes basin need to be better monitored and mapped. The work is needed to determine how quickly the sources recharge and the potential impact that contaminants in groundwater could have on water quality in the basin.

That’s according to a report recently released by the Canadian and US governments under the Great Lakes Water Quality Agreement.

Contaminants can work their way down the water table and impact groundwater and the quality of surface waters. The recent groundwater report indicates that this can impact fish populations, and ultimately the fish further up the food chain that we eat. Drinking water from groundwater and surface water sources can be impacted too, and excess nutrients in groundwater — from sources like septic systems, manure, fertilizer, leaking wastewater pipes and concentrated animal feeding operations — may contribute to algal blooms in lakes.

Because it can take anywhere from a few days to decades for groundwater to reach the surface, depending on the local geology and soil makeup, water quality managers may have to deal with these contaminants for years to come, long after their initial sources may have been cleaned up.

Recommendations

The groundwater report makes several recommendations on the science front. The authors suggest tracking groundwater as it moves into streams and the Great Lakes, and compiling locations of known and suspected sources of groundwater contaminants.

The report also recommends improving groundwater quality monitoring and surveillance to help fill information gaps. For instance, scientists want to know more about the interaction between groundwater and surface water on local-scales when it reaches the “transition zone” between the two.

Different kinds of bedrock in aquifers can cause differences in how quickly groundwater recharges. Credit: Granneman et al. 2000, USGS
Different kinds of bedrock in aquifers can cause differences in how quickly groundwater recharges. Credit: Granneman et al. 2000, USGS

What’s New

It wasn’t until the 2012 amendment to the Great Lakes Water Quality Agreement that Canada and the United States committed to coordinating groundwater science and management actions. Under the amendment, an “Annex 8 subcommittee” of experts from both countries was formed to identify groundwater impacts on the chemical, physical and biological integrity of the lakes, and analyze other issues. While the topic of groundwater has been a part of the agreement since 1978, progress reports weren’t required until 1987.

The vast majority of groundwater connects to surface streams, creeks and other waterways in the Great Lakes basin. According to a 2010 report from the IJC’s Great Lakes Science Advisory Board, 8.2 million people in the Great Lakes basin rely on groundwater to drink, including 82 percent of the rural population; it also provides 43 percent of agricultural water (and this proportion is increasing) and 14 percent of industrial water in the basin.

The Great Lakes, as seen from space by a NASA satellite. Credit: SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE
The Great Lakes, as seen from space by a NASA satellite. Credit: SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Where are Water Levels Heading on the Great Lakes?

By Kevin Bunch, IJC

lake michigan beach water levels great lakes noaa
A Lake Michigan beach located near Frankfort, Michigan, in September 2015. Credit: NOAA

Forecasting agencies in the United States and Canada expect Great Lakes water levels to remain near or above their long-term average for the next six months.

Water levels are measured on the International Great Lakes Datum, defined as the height above sea level at Rimouski Quebec on the St. Lawrence River estuary. According to the coordinated, binational forecast at the beginning of July, Lake Superior is expected to remain about 6 inches, or 15.4 centimeters, above its long-term average for this time of year through the summer, before falling closer to average levels in the fall. While this forecast is based on normal weather conditions in coming months, lake levels could be higher or lower depending on whether we have a wetter or drier than normal summer and fall. Long-term averages are based on data going back to 1918.

Lake Michigan-Huron, which have a common level due to their connection at the Straits of Mackinac, is expected to be 10-12 inches (30.8 cm) above average in the summer before falling closer to average in the fall. Lake Erie also is expected to be within 1 foot above average in the summer before ending closer to 8 inches, or 20.32 cm, above average in the fall. Lake Ontario’s July level is 1 inch (2.54 cm) below average for this time of year and is expected to remain close to average in the fall.

Jacob Bruxer, Environment and Climate Change Canada senior water resources engineer, said Lake Ontario’s comparatively lower water levels are due to the warm, dry weather conditions around the lake that started around March. Bruxer is also a member of the IJC’s International Lake Superior Board of Control and the Great Lakes-St. Lawrence River Adaptive Management Committee.

“Those conditions would be bad if we started at average levels, but we’re right around average,” Bruxer said. “We’re not seeing any significant concerns to shipping or recreational boaters.”

The higher water levels on Superior, Michigan-Huron and Erie mean some boat launches could be underwater and beaches are smaller than they would be with lower levels. On the flip side, boaters should have plenty of depth to get their boats into their docks, and anglers may find more coastal areas to fish than they would otherwise. Bruxer added that high levels can lead to greater erosion along bluffs and shorelines due to waves and storms.

Drew Gronewold, a hydrologist at the Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan, explained that the Great Lakes typically follow a seasonal cycle where water levels rise in the spring from runoff and peak in early summer. The lakes then fall in the autumn and winter months as evaporation — caused by temperature differences between the warm water and cool air — picks up, reaching their lowest point around January and February.

As of mid-July, Gronewold said there’s no indication that the autumn dip will be stronger than usual in the lakes, or that water levels will increase – something that occurred in the autumn and winters of 2013 and 2014 on Lake Michigan-Huron and Lake Superior. Bruxer said the lakes are expected to remain either near or slightly above seasonal averages for the foreseeable future.

Coordinated six-month forecasts of Great Lakes water levels are published online each month by the US Army Corps of Engineers and Environment and Climate Change Canada (via the Canadian Hydrographic Service). The US National Oceanic and Atmospheric Administration (NOAA) also provides these forecasts on its water level online viewer each month. Forecasted water levels are determined using binational data and several different models that account for possible variations in evaporation, precipitation and runoff on the lakes over the coming months.

While forecasts are typically only for a six-month period, the Army Corps of Engineers has recently developed a 12-month probability outlook.

Lauren Fry, civil engineer with the Corps, said the model provides potential outcomes given climatic scenarios, developed based on current conditions and similar existing historical weather data. For example, with the strong El Niño cycling over the past winter, Fry said the agency used data from  similarly strong 1982 and 1997 El Niño events to determine a range of potential lake level impacts from October 2015 until September 2016. The most recent one-year outlook from April suggests higher-than-average water levels will most likely continue until April 2017.

water levels measured feet meters great lakes michigan huron graph
Water levels are measured in feet or meters above sea level, with data compiled by US and Canadian organizations. The green line represents forecasted water levels, while the red line indicates recorded points for Lakes Michigan and Huron as of June 30. Credit: US Army Corps of Engineers

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.