Video of July 2020 Tri-Board Webinar on Great Lakes Water Levels and Answers to Additional Questions

Date

A public Great Lakes water levels webinar hosted by the International Joint Commission's Lake Superior Board of Control, Lake Ontario-St. Lawrence River Board and Niagara Board of Control was held July 17. This webinar provided an overview of why the Great Lakes were at their current levels and how IJC boards play a role in balancing the interests of all impacted by water levels in the Great Lakes.

After a presentation, members from the three boards and IJC staff answered a number of questions.

Due to time constraints, those present weren't able to answer every question posed by participants. Below, find a recording of the webinar and a table including answers to more than 80 additional questions from participants that we were not able to address during the webinar.

We hope this additional information helps clarify and inform those who participated and others who have questions and concerns about high water levels.

Question Asked

Answer Given

True resilience is not shoreline hardening.

There are many different methods for increasing shoreline resilience, and shoreline hardening is one option, but there are also a number of "softer" resiliency measures that can be used such as wetland rehabilitation. It really depends on the location and characteristics of the stretch of shoreline being considered for resilient measures. A coastal engineering professional should be consulted to determine what resiliency measures would be best suited for a specific stretch of shoreline.
 

https://www.glc.org/wp-content/uploads/GLC-Board-GLCRS-Outreach-Fact-Sheet-21Aug17.pdf: How does this fit in with the studies that were just referenced (the latest one was 2012)?

The previous IJC studies focussed on the development of improved regulation plans and an improved understanding of the factors that would impact those plans. The coastal resiliency study referenced in this question would not touch on regulation, but would instead focus on providing information to manage the shorelines themselves in a more resilient way. There may be some synergy between the studies in that some of the information generated from the resiliency study, such as an improved understanding in future wave climate or water levels, may help inform future regulation plan development. 
 

The ILOSLRB has shared that it will reduce outflows as needed to maintain Lake St. Lawrence above 73.0m. Would this be considered a deviation from Plan 2014? If yes, what criteria in Plan 2014 would allow deviation under the expected conditions when this would happen? If no, why not?
 

Yes, it would be a deviation under the IJC approved Board strategy to gradually offset the past year's deviations. The IJC's deviations directive (https://www.ijc.org/en/loslrb/who/directives/deviations) states the Board must develop an exit strategy when ending a period of major deviations. This strategy must include a way to offset the water removed or added from the lake under the deviations compared with what water levels would have been under adherence to Plan 2014. The strategy to maintain Lake St. Lawrence at 73.0 m or above is part of the Board's strategy to offset the past years' flow increases and was approved by the IJC.

What is the correlation in relative levels between Lake Michigan and downstream lakes? (2 inches reduction in Ontario were mentioned in the presentation.)

For Lake Ontario, the increase in outflow required to lower its level by 1 cm/inch over one week will cause roughly a 10x increase in levels in the lower St. Lawrence River, because the huge volume of water on Lake Ontario must pass through the much narrower St. Lawrence River. There are no flow control structures on the St. Clair, Detroit or Niagara Rivers, and water in Lake Michigan-Huron will flow into Lake Ontario or evaporate. As the water gradually flows downstream, evaporation and local precipitation will affect the volume of water reaching Lake Ontario. The hydraulic/hydrologic conditions of the lakes between Michigan-Huron and Ontario have a strong influence on the eventual impact to Ontario water levels.
 

Looking at aerial photograph evidence, is it time to admit that you have no idea of the actual conveyance on the St Clair River and therefore you cannot calculate NBS.
 

Aerial photos showing large amounts of sediment moving through the system do not necessarily mean conveyance is changing in the river as much of that sediment is flushed all the way through the river to its outlet. The US Army Corps of Engineers runs a comprehensive program of monitoring for conveyance change in the St. Clair and Detroit Rivers. Over the last 15 years repeat bathymetric data has been collected and analyzed for changes in the channel bottom. Flows have also been monitored closely for any potential unexpected changes. No significant changes have been identified in the channel conveyance to date. An updated analysis is currently underway and should be ready later next year.
 

When I referred to higher than historical average, I referred to pre-2012. I question what 2012 is doing to the balancing. Obviously not allowing to get to previous flows from early 1900s to 2008. Who can explain this to me to my satisfaction?

Despite record-levels in recent years, the average levels of Lake Superior and Lake Michigan-Huron have not changed significantly owing to the extensive period of record available (1918-present). Currently, the levels of both lakes Superior and Michigan-Huron remain well above their averages, so it should not be expected that the Lake Superior outflow would necessarily be below average. Nonetheless, owing to dryer conditions around Lake Superior over the past several months, Lake Superior's level is - relatively speaking - lower than Michigan-Huron's at this time. As a result, Plan 2012 is balancing the lakes Superior and Michigan-Huron levels by reducing the Lake Superior outflow below the natural outflow (or pre-project) that would occur at these Lake Superior levels, thereby reducing the level of Lake Michigan-Huron to closer to average.
 

Can you explain the gap in levels between Lake Superior and Lakes Michigan/Huron?

Difference in water levels on Lake Superior and Lake Michigan-Huron can be attributed to the geography of the lakes. Lake Michigan-Huron are located downstream of Superior and at a lower elevation. The difference in surface water levels of Superior and Michigan-Huron are, on average, approximately 7 meters (23 ft). Also, Lake Superior, being the most upstream lake in the Great Lakes system, only receives water from its own drainage basin - in contrast, Lake Michigan-Huron receives water from its own basin, as well as what is coming in from Lake Superior through the St. Marys River. Additionally, Lake Superior is smaller in surface area than Lake Michigan-Huron, and also has a relatively smaller drainage basin. As a result, Lake Superior inflows are less variable, and its water levels have historically shown less variation than Michigan-Huron for these reasons.
 

I'm hearing you say the lake levels can't be controlled significantly yet, then you outline what is done to control them. I know that in the Niagara River if you don't get to your dock before the time the power companies begin to draw you can't get in. The river drops approximately 1foot. Considering that as well as high water levels in the mid 90's how can you say these dams aren't significantly affecting our lake levels?

On the Niagara River, there are some local water level fluctuations due to the International Niagara Control Works (INCW) that are limited to the area of the Niagara River just upstream of Niagara Falls around the northern end of Grand Island. The INCW was constructed to divert water from an area of the Niagara River called the Chippawa Grass Island Pool, near the top of Niagara Falls for hydro power production, while helping spread water across the full rim of Niagara Falls so that it is attractive for tourism. The Niagara River drops several meters between Lake Erie and the top of Niagara Falls. For example, in June the average level of the pool at the INCW was 3.88 m (12.7 feet) below the level of Lake Erie. The INCW has some small impact on the water levels close to it, but it is too low (in elevation) and doesn't fully cross the Niagara River, and thus can't physically affect the water level in Lake Erie. 

The amount of water leaving Lake Erie into the Niagara River is based on the natural level of Lake Erie, and the local wind conditions that may blow additional water down the Niagara River. The higher Lake Erie is, the higher the flow down river. The dam in the St. Lawrence River has an impact on Lake Ontario's level. Lake Erie is much higher in elevation than Lake Ontario; water must flow over Niagara Falls to drop into Lake Ontario. As well the Niagara River drops over Niagara Falls which is 50 m (150 feet), so the level of Lake Ontario has no effect on the flow out of Lake Erie. This is a massive drop, and the lower water in Ontario doesn't affect water levels anywhere above Niagara Falls at all.

Understandably, the lake levels have historically been affected by rainfall in the Midwest. The high levels do align with those wet weather years. Can more water be diverted into rivers such as Allegheny, Missouri, Ohio?

There are no watercourses presently connecting the Great Lakes to the rivers you mention. Diversions of Great Lakes Water to other watersheds must be approved by both Countries and would require review of Global Affairs Canada and the US Department of State. Provided that such an action were even approved by the governments, the capacity of these river systems would be inadequate to remove enough water from the Lakes to make any meaningful reductions in water levels.

So, in other words, you don't and can't control any of the lake levels significantly. That's hard to believe since there were nearly as high water levels in the mid-late 90's and Lake Ontario didn't have as large an impact on property owners. How do you explain that?

The high water levels in 1993 did cause impacts to property owners. We highlighted a news clip from February 1993 on Lake Ontario in the presentation illustrating flooding of a shoreline property. It is true that water levels did not get as high in 1993 as in 2017 and 2019, but the precipitation, inflows from Lake Erie and Ottawa River flows in 1993 were also not as significant as the record-breaking amounts we observed in 2017 and 2019.

How can you blame "climate change" when your charts show similar highs and lows in the lakes for 100 years? 

The record-breaking precipitation observed over the past several years in the Great Lakes and the Ottawa River watersheds was the main driver for the extraordinarily high water levels in recent years. Projections from models of climate change and the Great Lakes suggest more frequent times of very high or very low water levels, although its not possible to attribute a series of wet months or even years directly to a cause, such as a changing climate, as opposed to natural weather variation. Regardless, the wet years that were recently observed are consistent with what would be expected in a changing climate.

I remember very large beaches in the 60's on Lake Erie and Lake Ontario. Over the years many, many properties and cottages have disappeared. It's hard to believe you're not controlling the water levels considering your own charts of water levels. Can you explain?

The Boards are directed to control outflows from Lake Superior and Lake Ontario through regulation, which can have a modest impact on water levels, but water supplies are the primary driver of water level fluctuations over time. A severe drought in the 1960s led to low water levels in the Great Lakes region. It should also be noted that the capacity limitations of the connecting channels and the hydraulic structures within those channels cannot accommodate the record-breaking water supplies we have observed enter the lakes in 2017 and 2019. Therefore, when water supplies exceed the outflow capacity of regulation and natural channel capacity, the Lakes will rise and this is not within the control of the Boards nor the IJC.

I am on Georgian Bay (Lake Huron). Last fall we sustained shoreline damage as a result of high winds and high water levels. Do you have a prediction for how high we can expect the water levels to get in Lake Huron this year, and can we expect more high wind events?

It is likely that the July levels we observed are the maximum levels we will see this year based on seasonal trends. The maximum recorded level most recently observed was 177.47 m (582.26 ft) on July 20th. Lake levels on Michigan-Huron are expected to fall gradually through August and the rest of the year, but are likely to remain near their seasonal highs over the next several months. Unfortunately, wind events, which tend to be limited in summer months, can also be particularly severe in late fall and early winter throughout the Great Lakes. Making adequate preparations for such events should be considered when addressing risk to shoreline properties and infrastructure.

Has the IJC considered partnering with communications portals such as "Great Lakes NOW" a Michigan based organization that produces short, informative videos on topical Great Lakes issues. This topic of water levels and the limited role of IJC could be a very informative series of videos. By the way, your story map about the entire Great Lakes system is a great product....need more of them for consumption by the general public. Happy to chat more on this idea.

Yes, the IJC has collaborated with Great Lakes Now and other media consortiums on the production of segments about Great Lakes water quality and water levels. For example, IJC Commissioner Rob Sisson was recently a panelist when Great Lakes Now launched Water Damage (episode 1016).

The shoreline mitigation measures destroy wetlands and wildlife habitat and take away the natural beauty of the shoreline. Is there any thought to augmentation of the current controls on water levels to make them more effective? Do you have any recognition of the impacts of climate change and global warming?

Shoreline mitigation measures can have environmental impacts, which is one reason why measures such as shoreline hardening are regulated in Canada and the US. The construction of new dams and channel enlargements have been studied extensively over the years, but such studies have consistently found that further regulation is not feasible and the extensive dredging of the St. Clair and other rivers needed to increase outflow capacities would severely harm river environments. One of the main reasons is that further regulation would transfer extreme conditions from one part of the system to another, causing particularly large impacts in the St. Lawrence River. The IJC does evaluate the performance of the existing regulation plans through an adaptive management process, part of which includes taking emerging knowledge about climate trends and projected climate changes into account. 

You are mentioning June outflows all the time and ignoring the higher-than-normal outflows (over plan 2012) from December to March. Can you please justify that?

The Lake Superior Board was granted deviation authority from December 2019 through April 2020. A gate setting equivalent to one gate fully open was maintained over the winter months instead of the typical winter setting equivalent to one-half gate open. This allowed a small amount of additional flow to be released through the St. Marys Rapids to offset expected and potential unscheduled reductions in flows at the hydropower plants that often occur in challenging winter conditions. The effects of this deviation amounted to a reduction of approximately 0.7 cm on Lake Superior and an increase of 0.5 cm on Lake Michigan-Huron. 

Past IJC studies have indicated that turning down Ogoki and Long Lac diversions can lower Michigan Huron by 4.5 inches. Why does your slide show it would only lower levels by .2 inches? This is not what was indicated in the 1993 water levels study. Chair Corwin, we do need to "take the edge off" any way we can. Please!

The slide shows the combined effect of the diversions. The combined effects of the Long Lac, Ogoki and Chicago diversions and the Welland Canal have been to permanently raise Lake Superior by an average of 2.1 centimeters (0.8 inches), lower Lakes Michigan-Huron by 0.6 cm (0.2 in), lower Lake Erie by 10 cm (4 in) and raise Lake Ontario by 2.4 cm (1 in), according to the IJC’s 1985 Great Lakes Diversions and Consumptive Uses report. The 1993 Levels Reference Study report to the IJC on crisis conditions found that the maximum theoretical effect of manipulating (i.e., modifying) the diversions would be to lower Michigan and Huron by 3.5 inches after two years of operation. In its 1993 report to the Governments of Canada and the US, the IJC recommended that the Governments determine the negative impacts of changing the flow rates before reaching conclusions about using the diversions as crisis relief measures.

Who is tracking and what are the potential implications of the shoreline and other high water and erosion control and flooding mitigation projects that are rapidly being implemented around the Great Lakes

To some extent, the GLAM Committee is collecting impact data to shoreline property owners and municipalities through surveys and meetings with local officials. Through this process, some data on mitigation efforts has been recorded. However, it is not the IJC's nor Boards responsibility to track and compile a comprehensive list of projects throughout the Great Lakes. We are unaware if there is an agency that tracks all such projects.

What has happened to all the tailings that were produced from the tunnels dug at and under Niagara Falls in the last few years

Ontario Power Generation completed construction of a tunnel in 2013 to allow diversion of water from the Niagara River to the Sir Adam Beck Generating Stations for production of hydro power. This diversion takes water from the Niagara River at the Chippawa Grass Island Pool upstream of Niagara Falls and puts the diverted water back into the Niagara River at the Sir Adam Beck Generating Station downstream of Niagara Falls. The tunnel or the material taken from the tunnel, has no impact on the levels of the Great Lakes.

Inasmuch that Lake Ontario is tidal it would appear that the regulators don’t have a handle on what they should be doing

There is no ocean tidal influence on Lake Ontario water levels. There are local changes in water levels caused by wind direction, duration and speed.

What much is climate change responsible for high water levels?

We know we have had sequences of very wet years in the past, notably in the 70's, 80's and 90's. Record precipitation observed in 2017 and 2019 were the main drivers of the high water levels.  Although it is not possible to attribute a series of wet months or even years directly to a changing climate, projections from models of the future climate over the Great Lakes suggest more frequent times of very high or very low levels. Thus, the wet years such as those recently observed are consistent with what could be expected in a changing climate.

Is there any data, and where can I find it, regarding additional river flow supply going into the great lakes from the increasing number of residential communities that have drainage that goes into the rivers and into the great lakes and how much of an increase is this causing versus where we were a hundred years ago if such river flow data exists? 

There isn't a summary that would address your concern, however the USGS provides a historical record of flow data on many rivers throughout the system. Further information can be found at https://waterdata.usgs.gov/nwis/rt.

How can you say that Plan 2012 balances water levels between lakes Superior and Michigan Huron, while over the last six months Superior has been below its record highs and Michigan-Huron have established new record highs but the outflows into the St. Marys River have been consistently above average?  If the plan was working properly why aren't outflows from Lake Superior conspicuously below average?

Currently, the levels of both lakes Superior and Michigan-Huron remain well above their averages, so it should not be expected that the Lake Superior outflow would necessarily be below average. Under both natural and regulated conditions, high lake levels generally correspond to high outflows. If the Lake Superior level were below its average and Michigan-Huron above average then the Lake Superior outflow would be below average. Nonetheless, owing to dryer conditions around Lake Superior over the past several months, Lake Superior's level is - relatively speaking - lower than Michigan-Huron's at this time. As a result, Plan 2012 is balancing the lakes Superior and Michigan-Huron levels by reducing the Lake Superior outflow below the natural outflow (or pre-project) that would occur at these Lake Superior levels, thereby reducing the level of Lake Michigan-Huron to closer to average.

You refer to pre-project flows for Lake Superior regulation conditions. Does this mean natural flows before the 1914 Orders of Approvals or other starting points?  How can property owners compare Plan 2012 outflows to these pre-project flow estimates?

Yes, the pre-project flow is the flow that would occur if the outlet of Lake Superior was as it was in 1887, prior to any significant human alterations. The outflow equation for the pre-project or 1887 relationship is listed in condition 5 b. in the IJC's 2014 Orders of Approval (https://ijc.org/sites/default/files/2014%20Supplementary%20Order%20of%20Approval.pdf)

Water levels in St. Clair Township, Brights Grove and throughout the St Clair River area and Lake Huron are so high that we are seeing flooding of homes, shoreline erosion, etc. What is the plan to address it?

The IJC is aware of the impacts of high water levels in the St. Clair River and elsewhere in the Great Lakes system. The construction of new dams and channel modifications has been studied extensively, but the studies have consistently found that while such modifications can transfer the damages from one part of the system to another, there is no feasible way to prevent high lake levels and eliminate coastal impacts.

Are there legal provisions in place for acquiring vulnerable properties at market rates, in other words that allow for avoiding high expropriation costs?

Some jurisdictions, such as the Province of Quebec, are offering financial incentives encouraging property owners who have been flooded to relocate rather than rebuild. However, such programs are relatively new and are not widespread.

Since 2020 is measuring up to be similar to 2018, and 2019 saw record high water levels on Lake Ontario. As a part of the adaptive part of the Plan 2014 will there be a more defined commitment to lower Lake Ontario below prescribed Plan 2014 regulation in an attempt to not repeat 2019 levels in 2021? 

The Board constantly monitors water level conditions and considers the forecasted risk of high water levels in the spring. This risk is considered when discussing whether any regulatory action could help to lower the risk of high water levels occurring. Should the forecasted risk of seeing high waters be significant, then that would be an indication for the Board to seek approval of deviation actions that could help to lower that risk. It should be noted that there always has been, and there always will be, the risk of high water levels recurring, and there is no regulatory action that can be taken to eliminate the flooding risk outright.

Is there any planning by IJC for contentious situations if nature does not cooperate in the cycle of precipitation to a lower level? and are you prepared financially to act on it?

The IJC's Boards have regulated Lake Superior and Lake Ontario outflows to reduce the impacts of the extreme-high inflows that have been experienced in recent years, but our capacity to control water levels is relatively small compared to the natural factors that influence water levels.

Three fourths of my back yard have been underwater since this spring. Last year it was about half underwater. It is getting up to the house foundation with a stiff SE wind. I am at a loss as far as what to do and procedures involved regarding permits, etc.

We empathize with property owners who have suffered financial and emotional stress, and have done what we are able to do to reduce water levels. Along with you, we hope that natural conditions result in lower water levels next year. Unfortunately, there is no getting around the fact that extremely high water levels will occur again - whether in two years or two hundred - though nobody is able to predict when this will happen since it depends on the weather.

Did the lakes have a more regular high water cycle before increased carbon emissions, or has it always been erratic? Have there been any attempts to ask First Nations and other Indigenous people about historical accounts?

Great Lakes water levels have always fluctuated, and periods of high water have caused damaging impacts to shoreline interests before. Though we did see record breaking water levels in 2017 and 2019, sequences of high water years occurred in the 50's, 70's, 80's and 90's too. Coordination with First Nations was done during the development of the new regulation plans and the IJC continues to work with First Nations to better learn from their historical knowledge of the Great Lakes Basin. 

What is considered an improvement to the plan?  Reduce the Lake height upstream priority by only inches or volume dumped down stream resulting in floods in CAD?

We are looking for any opportunities, however small they may be, that would reduce the overall impacts of high water levels. As you note, there is also a balance between upstream and downstream impacts. Any change in how this balance is achieved must be accepted by both Canada and the United States.

The down stream is you pointed out is extremes not as balanced when you try to rapidly change the upstream water level. Is the priority to keep the water in the lakes or drain the lakes as the improvement priority?

The priority is to ensure that any negative impacts from high water events are evenly balanced between upstream and downstream shoreline interests. It is not solely to lower Lake Ontario nor to keep vulnerable downstream areas from flooding, but to do both to the extent possible.

When will the GLAM Committee finish its initial evaluation of potential adjustments to Plan 2014, and will the results of its study be made available to the public?  

The GLAM Committee is aiming to report its findings to the Board on decision criteria for deviating from Plan 2014 flows under extreme high water conditions in the fall of 2021. We expect that the findings will be made public in approximately the same timeframe. However, it is important to recognize that the GLAM Committee provides information to the Board as it becomes available and, for example, such information assisted the Board with regulating flows in the spring of 2020.

Is there a theoretical maximum level for the middle lakes?

Maximum values for Great Lake levels are primarily driven by how wet conditions are in the Great Lakes basin, which in turn is determined by precipitation and climate. Our period-of-record data set of lake levels provides an estimate for maximum levels, based on historical conditions of the Great Lakes since 1918. These values can be found at http://www.tides.gc.ca/C&A/network_means-eng.html.

Has the US and/or Canada considered a reference to IJC under the provisions of the BWT to specifically address/mitigate high water conditions and make recommendations to governments on what additional measures might be undertaken (e.g., changes in control structures)?

The construction of new dams and channel modifications have been studied extensively over the years, both in response to references from the US and Canada, and during the review of existing IJC orders of approval. Multi-lake regulation was most recently reported on by the Upper Great Lakes Study Board in 2012. Such studies have consistently found that further regulation is not feasible. One of the main reasons is that further regulation would transfer extreme conditions from one part of the system to another, causing particularly large impacts in the St. Lawrence River. 

There are other human interferences in the Great Lakes system at Long Lac/Ogoki and the Chicago diversion. In addition, it is theoretically possible to adjust the flow down the Welland canal. Has any thought been given to coordinating all these current and potential control points under one coordinated agency?

Lake Superior and Lake Ontario outflows are regulated internationally and the IJC's Boards already coordinate information about their operations. The flows at Long Lac/Ogoki, Chicago and the Welland Canal are operated under domestic authorities in each country for purposes other than Great Lakes water levels regulation. Canada and the US would need to reach agreement before control over these diversions would be ceded to one coordinating agency.

On the St. Mary's slide currently displayed, what was the configuration before any human intervention? Was it just the rapids?

Yes, in its natural state the outlet of Lake Superior was the St Marys Rapids, which were modified significantly by the construction of the locks, canals and hydropower plants that exist today.

Is the St. Clair River channel ever cleared out for sediment constriction of output channel? 

The only portions of the of the St. Clair River that have sediment routinely removed through dredging operations are within the authorized navigation channels used for commercial shipping. These channels are maintained to a set authorized depth that was most recently set in the 1960's. These dredging operations only maintain the authorized depth, and do not deepen the channels any further than that over time.

Please explain net effect of O/L diversion over 70 years on raising Lake Superior levels and consequently Lakes MH? 

The combined effects of the Long Lac, Ogoki and Chicago diversions and the Welland Canal have been to permanently raise Lake Superior by an average of 2.1 centimeters (0.8 inches), lower Lakes Michigan-Huron by 0.6 cm (0.2 in), lower Lake Erie by 10 cm (4 in) and raise Lake Ontario by 2.4 cm (1 in), according to the IJC’s 1985 Great Lakes Diversions and Consumptive Uses report.

At looking at the precipitation map you see a steady increase of rainfall
How do you explain the all-time lows in 2013?

Perhaps the resolution of the precipitation map was not clear during the presentation, but the late-90s/early-2000s were drier, as was 2012, prior to the low water levels that occurred later that year and at the start of 2013. Additionally, increasing temperatures have been recorded in the Great Lakes region. Starting in 1998 and continuing through 2012, temperatures were especially warm, causing increased evaporation and resulting in lower lake levels during that time.

How about the Illinois river in Chicago?
Isn’t that also an outlet for Lake Michigan and Huron?

The Chicago diversion is under a strict US Supreme court order to not exceed 91 cubic meters/second or 3,200 cubic feet per second. If it were increased above this, impacts would be a loss of flood storage on the Chicago Area Waterway System, creating a risk of flooding downtown Chicago, a halt to navigation on the waterways, erosion of the banks, ecological degradation of the system, and significant life and safety issues downtown (or any locale adjacent to the Chicago River).

Can the Lake Michigan outflow be directed to the Chicago River and Ship Canal?

The Chicago diversion is under a strict US Supreme court order to not exceed 91 cubic meters/ sec or 3,200 cubic feet per second. If it were increased above this, impacts would be a loss of flood storage on the Chicago Area Waterway System, creating a risk of flooding downtown Chicago, a halt to navigation on the waterways, erosion of the banks, ecological degradation of the system, and significant life and safety issues downtown (or any locale adjacent to the Chicago River).

What is the estimated amount of water increase to the water levels in Michigan Huron?

Lake Michigan-Huron levels peaked on July 20th and are expected to continue falling gradually over the next few months.

The method of corrective control was questioned in the JOINT HEARING BEFORE THE NEW YORK STATE SENATE STANDING COMMITTEE ON ENVIRONMENTAL CONSERVATION
Page 170-172 of the report is quoted below:
“Under Plan 2014, we are not allowed to deviate from the calculated value” -- so the computer program “runs the show” -- unless we go above the trigger level or below the lower trigger level; except, we can deviate for a request from the River.
If a ship is coming into Montreal, then we're  allowed to deviate. And, again, we cannot deviate until we actually hit the trigger.
We could have a perfect forecast, a month in advance, that we're going to exceed the trigger.
We're not allowed to do anything, until we hit it.
And that's in the order, and it says that can't be changed unless they go back to the governments and get approval. So, that's a hard-and-fast.

Question: If it takes years to make correction to levels by flow rates why is this ignored?

The passage you cite focuses only on deviations from Plan 2014. However, Plan 2014 takes corrective action by adjusting Lake Ontario outflows in response to water levels, inflows from upstream other current and forecasted conditions. This occurs in real time. It does not take years. In addition, under exceptional conditions, the IJC may also grant authority for the Board to deviate from Plan 2014 flows, even when Lake Ontario is below the trigger levels specified in the order. The IJC granted such authority to the Board in 2017 and 2019. Nonetheless, all of the actions that the IJC and Board are able to take have less influence on water levels than natural factors, such as precipitation, temperature and evaporation, none of which can be accurately predicted or controlled. In the future, if inflows to Lake Ontario and the St. Lawrence River are as high as they were in 2017 and 2019, flooding will occur again regardless of what preventive or corrective actions are taken by the IJC or Board.

Does the Chicago diversion equal the Ogoki diversion?  Has the Ogoki diversion increased since inception?

No. The Chicago Diversion is set to 91 m^3/s out of Lake Michigan-Huron and the Ogoki Diversion has added an average of 114 m^3/s to Lake Superior since 1943. Operation of the Ogoki diversion has not been modified since it's inception.

How can 60 continual months of above average flows and increasing flows through the St. Mary’s River when Lake Michigan is 34 inches above LTA while Lake Superior is only 8 inches above LTA be evidence of the goal to "attempt to balance high and low levels" of these 2 bodies of water?

Currently, the levels of both lakes Superior and Michigan-Huron remain well above their averages. Under both natural and regulated conditions, high lake levels generally correspond to high outflows. Nonetheless, owing to dryer conditions around Lake Superior over the past several months, Lake Superior's level is - relatively speaking - lower than Michigan-Huron's at this time. As a result, Plan 2012 is balancing the lakes Superior and Michigan-Huron levels by reducing the Lake Superior outflow below the natural outflow (or pre-project) that would occur at these Lake Superior levels, thereby reducing the level of Lake Michigan-Huron to closer to average.

Putting aside the existing operational guidelines of Plan 2012 and concern for other Great Lake interests, is there sufficient engineering capacity between Lake Superior and Michigan/Huron to decrease the levels of Lake Michigan/Huron beyond the Plans existing operation? If so, how much of a decrease?

The IJC would not just put aside the existing operational guidelines of Plan 2012 and concern for other Great Lakes interests. However, in theory, all gates at the compensating works could be closed, all hydropower operations could be shut down, and all lockages through the locks could be ended to essentially stop all flow from leaving Lake Superior, creating catastrophic consequences, but temporarily eliminating almost all flow into Michigan-Huron from Lake Superior. This would have the effect of lowering Lake Michigan-Huron by a little less than 5 cm (2 inches), on average, after a month's time. Lake Superior would rise a bit less than 7 cm (3 inches) per month, and eventually the structures would be overtopped as Lake Superior's level rose and uncontrolled flow would resume.

We are constantly, even today, told the capacity to lower Lake Michigan/Huron by decreasing the flows out of Superior is "minimal", "limited", "only centimeters", however if the flows were reduced starting a few years ago when Michigan/Huron reached crisis levels how many inches would Michigan/Huron be lower today?

Lake Superior water levels have also been near or above record high levels during this period. The amount that Lake Michigan-Huron would have been reduced would depend on the amount that flow was reduced and for how long. To lower Lake Michigan-Huron by just 1 cm (0.4 inches) requires flows to be reduced by 400 cubic meters per second, or about 20% of the average St. Marys River flow. In addition, if flows from Lake Superior had been reduced years ago, this would have caused its record setting levels of last year to be even higher, resulting in more severe flood and erosion damage around that lake. During periods of severe wet weather regulation of outflows attempts to balance high water conditions, upstream on Lake Superior and downstream on Lake Michigan-Huron

I'm tired of hearing answers regarding closing off diversions into LS and flow out of LS as limited in effect and results can’t be seen over night. Why can you folks at the controls not understand the significance of taking action at some point in time with the patience to allow the impacts to accumulate to achieve a few to several inches lowering over time of several months or years? A few to several inches is MAJOR since the stage damage curve is exponential. In other words, with regard to water depth, the few inches between my mouth and my nose are minimal but surely very significant with regard to my ability to breathe while standing in deep water.

Studies have shown that reversing the Long Lac and Ogoki diversions would provide some relief, lowering the level of Lake Michigan by 2-3 inches. But this relief would take roughly two years to achieve; in that time, weather would have a much larger influence on water levels. Also, such an action would have significant negative impacts within the basins that the diversions are located, including damage to public infrastructure, shoreline erosion, interruption of tourism, impacts to First Nations hunting grounds, ecosystem and biological harm, and the reduction of production of electricity. The combined effects of the Long Lac, Ogoki and Chicago diversions and the Welland Canal have been to permanently raise Lake Superior by an average of 2.1 centimeters (0.8 inches), lower Lakes Michigan-Huron by 0.6 cm (0.2 in), lower Lake Erie by 10 cm (4 in) and raise Lake Ontario by 2.4 cm (1 in), according to the IJC’s 1985 Great Lakes Diversions and Consumptive Uses report. 

Do you predict water levels to be higher on the St. Lawrence River than in 2019 in future?  I have a cottage above the Moses Saunders Dam in Brockville Ontario. We were inches from flooding in 2017 and 2019.

Unfortunately, your property will remain vulnerable to flooding during similarly wet periods in the future and it is possible that levels at Brockville could exceed those of 2019 at some time in the future. Please look to your local municipal officials and conservation authority experts who can best direct you on improving your property's resiliency to the extent possible.

Currently, there is a record of temperature in Siberia territories, with unimaginable T on three digits, my question is: how can we mitigate the effects of this sort of Temperatures over our Great Lakes, we know all of this is due to the Climate Change, but how can we, locally, mitigate this effect on our Great Lakes. In my case I am really concerned about Erie. Thank you!

Unfortunately, there is no reliable method to mitigate extraordinarily high temperatures and their impacts on the Lakes.

How do you account for the fact that using the components method of calculating net basin supplies Michigan Huron for 3 of the past 4 years has had below average net basin supplies?
And have you notices that Lakes Michigan Huron and Georgian Bay have not had a normal fall decline?
 

The components method net basin supply (NBS) data set being referred to here carries a high degree of uncertainty, relying on a limited network of precipitation observations, runoff stations and modelled evaporation. Studies and research to better understand and improve these datasets is ongoing. The residuals method of computing NBS uses water levels and connecting channel flows to compute net basin supplies. It also has sources of uncertainty, but is generally considered more accurate. It shows that NBS has been consistently above average over the last several years. This is consistent with some of the more advanced precipitation datasets available. The decline in water levels over this past fall was much less than normal on Michigan-Huron, however NBS during those months was above average, which led to the very small seasonal decline.

How much can GLAM or Boards take action on water levels based on anticipated rises or falls rather then trigger points, when it often too late for meaningful relief?
 

We do not yet have the ability to forecast the weather months in advance. Taking action on anticipated rises and falls can have unintended impacts, especially when you consider the uncertainty associated with forecasted weather conditions and water levels. The International Lake Ontario - St. Lawrence River Board uses shorter-term (1 to 4 week), probabilistic forecasts, accounting for uncertainty, to aid in its decision-making. In 2019 and 2020, the Board successfully removed some extra water prior to spring 2020 due to the deviation actions it implemented, which were in part based on forecasted conditions, but favorable weather conditions were of primary importance in allowing these actions to be effective. However, basing regulatory strategy on long-term forecasted weather and water levels is not feasible given current limits on accuracy and inherent uncertainty in forecast results. 

With every foot of water, the lakes go up, that’s 19.65 trillion gallons of water. With the lakes going up several feet, does the increased heat capacity of this massive amount of excess water influence the weather systems that are in turn, causing more precipitation? Is it a vicious cycle at this point?

At this point we are not aware of any research that shows a linkage in increased water volume in the Great Lakes basin causing increases in precipitation.

Why is the "mean" level for great lakes participation on your slide only for the years 1901-2000 and not 1901 to 2020?  Doesn't this distort the overall reference to historical average? 

The period 1901-2000 is simply the default setting on NOAA's website, where this data and graphic were obtained (https://www.ncdc.noaa.gov/cag/regional/time-series). Modifying the period of record to 1901-2019 does not meaningfully change the results or overall conclusion that it has been extremely wet in recent years.

What is the confidence level of the accuracy of the precipitation data basin wide extending all the way back to 1895?  It is difficult to believe that as far back as 1895 the precipitation data is very reliable basin wide and may be susceptible to undue influence of a small number of precipitation collectors. 

Technology and networks of precipitation stations have indeed varied over time, and we agree, precipitation data from long ago carries a larger degree of uncertainty than more recent datasets, and users of the data should be careful about how it is used. We do believe it can still be helpful in identifying long terms trends.

What are adaption measures that are being recommended, or being considered for extreme high or extreme low waters?

Many jurisdictions across the Great Lakes region are undertaking a range of adaptations to accommodate a wider range of water levels such as protecting roads, sewers and water treatment infrastructure, rebuilding boat launches and other recreational facilities, using dredged material to build up barrier beaches, etc. 

How can property owners in Canada access compensation for damage and costly repairs to their shorelines/properties? USA (Gov Cuomo) has posted that funds are being distributed to US property owners. We property owners on Lake Ontario have just completed costly repairs to our shoreline for the THIRD TIME since 2017.

It is our understanding that providing assistance to property owners would be under the jurisdiction of provincial authorities.

Are the property owners responsible for hiring an engineer to come up with a resiliency plan and if so, how does the DEC fit into the plan?

Our understanding is that state programs will provide general information and guidance documents about the options for shoreline protection and required permits. However, it is generally advisable to hire a qualified coastal engineer to recommend solutions that are appropriate for conditions that are specific to the individual property.

How much of an impact do you think the Chicago River diversions into lake Michigan have on the system overall and is there anything to be done about that?

The combined effects of the Long Lac, Ogoki and Chicago diversions and the Welland Canal have been to permanently raise Lake Superior by an average of 2.1 centimeters (0.8 inches), lower Lakes Michigan-Huron by 0.6 cm (0.2 in), lower Lake Erie by 10 cm (4 in) and raise Lake Ontario by 2.4 cm (1 in), according to the IJC’s 1985 Great Lakes Diversions and Consumptive Uses report.

My neighbour is an engineer from Holland who has lots of experience regulating water levels. He says that the solution for Georgian Bay is to dredge the Detroit River. Thoughts?

Deepening of the St. Clair and Detroit Rivers would reduce the water levels of Michigan-Huron (this has occurred in the past during past dredging projects for commercial navigation). However, this action would also have long-term, permanent impacts of reducing Michigan-Huron levels and increasing water levels on Lake Erie. Lake Erie is also very high, currently, with similar impacts to shoreline property there as on Lake Michigan-Huron. Also, during future extreme low water periods, water levels on Michigan-Huron would then be exacerbated. Such a project would also be extremely expensive and impacts would need to be well studied.

The Georgian Bay Forever organization opines that there are problems with the St. Clair River conveyance that are causing restrictions with flow and therefore causing higher water levels on Huron/Michigan. Do you have any comment on this assertion?

The US Army Corps of Engineers runs a comprehensive program of monitoring for conveyance change in the St. Clair and Detroit Rivers. Over the last 15 years repeat bathymetric data has been collected and analyzed for changes in the channel bottom. Flows have also been monitored closely for any potential unexpected changes. No significant changes have been identified in the channel conveyance to date. An updated analysis is currently underway and should be ready later next year.

Is there an opportunity to acquire some learning from other country's that are faced with similar flooding issues as Lake Ontario?

Yes, there are lessons to be learned from the technical and social approaches used to reduce the impacts of flooding and erosion in different countries, however, the differences in circumstances must also be taken into account.

What role does climate change play in fluctuating water levels?

We know we have had sequences of very wet years in the past, notably in the 70's, 80's and 90's. Record precipitation observed over the past several years has been the main driver of the high water levels.  Although it is not possible to attribute a series of wet months or even years directly to a changing climate, projections from models of the future climate over the Great Lakes suggest more frequent times of very high or very low levels. Thus, the wet years such as those recently observed are consistent with what could be expected in a changing climate.

Is the outflow from Lake Erie into Lake Ontario measured on a daily basis and where would one find that data?  And the same for the Ottawa River - is that measured daily to Montreal?

The International Niagara Committee prepares annual reports containing the flows out of Lake Ontario. These reports can be provided by the US and Canadian governments in electronic format. The Government of Canada also makes daily flow data for the Niagara River at Fort Erie (02HA013) available through the web page https://wateroffice.ec.gc.ca/index_e.html. Daily flows for the Ottawa River at Carillon are listed at http://www.ottawariver.ca/conditions/?display=river.

Is there a board for Lake Michigan Huron Erie

No, not specifically. The International Lake Superior Board of Control takes levels of Lakes Michigan-Huron into account when regulating outflows from Lake Superior.  Otherwise, there are no control structures that regulate flows between Lake Michigan-Huron and Lake St. Clair or between Lake St. Clair and Lake Erie, and therefore, there are no regulation plans that needs IJC/Board oversight.  

If 2190 meters cubed/second is the average outflow of LS what is the minimum viable outflow of LS?

The long-term average outflow from Lake Superior is 2,120 m3/s for the 1900-2019 period of record. The record minimum monthly mean outflow of 1,160 m3/s occurred in September 1955. There is also a requirement in the current regulation plan (Lake Superior Regulation Plan 2012) that the minimum flow every fifth June must be 1,700 m3/s to satisfy Lake Sturgeon spawning requirements. 

The weather explanation for the high water levels in the Middle Lakes is not convincing. You need to improve that. There is a lot of data that could b presented

Precipitation data was presented showing increasing, and in fact, record precipitation around the Great Lakes basin in recent years. This is the primary cause of record water levels in recent years.

Does the US Army Core of Engineers have any influence over water levels in the Great Lakes?

The IJC has direct authority over regulation of the projects that have limited influence on water levels on the Great Lakes. This authority is granted by the 1909 Boundary Waters Treaty. The IJC has created Boards through its Orders and Directives to oversee the execution of its regulation plans. The International Superior Board of Control and the International Lake Ontario-St. Lawrence River Board regulate outflows from the Compensating Works in the St. Marys River between Lake Superior and Lake Michigan-Huron and the Moses-Saunders Dam on the St. Lawrence River. The US Army Corps of Engineers and Environment and Climate Change Canada contribute technical experts to support and advise (and, in some cases, chair) these Boards and aid in their decision-making processes. These Boards must make all decisions by consensus and USACE and ECCC are not the entities delegated the responsibility for operating the hydraulic structures that can influence lake levels.

With the river bottom elevation being lower on the Canadian side of the Niagara River, the Weir, although assisting in the direction of the water to the hydroelectric plant. At the same time, with the river bottom being lower on the Canadian side, forcing the water around the Weir causes the increased height of the CGIP, ultimately, over a long period of time, increases Lakes Erie, and others upstream. (Much like the statement about the flow of the Moses Saunders Dam impacting the flow out of Lake Ontario.)

The Niagara River has a tremendous capacity to move water through it. The International Niagara Control Works was designed to control water levels locally upstream of Niagara Falls to divert water from the river to the hydro plants for power production. Due to the relatively small size of the INCW and the high capacity for the Niagara River to move water through it, which is controlled by the very steep river bed where Lake Erie flows into the river, the INCW has no impact on levels either in Lake Ontario or Lake Erie or upstream. In June the average level of the pool upstream of the INCW was 3.88 m (12.7 feet) below the level of Lake Erie. This provides a constant hydraulic gradient that allows for very high flow through the Niagara River. As well the Niagara River drops over Niagara Falls which is 50 m (150 feet), so the level of Lake Ontario has no effect on the level of Lake Erie.

There are conversations about the Niagara Control Weir being taken private. A private company that impacts the citizens of Canada and the United States. Is this accurate?  Does it make sense to make this private?
 

The International Niagara Control Works is operated by the Power Entities (Ontario Power Generation and New York Power Authority) of USA and Canada. Its operation must be done within the limits of the International Niagara Board of Control's 1993 Directive, which provides limits for the protection of the public. There are no discussions on privatization occurring within the Board or IJC.

If the continued answer is that the controls on the Niagara River do not impact the level of Lake Erie, then why not remove the 2500 ft. weir except for that needed only for the hydropower plant water inlets?

The International Niagara Control Works is already constructed so that its only function is to divert water to the Power Entities for power generation according to the 1950 Niagara River Diversion Treaty. It only spans a little more than halfway across the Niagara River, leaving the rest of the river open for water to pass.

How can we do shoreline protection on the west side of southern Georgian Bay when we've experienced 6-foot waves at 3-second intervals as happened last year?

Conditions at the particular location must be taken into account when considering the effectiveness of different shoreline protection designs. We suggest you consult a qualified coastal engineer. However, some properties may be vulnerable to the point where shoreline protection is not feasible.

Since the dredging of the St. Clair River, which was to increase the natural flow, has this area begun to be filled in with silt flows from the high water levels? If this is the case what, if anything, can or has been done to lower this level again?

To clarify, the St. Clair River was deepened in the past to allow larger commercial ships to transit the Great Lakes system, not to allow additional water out. Those navigation channels are maintained to a set depth and as material deposits into these channels it is removed. The US Army Corps of Engineers runs a comprehensive program of monitoring for conveyance change in the St. Clair and Detroit Rivers. Over the last 15 years repeat bathymetric data has been collected and analyzed for changes in the channel bottom. Flows have also been monitored closely for any potential unexpected changes. No significant changes have been identified in the channel conveyance to date. An updated analysis is currently underway and should be ready later next year.

Approximately what percentage of annual water level changes in Lake Michigan-Huron can be attributed to outflow from Lake Superior?

The influence on water levels from Lake Superior outflows as compared to total NBS can vary greatly month to month. When outflows are high and NBS is dry, there will be a much greater influence on water levels than when outflows are low and NBS is wet. That said, on average it is safe to think about outflow as having a 5-15% influence on water levels. Another way to consider this contribution is to compare the long-term average St. Marys River outflow to the other inflow/outflow components. This comparison shows that the St. Marys outflow consists of approximately 14% of total supplies to Michigan-Huron. 

Do increased outflows into Lake Michigan-Huron contribute to higher precipitation levels in the Michigan-Huron basin?

Lake Superior outflows into Lake Michigan-Huron have no effect on precipitation. Increased outflows from Lake Superior do increase water levels in Lake Michigan-Huron, so this is taken into consideration when regulating these outflows.

Can you please summarize specific steps government agencies in both countries are doing to help lakeshore home owners protect their properties, both current and planned, especially as related to Lake MI.

Guidance and assistance to home owners are generally provided at the state level. We would recommend that you contact the coastal zone management program in the state where you live.

is adding more controls where they don't currently exist, an answer? 

The construction of new dams and channel modifications have been studied extensively over the years, both in response to references from the US and Canada, and during the review of existing IJC orders of approval. Multi-lake regulation was most recently reported on by the Upper Great Lakes Study Board in 2012. Such studies have consistently found that further regulation is not feasible. One of the main reasons is that further regulation would transfer extreme conditions from one part of the system to another, causing particularly large impacts in the St. Lawrence River. 

What is the downside to lower Ontario levels?

Impacts of low Lake Ontario levels can include limitations to some boating access points, dangerous boating conditions due to shallow water, reduced depths in the shipping channel and commercial docks, reductions in hydropower generation, impacts to fish and wildlife, water quality issues, and potential exposure of municipal and industrial water supply intakes and sewage outfalls.

The presentation did not mention basin diversion at Chicago?  Why not and what effect on lake levels would opening the Chicago Locks have?

The Chicago diversion is under a strict US Supreme court order to not exceed 91 cubic meters/ sec or 3,200 cubic feet per second. If it were increased above this, impacts would be a loss of flood storage on the Chicago Area Waterway System, creating a risk of flooding downtown Chicago, a halt to navigation on the waterways, erosion of the banks, ecological degradation of the system, and significant life and safety issues downtown (or any locale adjacent to the Chicago River).

Did we learn today that the lake levels can be and are influenced by man's settings at outflows? 

The IJC boards have some influence over lake levels as a result of regulation of outflows from Lake Superior and Lake Ontario. However, the main drivers remain the weather-driven, uncontrolled inflows into each of these two lakes and the downstream extents of their influence.

Is there a website location or data that is shared regarding the daily positioning of the gates, up, down, partially engaged of the Niagara Control Weir? I presume that there is a chart or spreadsheet keeping this data.

The International Niagara Control Works is operated by the Power Entities (Ontario Power Generation and New York Power Authority) of USA and Canada. Its operation must be done within the limits of the International Niagara Board's 1993 Directive, which sets limits on the water levels upstream of the INCW for the protection of the pubic. Information on the operation of INCW can be found in the International Niagara Board of Control's Semi-Annual Progress Reports on the board's web site at https://www.ijc.org/en/nbc/library/reports