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The good news! Water levels are going down and by July are predicted to be about 10 in or 26cm below the levels of July 2020.

See: https://lre-wm.usace.army.mil/ForecastData/BulletinGraphics/MBOGLWL-mich_hrn.pdf

This decline is right in line with the future lake predictions in our Baird Report III that can be found here.

This is based to some extent of the longer-term higher temperature predictions for the both the US and Canadian sides of the Great Lakes;

The not so good news.

There has been a lot of talk about whether the IJC and the International Lake Superior Board of Control are, in fact, meeting their criterion  to “balance both upstream and downstream conditions”. So our hydraulic engineer went to work using USACE data and recently completed the following analysis:

It is obvious from this graph that, if the IJC had followed their own Plan 2012 balancing criterion, our water levels would be even 20cm or 8in lower than they are right now. BUT the IJC issued many orders for deviations to increase the flow through the St. Marys River – deviations that clearly benefited hydropower and kept Lake Superior within a 4-foot range while our levels moved close to a 7-foot range. Just where is the equity in these IJC deviation-order decisions? It is shocking that the IJC made no official mention of these deviations, thereby misleading other Georgian Bay organizations to believe that Plan 2012 was followed to the letter and was doing a splendid job of meeting the required “balancing” interests upstream and downstream. Only Georgian Bay Great Lakes Foundation seems to be aware of the 20 cm (8”) that MH would be lower if the increased-flow deviations from Plan 2012 had not been ordered by the IJC.

Further, Plan 2012  inherently ignores the non-stationarity of outflows through the St. Clair-Detroit river system. Changes in flows in this part of the system are not explicitly factored into Plan 2012 computations, along with inflows from the Long Lac-Ogoki diversions into Lake Superior.

Here are the basic hydraulic fundamentals for Regulation Plan 2012.

The fundamental hydraulic equation that governs the water level of Lake Michigan-Huron (MH) is:

Note that the mean value of the St. Clair River flow is 5,225 cms compared to the St. Marys River discharge from Lake Superior of 2,127cms; hence the influence on Lake MH level is 2.45 stronger for the St. Clair River as opposed to the influence of the St. Marys River. The problem is that, with no human-induced control over the size of the outflow through the St. Clair River, its flows vary from 4,000 cms to over 7,000 cms; however the IJC’s International Lake Superior Board of Control uses a fixed 5,225 cms flow. This standardization is not imposed on any of the other Control Boards’ equations, where monthly averages are used.

The figure below shows a record of water levels for Lake Superior (left) and Lake MH (right) for the period of 2014 to 2021, during which Plan 2012 has been in operation. Both water level plots also show the respective long-term monthly averages (LTA).

The graphs clearly show the influence of extremely high net basin supply starting in 2014. The following facts are obvious:

1. In 2014, Lake Superior quickly exceeded its long-term average and then kept rising for the next 7 years, ending up some 30 cm above its LTA in 2021. 
2. Lake MH started well below its long-term average but crossed above it in 2014. It then kept rising and reached 177.46 m IGLD 85, virtually equal to the 1986 all-time record high water level, and about 80 cm above its LTA in 2021. 
3. 80 cm is 2.7 times greater than 30 cm. Plan 2012 (like Plan 1977A before it) was supposed to ‘balance’ the lakes (Lake Superior & MH) by trying to have their levels an equal distance (actually in terms of standard deviations) from the LTA.

In the graphs below, the left graph shows the St. Marys River Flow (SMR) – the Lake Superior monthly discharge as determined by Plan 2012. The right graph shows the St. Clair River (SCR) flow. This flow is determined by the natural self-regulating hydraulic forces, whereby the SCR flow responds to the Lake MH water level and resulting hydraulic head, which is opposed by the conveyance of the SCR. This, in turn, results in an eventual Lake MH level equilibrium that achieves a long-term water balance between the total basin supply and the total outflow. Both of the flow graphs are compared to their value in 2014.

4. Plan 2012 Lake Superior discharge is the SMR flows including the IJC ordered deviations. It fluctuated between 2000 and 3100 cms, depending on when Lake Superior met, was less than, or exceeded its LTA (by up to 30 cm).   There is, however, no evidence that Plan 2012’s compulsory “Lake balancing algorithm” at any time reduced the SMR discharge to reflect the fact that Lake MH had exceeded its LTA by as much as 80 cm. In effect, Plan 2012 acted as a simple level controller for Lake Superior, while ignoring Lake MH.
5. Additionally, the IJC directed the International Lake Superior Board of Control to deviate many times from Regulation Plan 2012. Those deviations to increase the discharge mainly benefited Lake Superior by keeping its levels within the 4-foot range, while Michigan/Huron levels set a new record high, with a range now of close to 7 feet.  Where is the equity in the IJC’s management of our water levels?
6. The biggest factor that kept Lake MH in check was thankfully the natural increase in SCR flow.
7. But what if those high flows have caused erosion of the St. Clair River’s bed? No one knows! If that riverbed has eroded as a result of such extremely high flows, then when the high supplies decline but the high flows through the eroded SCR continue, our MH water levels will plummet and possibly set new lows again.
8. Plan 2012 ignores the SCR flow, in spite of the fact that recent developments with the SCR Acoustic Doppler velocity meter have resulted in an accurate and reliable flow measurement.  The graph below shows that, in fact, between 2014 and 2021, the SCR flow increased by 80% and was one of the largest contributors to the Lake MH water balance.

To complicate matters, in late January 2021, the lower SCR and Lake St. Clair froze solid, resulting in a 3,000 cms reduction in the SCR flow from 7,000 cms to 4,000 cms:

Clearly, Plan 2012 should be capable of taking such an event accurately into account.

Conclusion

It is clear that the International Joint Commission by ignoring the St. Clair River discharge in Plan 2012 has failed to design an effective Lake Superior discharge control strategy, in which an effective lake level balancing objective can be structured, in spite of the fact that the flow from the St. Marys River is less than 40% of the total basin supply of Lake MH.

It is also clear that the middle lakes levels could in fact be much better and responsibly managed than they currently are. To conclude otherwise shows the lack of hydraulic engineering expertise required to understand Great Lakes levels, flows and management attempts.

The IJC’s Great Lakes Adaptive Management (GLAM) committee is now undertaking a review of Plan 2012 behind closed doors with no technically qualified public oversight. Since the approach to managing Plan 2012 has failed to meet a critical criterion; namely, to “balance both upstream and downstream conditions”, we strongly recommend that this review be undertaken by a committee that is independent of the GLAM Committee, since they were involved in designing Plan 2012. And we further recommend that public technical oversight be ensured by the inclusion of technically qualified representatives from shoreline organizations and municipalities who have been most significantly impacted by the failures of Regulation Plan 2012.  Such representatives need to have strong relative background and formal technical qualifications in this area. To date, none of that is happening.

How long does this lack of proper oversight over our valuable Lake Huron/Georgian Bay finite resources including wetlands have to endure?  It is an issue that merits urgent positive action by our Federal governments.

What can you do?

1. You can tell your Federal MP that you want the IJC to appoint technically qualified shoreline representatives to their review of Regulation Plan 2012, and GBGLF has such personnel.
2. Support GBGLF financially, to continue to stay on top of these complex issues that impact the entire Bay.