In the face of two years of record-setting high water on Lake Ontario and the St. Lawrence River, the Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee was directed by the International Joint Commission (IJC) to conduct an expedited review of Plan 2014, the outflow management regulations for Lake Ontario (see Appendix 2).

This is the report on Phase 1 of that expedited review. This first phase was given a narrow and urgent focus: Exploring whether there are new and better ways for the International Lake Ontario-St. Lawrence River Board (Board) to respond to a repeat of the exceptional hydrologic conditions and extreme high water levels on Lake Ontario and the St. Lawrence River that caused severe impacts in 2017 and 2019. To achieve this, the GLAM Committee has built on existing information and compiled a great deal of new information about the impact of extreme high water. The GLAM Committee has also worked closely with the Board to learn more about the practices it uses to address extreme high-water events on Lake Ontario and the St. Lawrence River by adjusting outflows, overriding, or deviating from, the provisions of Plan 2014. That information has been used to produce an innovative interactive tool that will provide the Board with valuable insight into potential risks and potential benefits when it responds to future extreme water events.

The GLAM Committee was established by the IJC in January 2015 to systematically review outflow management plans from Lake Ontario and Lake Superior (IJC, 2015). The committee was given a 15-year timetable to complete its reviews — but the IJC advanced the timetable for the review of the Lake Ontario-St. Lawrence River outflow regulations, known as Plan 2014, because some members of the public and some elected officials questioned whether the plan and Board had responded appropriately to the repeated rounds of extreme high water (GLAM, 2018; Global News, 2020; Auburn Citizen, 2020).

The decision in February 2020 to focus Phase 1 of the expedited review on trying to find more effective ways for the Board to deviate to help reduce flooding was driven by memory of the two flood years on Lake Ontario and the St. Lawrence River. As well, there were record or near-record water levels on the upper Great Lakes, including Lake Erie, which feeds through the Niagara River and the Welland Canal directly into Lake Ontario (ECCC, 2020). There are no dams on Lake Erie or the Niagara River to control the flow into Lake Ontario (INBC, 2021). With continued high unregulated inflow from Lake Erie, there was an elevated risk of similar or even worse extreme high water on Lake Ontario in coming years. Considering this, the IJC felt that the first step it should take was to help the Board refine its decision-making as soon as practical in case high water were to recur in the near term.

As Board members told the glam Committee during preparation of this report, Board members have felt the need for more information on the impacts of their deviation decisions during recent high-water years and have found it challenging to make these decisions without full knowledge of the risks and uncertainties associated with their decisions (GLAM, 2020a). The Board members’ concerns about limited information are of great interest to the IJC and the various uses and interests, particularly given the unprecedented nature of the recent flood events and the potential future impact of climate change.

Even before Lake Ontario’s waters began to recede from their peak levels in 2017 and 2019, the GLAM Committee and its partners had started gathering data on the impacts of high water on six uses and interests throughout the Lake Ontario and St. Lawrence River system as defined by the IJC in the report on Plan 2014 (IJC, 2014). Detailed information was collected on shoreline damage, commercial-shipping effects and impacts to the river ecosystem, hydropower, municipal water intakes and recreational boating (GLAM, 2018).

More recently, the GLAM Committee has begun gathering information on impacts on Indigenous communities on the St. Lawrence River and Lake Ontario. The GLAM Committee asked Board members what information is needed to support decision-making. glam Committee members and associates studied the regulatory framework and explored alternative deviation strategies that could be employed. A Public Advisory Group (PAG), made up of representatives from a broad range of sectors and interests (Table 1) on Lake Ontario and the St. Lawrence River, was established and has provided the glam Committee with useful advice and input on the effects of extreme high water on their constituencies (IJC, 2020b). This new data and insight have allowed the GLAM Committee to develop an interactive tool that will synthesize and present a wealth of objective data to the Board about the tradeoffs across interests and geographies that are inherent in many deviation decisions. The Decision Support Tool (DST) will systematically provide Board members with information that will help them compare the impacts of possible deviations on the various uses and interests. Uncertainties about upcoming hydrologic conditions can be addressed by testing deviation strategies under a variety of possible future water supplies.

During extreme water-level situations on Lake Ontario the flow releases may be set off-regulation plan and still be in compliance with the 2016 Order. The Board is authorized to use its discretion to set flows in such conditions and to deviate from the usual rules and limits in the approved plan to provide relief to the degree possible upstream and downstream. Its deviations can alter the water level — in the realm of centimeters or inches, not meters or feet — by adjusting the flows out of Lake Ontario and through the St. Lawrence River. Water supply conditions were such that the flow releases were off-plan repeatedly during the recent extreme high water; discretionary deviation decisions dictated the outflow through the St. Lawrence River for approximately half of the time from January 2017 to December 2020 (Figure 1, see more detailed discussion in Section 3.0).

While the DST should be an effective aid, it will neither make deviations decisions for the Board nor give the Board new powers to address threatening extreme water levels. Often when the Board is called upon to act, serious impacts will have already begun (Figure 2). The Board has little leeway; it can take steps to lessen those impacts slightly but it cannot make them disappear.

Studies1 by the Board (ILOSLRB, 2017), the glam Committee (GLAM, 2018), the IJC and others have shown that extraordinarily heavy and persistent precipitation and other natural occurrences led to the high water level in 2017, 2019 and early 2020 (Figure 3). Those studies have demonstrated that neither Plan 2014 nor any other regulatory plan could have prevented the flood damage that occurred.

However, abiding concern about the impacts of extreme high water in 2017 and 2019 caused the IJC and the two national governments to reassess the need to analyze Plan 2014 in the near term. As a result, Canada and the United States provided funding for an expedited review of the plan.

In the winter of 2019-2020, continued high inflows from Lake Erie and high local Lake Ontario-St. Lawrence River basin water supplies kept levels of Lake Ontario near or above the extreme high water levels and the point where Board deviations from Plan 2014 were authorized. Favorable weather-driven ice conditions on the river enabled deviations from the plan and release of extraordinarily high winter outflows from Lake Ontario that helped keep the winter lake level from rising higher. Lake levels began to moderate in March 2020 and, primarily due to a lack of spring precipitation and snowmelt runoff in the basin, lake and river levels peaked below the high thresholds in 2020.

In a telling example of the uncertainty about future water supplies that the Board faces, Lake Ontario fluctuated through 2021. The lake’s level quickly fell below the long-term average in the early part of the year and an unusual spring drought began in parts of the lake-river basin. Just months after concern had centered on possible high water, Lake Ontario levels declined to the point that the Board was authorized to begin deviating to address low-water conditions. In late May 2021, the Board reduced outflow from Lake Ontario below those specified by Plan 2014 to provide all possible relief from the potential impacts on municipal water intakes, navigation and powerpurposes, upstream and downstream. Nonetheless, Lakes Michigan, Huron and Erie remained well above average in the summer of 2021 and the drought in the Lake Ontario basin broke with several months of above-average precipitation. In early October, LakeOntario’s level moved back above the long-term average point (ECCC, 2021).

In light of this, and given the variability and uncertainty in Lake Ontario water supplies and other hydrologic factors, the rationale for focusing Phase 1 on the Board’s ability to address extreme high water through deviations remains well-founded. The low water levels in the spring and early summer of 2021 and the rapid recovery from those low levels also point to the importance of adaptive management to address changing conditions over the short and long term. The purpose of Phase 1 was not to end up with an overall recommendation for how to deviate, nor to provide a system optimization. Rather, it was to gather, process and present the information needed by the Board to assist them with their decision-making.

A broader exploration of Plan 2014 under both high and low water extremes and the need for any modifications will be the subject of the Phase 2 report on the expedited review of the plan. Work on Phase 2 of the expedited review is tentatively scheduled to be completed in the fourth quarter of 2024.

More on the expedited review of Plan 2014: https://ijc.org/en/glam/expedited-review

The Lake Ontario-St. Lawrence River is a complex, dynamic system with many unique natural features and with engineered structures that are used to regulate flows through the interconnected lake and river system. The International Joint Commission (IJC) and their International Lake Ontario-St. Lawrence River Board (Board) serve to manage the outflows of Lake Ontario in accordance with Orders of Approval issued by the IJC. Outflows are managed under widely varying hydrological and climatic conditions, including changes in precipitation and temperature, which are two primary drivers of water levels in the system. The intent of outflow management is to achieve expected outcomes in consideration of a wide range of interests, and to the benefit of both Canada and the US.

The Lake Ontario-St. Lawrence River system, for the purposes of outflow regulation, extends from the lower Niagara River through Lake Ontario and as far down the St. Lawrence River as Trois-Rivières, Quebec, which is about 140 km (87 mi.) downstream of Montréal (Figure 4).

Lake Ontario is the easternmost and lowest of the five interconnected Great Lakes (Figure 5); the accumulated water from the four upper lakes enters Lake Ontario through the Niagara River and the Welland Canal. By surface area, Lake Ontario is the 12th largest freshwater lake on Earth (19,011 km² or 7,340 mi²), but is the smallest of the five Great Lakes. By volume it is the fourth smallest, ahead of Lake Erie. Lake Ontario is 311 km (193 mi) long and 85 km (53 mi) wide at its widest. The border between the United States and Canada runs roughly through its center, with 54 percent of its shoreline in Canada (ccglbhhd, 1977).

The Great Lakes represent the largest freshwater system in the world. With abundant biodiversity, they are home to approximately 3,500 species of plants and animals and provide 20 percent of the world’s freshwater supply (NOAA, https://www.noaa.gov/education/resource-collections/freshwater/great-lakes-ecoregion).

As the traditional territory and Treaty territory for diverse Indigenous Peoples including the Anishinaabe, the Haudenosaunee, the Wendat, the Métis and others, the Great Lakes have always been a center of habitation and trade.

Today, about 8.75 million people live in municipalities that abut Lake Ontario, and tens of thousands of households are located on or near the lake shore. The greatest concentration of shoreline development is in the heavily urbanized Greater Golden Horseshoe region stretching from Niagara Falls around the western end of the lake through Toronto, Canada’s largest city. Rochester, New York, has the largest concentration of shoreline residents on the United States side (Figure 4).

Lake Ontario empties into the St. Lawrence River, which by discharge volume is the 13th largest river in the world (Benke et al., 2005). The St. Lawrence River runs 1,191 km (740 mi) before emptying into the Atlantic Ocean; the first 450 km (280 mi), from the head of the river at Cape Vincent, New York and Kingston, Ontario downstream to Trois-Rivières, Quebec, is influenced by changes in outflow from Lake Ontario as addressed by Plan 2014. The stretch of the St. Lawrence River immediately upstream of the Moses-Saunders Power Dam located at Cornwall, Ontario and Massena, New York is known as Lake St. Lawrence, which was created when the Moses-Saunders Dam went into operation in 1958. Lake St. Lawrence serves as a forebay for the dam.

At Montréal, the St. Lawrence River is joined by its largest tributary, the Ottawa River, which drains a basin more than twice the size as that of Lake Ontario. During the spring melt, large quantities of water that are stored in the snowpack are released and can combine with rainfall, which can lead to heavy spring flow and flooding. This is called a freshet. Generally there are two distinct flood peaks on the Ottawa River in the spring, about three weeks apart. The first spring flood peak in the Ottawa River originates from unregulated flows from its southern tributaries. The second peak results from a combination of high flows from the northern tributaries together with flows from headwater areas, and is partially regulated. The spring freshet can have a big impact on the levels and flows on the lower St. Lawrence River, however, the IJC has no oversight of that river’s flow and does not set conditions for operation of the dams in the Ottawa River basin (https://ottawariver.ca).

Approximately 4.7 million people live in municipalities that border the St. Lawrence River between Cape Vincent and Trois-Rivières. The bulk of the shoreline lies in Quebec and the dominant population center is Montréal, Canada’s second-largest city. The river elevation naturally dropped roughly 69 m (226 ft) between Cape Vincent and Montréal, and originally several rapids in that section of the river had made it impassable to large vessels. However, this fall of water offered substantial hydropower potential. After decades of discussion between officials in Canada and the United States, in 1952 the two nations submitted an application for a hydroelectric project to the IJC for approval in accordance with the Boundary Water Treaty of 1909. The design of the hydropower project that would straddle the St. Lawrence River near Cornwall, ON and Massena, NY was required to also facilitate the construction of the Seaway navigation system that was agreed to shortly afterwards by the two Governments. In October 1952 the project was approved (IJC, 1952).

Also in 1952, in the mid st of flooding on Lake Ontario, the two national governments asked the IJC to determine, “having regard for all other interests”, whether measures could be taken to regulate the level of Lake Ontario for the benefit of property owners on the shores Lake Ontario, “having in mind the order of precedence to be observed in the uses of boundary waters as provided in Article VIII of the Boundary Waters Treaty of 1909” (ILOBE, 1957). The Lake Ontario monthly average level had reached as high as 75.76 m (248.6 ft) in June of 1952, the historical maximum record. After several years of study, and government concurrence, the ijc approved a design range of Lake Ontario levels that would reduce the peak level by 0.24 m (0.8 ft), provided that natural water supplies were no more extreme than those experienced in the past (ILOBE, 1957). To enable this reduction in Lake Ontario levels for the benefit of shoreline property owners required additional dredging in parts of the upper St. Lawrence River to increase the outflow capacity while allowing safe velocities for navigation to be maintained. This added channel flow capacity would enable a “considerable decrease” in future Lake Ontario shore property damage but not enable all such damage to be eliminated (ILOBE, 1957), nor would it prevent greater shoreline damages if water supplies to the lake were more extreme than historical.

The 7-year construction of the hydropower project included the Moses-Saunders dam, the Long Sault Dam, the Iroquois Dam, the Massena Intake, and 18 km (11.2 mi) of dikes (Macfarlane, 2014). The channel enlargements in the river required removal of over 53,500,000 cubic metres (70,000,000 cubic yards) of material (Bryce, 1982). The construction of the project resulted in the generation capacity of 1,957 megawatts of hydropower, enough energy to meet the needs of about two million homes. The hydropower project, together with the locks and additional channel dredging of the Seaway project, allowed deep-water vessels to navigate the river, thus opening the Great Lakes to ocean-going freighters. Outflow regulation was enabled by the St. Lawrence hydropower project. The increased channel capacity of the upper St. Lawrence River together with the dams allowed both higher and lower than natural outflows to be released from Lake Ontario and provided a measure of flood mitigation.

A visual tour of the Lake Ontario-St. Lawrence River system: https://storymaps.arcgis.com/stories/3dfcb1b201cd4a9f9424719976beecf5

The IJC was created by the 1909 Boundary Waters Treaty between Canada and the United States and it is now considered one of the world’s oldest international organizations.

The IJC’s purpose is to prevent or resolve disputes over the uses of the lakes and rivers that either form part of the boundary, or cross the boundary, between Canada and the United States. In many cases, the IJC has been called upon by Governments to set conditions for the construction, operation and maintenance of any dam or diversion that would affect water levels and flows across the international boundary. The IJC has set conditions for uses, diversions and obstructions of boundary waters and recommended water apportionment measures on numerous bodies of water along the boundary or that cross the boundary between the United States and Canada and often maintains oversight of water outflows and water uses in those cases.

On the Great Lakes, the outflow of Lake Superior is regulated through dams on the St. Marys River and the outflow of Lake Ontario is regulated through dams on the St. Lawrence River under IJC supervision. The IJC has established boards to oversee the regulations at each of these locations. The IJC’s mission also includes ice management and the management of flows and levels in the Chippawa-Grass Island pool on the Niagara River as well as Great Lakes water-quality issues.

The IJC comprises three members from each country that are appointed by their federal governments. The IJC has a professional staff in United States and Canada numbering about three dozen and also relies on the support of government partner agencies in both countries.

The membership of the IJC can be found on the IJC website: https://ijc.org/en/who/people/commissioners

More on the Commission: www.ijc.org

The Board oversees the operations of Plan 2014 on Lake Ontario and the St. Lawrence River. This report has been prepared for use by the Board to help it carry out its mission and meet its obligations under the 2016 Supplementary Order of Approval (https://ijc.org/en/68a) and associated directives.

The Board consists of six members who are appointed by the IJC. Each national government nominates one member, as do the provinces of Quebec and Ontario and the state of New York. To maintain parity a sixth U.S. member is appointed by the IJC. All appointees are professionals with expertise in water-related matters. The Board is aided by an Interim Advisory Group, which is meant to ensure that Board members have benefit of input from a broad group of stakeholders. At present the advisory group comprises six individuals, three from the United States and three from Canada, who had served on the Board itself until a December 2020 restructuring.

The Board supervises the regular workings of Plan 2014, which responds automatically to fluctuating water supplies by increasing or decreasing the outflow from Lake Ontario through the Moses-Saunders Power Dam and at times of maintenance or to supplement flows, a dam at Long Sault on the St. Lawrence River (see Figure 10 in Section 2.7.3 for reference). The Board reports semi-annually to the IJC on their activities and water levels. The Board has a number of sub-committees and staff who support it. The roles and responsibilities of these groups are outlined on Figure 6 and further described on the Board’s website (https://ijc.org/en/loslrb/lake-ontario-st-lawrence-river-regulation).

Much of the time the Board’s role is to monitor outflows and water levels as they fluctuate up or down in response to inflows from Lake Erie and weather–driven water supplies and to ensure that the outflows from Lake Ontario are set in accordance with Plan 2014. When water supplies are such that the level in Lake Ontario rises or falls to pre-determined “trigger levels” that are laid out in the Directive on Operational Adjustments, Deviations and Extreme Conditions, (https://ijc.org/en/loslrb/who/directives/deviations) the works are to be operated to provide all possible relief upstream and downstream. The Board is authorized to use its discretion to set flows under extreme conditions and to deviate from the plan to help lessen the impact of extreme water levels. (The board that existed under the previous regulation plan had similar, though not identical, authority.)

When deviating in times of extreme low water, as it did in the spring and early summer of 2021, the 2016 Supplementary Order of Approval requires the Board to give priority to protecting municipal and industrial water intakes, commercial shipping and hydropower production. When deviating during times of extreme high water, the 2016 Order requires the Board to give priority to protecting riparians (shoreline property owners), with consideration given toward those who are upstream along Lake Ontario and the upper St. Lawrence River above the dams and downstream along the lower St. Lawrence River shore. The high-end “trigger levels” (refer to Figure 3) are the levels that are expected to be exceeded 2 percent of the time; the low-end “trigger levels” are points below which the level is expected to fall 10 percent of the time.

The interventions that are taken once “trigger levels” are reached are known as major deviations from the plan. Major deviations alter the rate of outflow to try to bring about a desired change in the water level on Lake Ontario or the St. Lawrence River. The Board’s authority to deviate from the plan remains active so long as the water level of Lake Ontario continues to be above the high-water “trigger levels” or below the low-water “trigger levels”.

As extreme water levels ease and there no longer is need for a major deviation, the Board is required to outline for the IJC its strategy for returning to Plan 2014 outflows. The Board also must consider whether it is beneficial to make outflow changes in the future to offset, or “pay back,” the water that was released from Lake Ontario beyond what Plan 2014 would have specified. (If the Board was dealing with a low-water situation, the same applies to any “extra” water that was held on Lake Ontario.) The IJC decides, based on recommendations from the Board, on a case-by-case basis, whether pay-back deviations are needed. This is most often based on the current conditions and forecasts. As an example, beginning in October, 2021 the Board increased Lake Ontario outflows by up to 200 m3/s (7,100 cfs) above the amount set by Plan 2014 for approximately eight weeks to return Lake Ontario’s water level to the level it would have been if the Board had not made outflow deviations earlier in the spring/early summer of that year (late May through mid-July), but had instead strictly followed those specified by Plan 2014. The effect of this was to try and reduce Lake Ontario water levels by 4 cm by mid-December, 2021 to offset the amount that had been added to the lake as a result of the earlier deviation when the low criterion H14 “trigger levels” had been crossed.

The Board also may engage in short-term “minor” deviations that aid one use or interest without unduly harming any others. For example, if conditions warrant the Board temporarily raises levels for a few days in the fall in the forebay of the dam so that boats on Lake St. Lawrence can be readily removed for the season.

Subject to the requirements of the 2016 Order, the IJC may also authorize the Board to temporarily make minor modifications to the regulated outflows under a section of the 2016 Supplementary Order of Approval known as Condition J. These authorizations allow the Board to temporarily make minor modifications or changes to the regulated outflows from Lake Ontario for the purpose of determining modifications or changes in the regulation plan that may be advisable. The Board is required to report to the IJC the results of such temporary changes or modifications, together with any recommendations arising from such, and the IJC may accept or reject any such recommendations.

In the winter of 2019-2020 and 2020-2021, the IJC authorized the Board under Condition J to test viability of outflows that were greater than the plan’s winter operational limits provided they had little or no negative impact on other interests such as ice formation.

Deviation under any circumstances can be difficult given the complexities and uncertainties of the system. For example, increasing outflow to reduce flooding impacts on the Lake Ontario shoreline can increase the risk of flooding on some parts of the St. Lawrence River shoreline downstream of the dams. At the same time, those increased outflows can also cause water levels to plummet on other parts of the St. Lawrence River, such as Lake St. Lawrence. Conversely, large reductions in outflows result in large and rapid water level rises on Lake St. Lawrence and a corresponding drop in levels downstream of the dams (refer to Figure 27 and discussion in Section 3.2.2).

The deviation process, then, is a balancing act in which the Board must be mindful of the impact of its decisions not just on shoreline properties but on other uses and interests such as commercial navigation, the lake and river ecosystems and the need for stable ice cover on sensitive sections of the river as outlined in the 2016 Supplementary Order of Approval and the Directive on Operational Adjustments, Deviations and Extreme Conditions. This delicate give-and-take can lead to differences of opinion among parties who believe their interest or region was shortchanged by a deviation decision.

As was made clear by the experience in 2017 and 2019-2020, no deviation strategy or any other regulation action can prevent extreme high water in the face of unpredictable excessive precipitation, late snowmelt and other confounding factors such as high inflows from the Ottawa River in the spring (refer to Section 3.2.2 for more discussion on factors that complicate deviation decisions).

More on the Board: https://ijc.org/en/loslrb

The Great Lakes–St. Lawrence River Adaptive Management (GLAM) Committee was created by the IJC in January 2015. Through its directive (https://ijc.org/en/glam/who/directive), the Committee is charged with evaluating and supporting the outflow regulation plans for Lake Ontario and Lake Superior, and the management of water levels and flows in the Niagara River (specifically the Chippawa-Grass Island Pool). The GLAM Committee reports to the Boards that are responsible for those operations. This expedited review of the Lake Ontario management plan is the first such review to be concluded by the GLAM Committee. The GLAM Committee is made up of nine technical experts from each country appointed by the IJC, plus supporting secretaries.

As its name indicates, the GLAM Committee employs adaptive management — an approach that replaces static oversight with a dynamic process. The committee employs monitoring, modeling and analysis of new evidence on a continuing, iterative basis to recommend ways to improve the outflow regulation plans and adapt them to changing circumstances, including climate change. The GLAM Committee developed a short and long-term strategy document (GLAM, 2020b) to guide the adaptive management process and the expedited review of Plan 2014. The strategy outlines the critical components in the adaptive management process as well as the priorities for Phase 1 and Phase 2 of the expedited review of Plan 2014. The strategy was modified to address feedback provided to the IJC within the US Government Accountability Office report (gao-20-529, July 2020).

More on the Committee: https://ijc.org/en/glam

In May 2020, the IJC appointed an 18-member Public Advisory Group (PAG) to help the GLAM Committee in Phase 1 of the expedited review of Plan 2014. The group’s 18 members, drawn from First Nations, citizen associations, business and recreational groups, environmental advocacy organizations, and local government entities, represent the uses and interests on Lake Ontario and the St. Lawrence River. They began twice-monthly virtual meetings in June 2020.

Members serve in a voluntary capacity and have contributed significant time to attend about two dozen virtual meetings, many jointly with GLAM Committee and Board staff, and others separately. The PAG was tasked with advising the GLAM Committee on the information, tools and criteria used to assist the Board with deviation decisions. The PAG brought transparency to the process and ensured that the Board received the most pertinent information to assist it with decision-making, something encouraged by the US Government Accountability Office in their July 2020 report (GAO-20-529, 2020). The PAG did not have direct access or influence on the Board’s decisions, but its members provided valuable input about the impact of high water on the sectors and interests they represent and aided greatly in the development of the Decision Support Tool (DST). In the process, they gained a greater understanding and empathy for the issues and experiences of the other interests and regions and the complexity of the Lake Ontario-St. Lawrence River system.

The PAG consisted of people representing the following organizations or parties: Ault Island residents (Ontario); Beaconsfield Yacht Club (Quebec); Boating Ontario Association; Communauté métropolitaine de Montréal; Jefferson County Legislature (New York); Mohawk Council of Akwesasne; Montreal Port Authority/RUSL; New York Power Authority; Niagara County government (New York); Rochester-area shoreline residents (New York); St. Lawrence Seaway Pilots Association; Save our Sodus (New York); Save the River/Upper St. Lawrence Riverkeeper; The Nature Conservancy; Thousand Islands International Tourism Council; Union des producteurs agricoles; United Shoreline Ontario; Université du Québec à Trois-Rivières.

See Section 6.0 of this report for further discussion and visit: https://ijc.org/en/glam/expedited-review/public-involvement

An updated regulation plan for Lake Ontario and the adjoining portion of the St. Lawrence River, known as Plan 2014, was adopted by the IJC following concurrence from the Governments of Canada and the United States in its December 8, 2016 Supplementary Order of Approval. Releases of water in accordance with the 2016 Order and Plan 2014 were effective by the end of January 2017, and replaced the previous regulation plan (Plan 1958-D) which had been in use since 1963. Plan 2014, designed to accommodate a broader range of hydrologic conditions than its predecessor, was the culmination of over 16 years of study, public consultation and revision (IJC, 2014).

Fundamentally, the plan dictates how much water should be released from the Moses-Saunders Power Dam and its spillway, the Long Sault Dam, located about 160 km (100 mi) downstream of Lake Ontario’s eastern end. Plan 2014 is expected to maintain the water levels on Lake Ontario and the St. Lawrence River for much of the time within the range of water levels experienced over the past century. But neither it nor any other outflow management action can control water levels and prevent serious impacts when excessive precipitation, high inflows and other unforeseeable natural factors send waters to extreme high levels or when drought conditions send waters to extreme lows.

Plan 2014 typically prescribes the outflow from Lake Ontario on a week-to-week basis. Lake releases for Plan 2014 begin with a sliding rule curve based on the pre-project stage-discharge relationship such that as Lake Ontario levels or water supplies increase, outflows increase and as water levels or supplies decrease, outflows decrease (GLAM, 2018). The rule curve takes into account the present-day lake levels as well as the recent and estimated near-future supply of water in Lake Ontario. Under historical water supply conditions, the plan generally keeps the lake and river within the historic range of seasonal levels. The plan also was designed to achieve certain specific socioeconomic and environmental objectives, such as providing conditions that are beneficial to shoreline wetlands and recreational boating, while also complying with the Treaty order of precedence of uses3 and supporting other uses and interests (IJC, 2014).

The plan contains a series of limits that restrict or increase outflow from the lake under certain conditions to address specific uses and interests that can be affected by water levels and flows (IJC, 2014 – Annex B). These flow limits were developed from those used in Plan 1958-D, the former regulation plan, and what had been learned through operations with the decades of experience with deviations from that plan.

Plan 2014 Limits:

• The F Limit, which is designed to balance high water and the risk of flooding and erosion both upstream on Lake Ontario and downstream on the St. Lawrence River by adjusting Lake Ontario outflows to target increasingly higher water levels downstream at Lake St. Louis near Montréal as water levels upstream on Lake Ontario also increase (Table 2).
• The I Limit, which is meant to foster the establishment of a stable ice cover on portions of the St. Lawrence River in the wintertime. Stable ice cover prevents ice jams that can cause localized flooding and restrict flow in some areas to the point where municipal water intakes might become unusable.
• The L Limit, which is meant to keep levels and flow velocities in the St. Lawrence River within the range needed for safe navigation by commercial freighters (refer to Figure 23 in Section 3.1.2).
• The J Limit, which, unless another limit takes priority, restricts the scope of any increase or decrease in flow from one week to the next. The limit is meant to prevent rapid changes in currents or water levels in the St. Lawrence River.
• The M Limit, which applies during times of extreme low water by balancing levels between Lake Ontario and Lake St. Louis much like the F Limit does in times of high water. The M Limit acts to protect commercial shipping, hydropower production and water systems.

The limits are looked at collectively. If two limits apply at the same time, operations would be such as to respect both limits as much as possible.

As noted in Section 2.3, Plan 2014’s rule curve and limits may be deviated from under certain conditions as per the 2016 Supplementary Order of Approval and Directive on Operational Adjustments, Deviations and Extreme Conditions. When Lake Ontario’s water levels reach or exceed extreme high “trigger levels” and when Lake Ontario’s water levels reach or fall below the extreme low “trigger levels” major deviations are authorized. Other circumstances may necessitate operational adjustments or minor deviations. As discussed in the next section, the Board is obligated to abide by the conditions laid out in the 2016 Supplementary Order of Approval when making deviation decisions.

Relative to the regulation of Lake Ontario outflows, the inflow from the Ottawa River can have a profound effect on conditions in the lower St. Lawrence River. As noted earlier, the IJC and Board have no regulatory authority over the Ottawa River’s flow and do not control the dams in the Ottawa River basin. However, the Board works closely with the Canadian domestic Ottawa River Regulation Planning Board (https://ottawariver.ca) to integrate current and forecasted flows from the Ottawa River basin into the Board’s Lake Ontario outflow strategy.

While the storage capacity of reservoirs in the Ottawa River basin is relatively small compared to the water volume during the freshet time, the Ottawa River Regulation Planning Board takes every measure possible to try to optimize discharges from upstream reservoirs in order to reduce peak levels and flows along the Ottawa River. In doing so, peak flows into the St. Lawrence River are also reduced to a certain extent. While there is coordination and communication the two systems are operated independently.

More on Plan 2014:
• https://ijc.org/sites/default/files/Plan2014_CompendiumReport.pdf
• https://www.ijc.org/sites/default/files/2019-04/Plan2014.pdf

More on Frequently Asked Questions about Board operations: https://ijc.org/en/loslrb/causes-2017-high-water-event

More on the Ottawa River Regulation Planning Board: https://ottawariver.ca

Plan 2014, like the regulation plan before it, considers the needs of the groups of people and the business sectors that rely on Lake Ontario and the St. Lawrence River and have a strong interest in the water levels there. Elements of the plan rule curve and its limits were specifically designed to support and protect these uses and interests. Plan 2014 was also designed to provide for more natural variations of water levels of Lake Ontario and the St. Lawrence River relative to the previous regulation plan, which are needed to restore ecosystem health while continuing to moderate extreme high and low levels (ILOSLRSB, 2006; IJC, 2014).

The LOSLR Study Board Report (ILOSLRSB, 2006) identified six uses and interests in the region that live or work along the shore or use the lake and river for recreation or business and that potentially would be affected by new regulatory rules: (1) coastal development, (2) commercial navigation, (3) ecosystems, (4) hydropower, (5) municipal and industrial water use, and (6) recreational boating. Previous IJC studies (ILOSLRSB, 2006; IJC 2014) developed performance metrics to measure the impacts of water fluctuations on each of the six uses and interests and developed models to test the impacts in a variety of potential scenarios, including extreme high and low water levels and potential changes from climate change.

Because the Lake Ontario and the St. Lawrence River comprise a dynamic system whose levels ultimately are determined by the amounts of water that enter the system naturally, uses and interests can find themselves at risk from high or low water levels. Water levels and flows that benefits one interest can at times disadvantage another. Swimmers may appreciate lower water levels and wide sandy beaches, for example, while recreational boaters struggle to access docks or navigate between marinas and open water. Such situations can lead to tensions between the various interests and regions.

The order of precedence of uses which is followed in setting conditions for uses, obstructions and diversions of boundary waters dates to the 1909 Boundary Waters Treaty (https://www.ijc.org/en/who/mission/bwt) between the United States and Great Britain on behalf of Canada, which created the IJC. Article VIII of the Treaty lists, in order of precedence, three uses: domestic and sanitary purposes, navigation, and power production and irrigation. The Treaty states that “no use shall be permitted which tends materially to conflict with or restrain any other use which is given preference over it in this order of precedence.” In a separate paragraph of Article VIII, the Treaty says that approval of projects by the IJC is conditional on suitable and adequate provision for the protection and indemnification of all interests on the other side of the line which may be injured by a project.

The IJC’s 2016 Supplementary Order of Approval and associated directives provide the guidance and criteria for the Board to follow when making outflow decisions. The 2016 Order respects the order of precedence of uses and provides protection of interests as required by the Treaty including the requirement for flood protection identified in the 1956 Order.

More on the 2016 Supplementary Order of Approval: https://ijc.org/en/loslrb/who/orders

Members of First Nations, Tribal Nations and the Métis Nation have lived alongside Lake Ontario and the St. Lawrence River for millennia. Interacting with the natural world through a spirit of kinship, twinned with a sense of responsibility, Indigenous Peoples are intertwined with the region’s lands and water. As guardians of the landscape, they have relied on shorelines, rivers and wetlands of the Great Lakes-St. Lawrence River region for livelihood through traditional practices such as hunting, gathering, subsistence agriculture and fishing4. Lake Ontario along with the St. Lawrence River from Lake Ontario through to Trois Rivières is a vibrant watercourse of cultural heritage and economic exchange.

In total, the glam Committee identified twenty-two Indigenous Nations that have interest in the shorelines of Lake Ontario and the St. Lawrence River. Out of these, there are six communities that reside directly along the shoreline and 16 communities with an interest in the shorelines (Table 3).

The fluctuation of Lake Ontario and St. Lawrence River water levels does affect First Nations, Tribal Nations, and the Métis Nation in various ways, including impacts to their traditional and cultural practices and Indigenous rights. For example, outflow management decisions directly affect the Mohawks of Akwesasne as the Moses-Saunders and Long Sault dams are immediately upstream of the Akwesasne Mohawk Territory. This Mohawk community is represented by the Saint Regis Mohawk Tribe in the southern portion, the Mohawk Council of Akwesasne First Nation for the northern portion and the traditional leadership of the Mohawk Nation Council of Chiefs.

Additional Mohawk communities such as the Mohawks of the Bay of Quinte (within the Tyendinaga Mohawk Territory, Lake Ontario) (Figure 14), the Mohawks of Kahnawake (Lake St. Louis – St. Lawrence River), and Mohawks of Kanesatake (Lake of Two Mountains, where the Ottawa River meets the St. Lawrence River) are geographically situated along the Lake Ontario and St. Lawrence River shoreline (Figure 13). They are also affected by changing water levels and flows based on their location in the system.

Signed in 1909, the Boundary Waters Treaty between Canada and the United States does not explicitly reference Indigenous Nations or their relationship with the IJC. In any proceeding, inquiry, or matter before the IJC, however, the Treaty requires all interested parties be offered a convenient opportunity to be heard. For much of its early history, however, the IJC did not proactively invite Indigenous Nations to engage in its work, deferring instead to the governments of Canada and the United States to assume this role.

In recent decades, and at the request of governments, the IJC has sought to more formally include Indigenous perspectives in its activities. Across the United States-Canada boundary, the IJC has been actively engaging with First Nations, Tribal Nations, and the Métis Nation to ensure that their unique perspectives, ways of knowing and traditional knowledge are reflected in the work of the IJC. Through the work of the Expedited Review of Plan 2014, the glam Committee is engaging with First Nations, Tribal Nations and Métis Nations in the Lake Ontario-St. Lawrence River system, to initiate a conversation about how these Indigenous Nations experience changing lake levels and river flows. This work is seen as a first step in a longer-term effort to incorporate Indigenous knowledge and perspectives into the work of the GLAM Committee in support of the review of outflow regulation plans.

The Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee has examined the recent history of deviations to look for instances when different actions might have been possible. Committee representatives interviewed past and present International Lake Ontario – St. Lawrence River Board (Board) members and documented information gaps that contributed to uncertainty. The GLAM Committee documented the Board’s desire for more data on risks and rewards of deviation options. Knowing that the Board often faces questions about when to deviate from Plan 2014’s limits, which cap outflow in some circumstances, the GLAM Committee studied the history and function of those limits to explore alternative deviation possibilities.

The aim was to provide the Board with objective, relevant information to support its decision-making. This work, in which the Public Advisory Group (PAG) was also involved, was integral to the GLAM Committee’s creation of the Decision Support Tool (DST). The tool illustrates the benefits and harms that deviations might cause to various uses and interests and helps the Board better understand possible outcomes in the face of uncertainty about future water supplies.

The first four years that Plan 2014 was in use, beginning in January 2017 and ending in December 2020, was one of the most active periods in the 61-year history of the Board. Due to the extreme water supplies in 2017 and again in 2019 and early 2020, Board deviations governed outflows from Lake Ontario for 103 weeks, or nearly half the weeks in those four years (see Figure 1 in Section 1.2).

The Board employed several strategies to balance the interests of different sectors of the lake-river system. In both 2017 and 2019, in the face of damaging floods on the shorelines of Lake Ontario and both the upper and lower St. Lawrence River, the Board chose to follow the F Limit as it tried to balance the impacts of high water both upstream and downstream, even when it did have the authority to deviate from that limit. With heightened flood risk again in the spring of 2020, the Board, having the authority to deviate, chose to deviate above the lowest tiers of the F Limit in March.

As well, Board deviations from the L Limit significantly impacted the commercial shipping industry during both high-water events. In the summers of 2017 and 2019 when outflows were set above the L Limit, higher water velocities in the St. Lawrence River led the shipping authorities to institute mitigation measures such as speed, passing and draft restrictions, to ensure safe navigation (GLAM, 2018). In March 2020, the Seaway corporations chose to delay the opening of the shipping season, providing the Board an opportunity to maximize outflows from Lake Ontario in an effort to reduce the flood risk on the shore.

The Board’s deviation decisions were based on the best information available at the time and their experience and judgement. Inevitably, though, the deviation decisions stirred controversy along the shore of Lake Ontario and the St. Lawrence River, and among navigation interests, many of whom felt at times that the Board should have done more to help their interests or regions during the crises.

In both 2017 and 2019-2020, the Board hit decision points where it opted not to deviate from the plan’s built-in limits because members lacked enough certainty about whether they could deviate without disproportionately harming Lake Ontario or St. Lawrence River interests.

By definition, the F, L and I limits tend to apply when outflows are quite high, and the Board often finds itself considering deviating from a limit. But uncertainty about the repercussions of straying from these limits makes it more difficult for the Board to develop a deviation strategy. That is what led the GLAM Committee to study Plan 2014’s limits and gather more information on impacts — in hopes of finding alternative tactics that the Board can someday apply when it considers deviating from the limits.

Working together, the GLAM Committee and Board discussed and analyzed the Board’s previous deviations. The analysis focused not just on what deviations had been made but on why and how the deviation decisions were made, and looked into regulatory factors that came into play in making deviation decisions. The goal was to learn what metrics and other information should be included in the DST. Those discussions involved GLAM Committee members and their professional associates, the six current Board members, the six members of the Board’s Interim Advisory Group, and 18 members of the PAG who represent many of the uses and interests in the Lake Ontario and St. Lawrence River systems. The effort used shared vision planning, a collaborative approach for water management that was developed by the US Army Corps of Engineers (USACE) and has been used by the IJC and the glam Committee in the past.

Plan 2014 has three maximum outflow limits — the F, L and I limits — that often govern outflow to protect interests from excessive outflows during times of extreme high water. When criterion H14 “trigger levels” are reached as in 2017 and 2019-2020 (see Figure 3), and the Board has the authority to deviate, Board members must decide whether to override one of these limits despite a high degree of uncertainty about future conditions and without a great deal of information about potential outcomes of their decisions.

The GLAM Committee examined and documented deviations from the limits that have been made or considered in recent years. The committee also examined the origin and function of the limits and identified several possible options (Table 4) that are recommended for evaluation prior to future high or low water events. More details are provided below and in Sections 3.3.1, 3.3.2 and 3.3.3. These reviews and assessments will be considered in Phase 2 of the expedited review of Plan 2014 (GLAM, 2021a).

The prominence of the limits during periods of extreme high water was illustrated through an analysis by the GLAM Committee. It was found that from 2017 to 2020, if the Board had chosen not to deviate from Plan 2014, then Plan 2014’s rule curve would have set the outflows for just 32 of the 208 weeks, or 15 percent of that four-year period (Table 5). Each of the three main maximum outflow limits would have applied for longer periods; the L Limit would have controlled outflows for 110 weeks, the I Limit for 34 weeks and the F Limit for 30 weeks. Combined, maximum outflow limits would have applied for a total of 85 percent of that four-year period.

However, the Board did choose to deviate from the rules and limits of Plan 2014 in 103 of those 208 weeks. Based on actual operations, including the weeks when the outflows were governed by deviations from the plan rules, the distribution of the applicable rule or deviation is as shown in Table 6.

The GLAM Committee found that while the purpose of each of the limits was well understood, there was little specific information available to the Board about the impact on St. Lawrence River and Lake Ontario interests of exceeding those limits. When the limits were examined in detail, additional information was described that may be helpful in future deliberations by the Board. Further discussion about specific research undertaken is found in Section 4.0.

Recognizing the International Lake Ontario – St. Lawrence River Board (Board) needed more information about the comparative impacts of high and low water on the various uses and interests in the system to better make deviation decisions, the Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee proceeded in Phase 1 to gather data on impacts and has made great strides towards satisfying that need. The information, which the glam Committee gathered from a wide variety of sources, provides a fuller picture of the nature and extent of those high-water impacts on many uses and interests on Lake Ontario and the St. Lawrence River.

Thousands of shoreline residents and business owners, municipal officials, Indigenous community representatives, marina operators, shipping company representatives and others provided information directly or indirectly to support this effort, and in the process the GLAM Committee and the IJC were able to forge or cement relationships with many of these people and groups. These relationships and the data that was collected not only contribute to Phase 1 but will also support future work, including Phase 2 of the expedited review of Plan 2014. The following sections highlight some of the work that was undertaken for each of the uses and interests previously outlined in Section 2.7 and 2.8.

Municipal, industrial and private water and wastewater systems along Lake Ontario and the St. Lawrence River can be affected by both extremely high and extremely low water. The nature and extent of impacts is highly dependent on location and facility-specific characteristics making it challenging to undertake an overall assessment. High water impacts to municipal and industrial water systems were reported for locations along both the Lake Ontario and St. Lawrence River shoreline in 2017 (GLAM, 2018) and 2019. Low-water concerns in 2017 through 2020 have been most acute on Lake St. Lawrence where, as noted previously, high outflow through the Moses-Saunders dam can cause water levels just upstream in Lake St. Lawrence to decline steeply. Impacts can be experienced in other parts of the system during periods of extremely low levels, particularly along parts of the lower St. Lawrence River. However, those low-water impacts have not been a critical factor in high-water deviation decisions being considered in the Phase 1 effort.

The I Limit contains components meant to protect water intakes on Lake St. Lawrence by preventing water levels in that area from falling too low during winter months. The F Limit comes into play to protect shoreline buildings. Board deviations could affect water systems in numerous ways and the Phase 1 priority was to target specific data gathering to better understand high-water impacts across the Lake Ontario and St. Lawrence River system as well as specific low-water sensitivities on Lake St. Lawrence.

Commercial shipping is a significant industry in the Great Lakes region, with 3,000 vessels carrying an average total of 38 million tons of cargo through the Seaway each year (Martin Associates, 2020). The stretch from Montréal to Lake Ontario — the portion of the Seaway considered in this study — typically is open from early spring through late December. The Seaway closes over the winter months due to ice conditions and to allow maintenance to occur. Water in the St. Lawrence River normally is maintained at levels that are deep enough for large freight carriers and with currents slow enough that they can safely maneuver. The L Limit within Plan 2014 maintains outflows from Lake Ontario so that navigation can proceed safely.

The L Limit has been exceeded through Board deviation in times of extreme high water on Lake Ontario. In 2017 and 2019, a strategy was employed that allowed for releases by up to 5% above the L Limit while maintaining continuous navigation operations. The recent strategy allowed for an equivalent (or greater) amount of water released from what would have occurred with the 1993 intermittent flow strategy with fewer direct impacts to commercial navigation previously discussed in Section 3.3.2.

During periods of high water levels such as 2017 and 2019, very high outflows from Lake Ontario aimed at lowering its levels can cause currents in the St. Lawrence River that are strong enough to create unsafe conditions for ships navigating the river and increased risk of accidents. Outflows above the L Limit in 2017 and 2019 generated currents fast enough that large commercial vessels had to observe speed, meeting and passing restrictions in narrow sections of the St. Lawrence River and use tugboats for assistance in high-current areas (GLAM, 2018). Representatives from the shipping industry have indicated that mitigation measures put in place by the Seaway Corporations to manage the higher currents during such periods can increase operating costs for the Seaway corporations and their clients, especially if ship delays occur.

To support future Board deviation decisions under high water conditions, the glam Committee has been working to gather more information regarding the operational impacts associated with outflows above the L Limit based on the experiences in 2017 and 2019. In addition, the committee has undertaken an independent assessment of potential economic impacts to the navigation sector and the broader economy associated with ship delays at the beginning, middle, and end of the navigation season.

Operation of the hydroelectric plants along the St. Lawrence River that rely on Lake Ontario outflow to generate power can be affected by extreme high or low water. The Moses and Saunders hydroelectric plants and the Long Sault Dam at the foot of Lake St. Lawrence (refer to Figure 10 in Section 2.7.3) control the outflow from Lake Ontario. The Moses-Saunders installation can be affected by extreme high flows, which lowers the net operating head (the difference in elevation between the upstream and downstream side of the dam) and affect operations negatively. The turbines in these plants require a minimum net head to operate, which can limit the outflow. If an ice jam or constriction forms upstream this can reduce the upstream level and the net head. This is something the Board may take into account in its deviation strategy and the GLAM Committee focused its Phase 1 efforts on gathering additional information to inform operations during periods governed by the I Limit.

The impacts of extreme flows are lesser known on the two downstream facilities, Beauharnois and Coteau-Les Cedres (refer to Figure 10 in Section 2.7.3). Hydro-Québec, which operates the plants, has noted past problems with ice affecting the capacities of the channels supplying these two plants and the properties along the Coteau channels. A GLAM Committee analysis of Plan 2014 has recommended more study of the effects of high flow on the operations of these two plants (GLAM, 2021a). Both of the Hydro-Québec facilities are run-of-river, meaning that they do not have the capacity to store water on Lake St. Francis above the dam, and must pass all water that is received from the Moses-Saunders and Long Sault dams upstream plus the flow from local rivers draining into Lake St. Francis.

Board deviations during times of extreme high water are intended to provide relief to the people, businesses and public facilities and lands along the shorelines of Lake Ontario and the St. Lawrence River. Plan 2014’s limits and particularly the F Limit, which restrict outflow in varying ways, also have a direct impact on upstream or downstream shorelines. It was imperative, then, that the GLAM Committee collect additional detailed information about the impact of high water on shoreline interests so that Board members would have a better understanding of the effect of their deviations. In doing so, the GLAM Committee also had to take into account the fact that impacts can differ from one place to another under the same static water levels due to localized wind and wave conditions that drive up levels at some locations but not at others.

The Phase 1 effort obtained data on shoreline impacts in numerous ways including questionnaires for shoreline property owners, engagement with municipal staff and improved models to predict these water level impacts. The goal was to correlate the location and type of impacts from flooding and erosion with the water level to inform deviation decisions. This data also will be useful in Phase 2 of the expedited review, when it will be used to reassess the assumptions about high-water damage that were used in the creation of Plan 2014.

In recent years, the IJC has concluded, with governments concurrence, that the ecosystems of the St. Lawrence River and Lake Ontario should be taken into account by outflow regulations (IJC, 2014). As noted previously, it has been found that the previous regulation plan, which sought to suppress the natural range in water levels, had degraded diversity of species in shoreline wetlands and caused the wetlands to be dominated by cattails (IJC, 2014).

Plan 2014 was written in such a way as to allow more natural variations of water levels of Lake Ontario and the St. Lawrence River to reverse some of the harm to ecosystems while minimizing possible increased shoreline damages. While none of the limits or deviation guidance in Plan 2014 were specifically written to protect the lakes or river ecosystems, the Board must consider potential impacts when making deviation decisions.

Since its inception, the GLAM Committee has placed particular focus on tracking wetland vegetation in response to water level fluctuations. Wetlands are valuable features on Lake Ontario and the St. Lawrence River; they provide habitat for numerous animal and plant species, play an important role in nutrient and sediment dynamics and in some cases can influence shoreline flooding as vegetation serves to dissipate wave energy. However, the wetlands indicator developed in previous IJC studies (Wilcox et al, 2005; ILOSLRSB, 2006) is less suited to support comparison of short-term Board deviation decisions during periods of extreme high water levels. Instead, the GLAM Committee focused its Phase 1 ecosystem work in the Lake St. Lawrence area where deviation decisions, particularly in the winter months, can have a more substantial influence on water level conditions and potential ecosystem response as described in 4.5.1 below.

Recreational boating and shoreline tourism can be negatively impacted by extreme high water in several ways. It is valuable, therefore, to understand more about how and when those impacts come about. The glam Committee focused on two key tasks during Phase 1 of the expedited review, 1) integrating findings from a survey of marina and yacht clubs following the 2017 high water event, and 2) undertaking a general review of reported recreational boating and tourism impacts to guide future performance indicator development.

The construction of the St. Lawrence Seaway and the Moses-Saunders dam caused great disruption to the people of Akwesasne and their way of life and its operations continue to affect both the land and people of the Akwesasne Mohawk Territory as well as other Indigenous Nations. During the IJC’s International Lake Ontario-St. Lawrence River Study (ILOSLRSB, 2006), the Akwesasne Task Force on the Environment prepared a report highlighting specific aspects of outflow management that impact their community (Akwesasne Task Force on the Environment, 2004). Some of the issues highlighted increased impacts to fish species and mammals that require low velocity and/or stable water levels. Increased inundation of areas where traditional medicines grow were also flagged especially because these medicines are critical to the maintenance of Mohawk culture and of the relationships the Akwesasronon7 have with the entire ecosystem. Outside of this report from 2004, there was little documentation through the International Lake Ontario – St. Lawrence River Study on impacts to First Nations, Tribal Nations or the Métis Nation further upstream on the Lake Ontario shoreline or downstream of the Beauharnois Dam on the St. Lawrence River.

The 18-member Public Advisory Group (PAG), unpaid volunteers who met on a continuing basis between June 2020 and October 2021, were appointed by the IJC to promote public input and transparency.

The PAG was created so that representatives of groups that are directly affected by Board deviations could bring their insights into the impacts of extreme high water to the Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee. The glam Committee and the PAG worked together to understand and assess data about system impacts, a process that helped build trust in the ijc. It was also hoped that PAG members would communicate back their insights to their constituents, colleagues and neighbors, a goal that PAG members fulfilled as best they could.

The advisory group’s assigned role was to provide input on how extreme high-water impacts should be assessed and help the glam Committee consider what criteria should inform International Lake Ontario – St. Lawrence River Board (Board) decision-making on deviations. The PAG also was to help formulate a means of presenting this information to the Board, and to come up with ways to communicate with their constituents about what is being done to better inform the deviation decisions.

Many of the PAG’s sessions in 2020 were devoted to the nuts and bolts of Lake Ontario outflow regulation, which gave glam Committee officials a chance to explain how and why decisions are made and PAG members a chance to present perspectives on their priorities and interests and express concerns about the impact of those decisions. Through the intensive exchange, the advisory group built a deeper, shared understanding of the difficulties in managing this complex system, which involves accounting for differing costs, pain, protection, and benefits across geographies and interests and a set of difficult trade-offs within a risk-based management approach that is technically intensive, full of uncertainty, and difficult to communicate to stakeholders.

The PAG concluded its 2020 work by outlining what it had learned and identifying additional key issues concerning resilience and emergency response, which are outside the IJC’s mandate but are deemed critical to managing flooding along shorelines. The PAG also sought further clarity and transparency in regard to the IJC’s governance.

In 2021, much of the advisory group’s time was spent working on the Decision Support Tool (DST). The PAG assisted the glam Committee with laying out key objectives for the tool such as ensuring that all uses and interests are accounted for, and that the analysis of impacts is multi-dimensional and evidence based. The PAG recognized that tradeoff decisions should be based on monitoring and model results but that the presentation of these tradeoffs would not always make the decision any clearer for the Board members’ especially where the countervailing factors do not point in a clear direction. But there was a general sense among the PAG that with the DST, the issues and concerns of each of the interests and regions are being recognized and assessed.

It was agreed the DST needed to be flexible, in the sense that it can be readily updated with new data and new strategies, and that it should include a broad range of plausible future water supply scenarios, both high and low water. The risks of taking a given deviation action — or not taking it — should be equally apparent.

The PAG also offered suggestions about creating impact zones and crafting the descriptions of impacts that accompany each zone. They made numerous suggestions about ways to make the tool’s output more user-friendly, comprehensive and transparent.

The PAG engaged with the glam Committee on these matters and others despite an on-going conversation as to whether it is ever really possible for deviation decisions to balance interests and regions, some PAG members felt the answer was no. This was due to the complex nature of the system (Lake Ontario and the St. Lawrence River), the uncertainty inherent in weather projections, the varied ways in which impacts translate into costs borne by various interests (e.g. commercial navigation that serves a broader supply chain versus individual property owners versus ecosystem responses), and the limits inherent in water regulation compared to natural phenomena such as extreme wet and dry conditions.

As the GLAM Committee worked on the tool, PAG members pushed the GLAM Committee not to populate it just with numerical measures but to also incorporate what their report termed “a more nuanced and people-centered view of how various options may affect various parts of the system when deviation decisions are made.”

The PAG members said building inundation metrics did not capture shoreline impacts fully. They wanted the disruption of people’s lives and livelihoods taken into account, and metrics that were local as well as system-wide. The PAG emphasized that the DST should include impacts on local infrastructure — roads, docks, sewer systems, parks and the like — and find a way to use the DST to communicate subtler but significant impacts of extreme high water on shoreline residents such as the disruption of everyday life and the physical and emotional stress which PAG members recognized were difficult to measure.

PAG members argued that the public would have more confidence in the Board’s decisions if the public knew that local concerns and impacts were built into the tool. To show how this might be accomplished, the glam Committee created a prototype story map for a shoreline community in the Municipality of Brighton, Ontario, as previously discussed in Section 5.2. The prototype story map for Brighton received positive feedback from the PAG.

In 2021, the PAG spent most of their time focused on reviewing the DST, but they were also tasked with commenting on lessons learned and contributing their thoughts on a longer-term public engagement process.

In these discussions, PAG identified several benefits of the process. (see side box)

At the same time, the PAG encountered some difficulties, particularly related to the time commitment necessary to fully participate and the enormity of the challenge to understand the complex natural and human systems that interact in the watershed.

Members also struggled to fulfill the function of reaching out to their networks, partly because information developed by the GLAM Committee was in developmental stages and not ready for public distribution and partly because PAG members lacked the capacity for information sharing across such a large and diverse region. Some PAG members concluded that it is unrealistic to expect a relatively small group of volunteers to manage constituency engagement on subjects of significant controversy in the current atmosphere of polarized public discourse.

Looking ahead to any future public advisory bodies, PAG members said they would highly welcome the continuation of such a group to build on the social relationships and knowledge gained over the course of more than a year. However, time would need to be better managed, with sub-working groups and more concise and accessible educational materials available for communicating with the public. PAG members suggested that if the PAG continues into Phase 2, current members should be invited to stay with new members phased in. The PAG recommended that new committee members reflect greater diversity in socio-economic status, race, gender identity and ethnicity to provide a great range of experience and knowledge. The group provided some specific suggestions for protecting and potentially compensating the volunteers in a way that would allow them to retain their independence.

Finally, the PAG appreciated the stepped-up communications efforts and urged the IJC, Board and glam Committee to continue to improve its communications to the public and suggested more plain-language public communications and the establishment of public liaisons to act as two-way conduits for information in communities around the St. Lawrence River and Lake Ontario.

In a December 2020 communiqué, PAG offered recommendations on topics that were outside the immediate scope of their assigned duties but that they felt were imperative to work towards flood management. The PAG said the IJC should urge government agencies to create and fund robust emergency response plans that can be activated when extreme high water threatens, and to encourage government shoreline resilience planning, regulations and grants to help property owners, municipalities and other stakeholders.

From the GLAM Committee’s perspective, the PAG was a welcomed and important addition in the Phase 1 expedited review process. Despite the pandemic, the GLAM Committee was able to get acquainted with all of the PAG members and learn about their issues, seek their feedback and establish relationships, albeit virtual.

The GLAM Committee was very pleased with the level of engagement from pag members, and with their dedication and willingness to learn and hear each other’s points of view. The glam Committee also appreciated the thoughtful feedback received regarding the DST and guidance on how to address concerns. The glam Committee appreciated the coordination role of the Consensus Building Institute (CBI) who were expert facilitators and provided neutral moderation and a safe space for discussion and debate.

The GLAM Committee recognizes the burden placed on PAG members, both in terms of the time commitment necessary for a meaningful process and for trying to reach out to their respective networks. The committee agrees with the PAG’s assessment that more materials need to be available to help the PAG with this. This was difficult during the Phase 1 expedited review due to the tight timelines and involvement of the PAG in the real-time development of the DST which meant communication materials were not yet available. Nevertheless, the glam Committee deeply appreciates that PAG did reach out to their constituents at times and provided knowledgeable information via traditional media and social media which helped inform broader communities of the GLAM Committee process and helped correct misinformation.

The GLAM Committee sometimes found it difficult to maintain the pace required to keep the PAG informed and updated, but at the same time the semi-monthly schedule for meetings kept the process moving forward. The GLAM Committee did, at times, find it difficult to manage the high expectations of the PAG, especially when special requests were made for specific information and in regard to their assigned role as an advisory committee to the GLAM Committee and not the Board.

The GLAM Committee recognizes and appreciates the recommendations provided by the PAG for robust emergency response plans and resiliency planning and acknowledges the importance of these aspects in potentially reducing the risks of and improving the response to high water impacts. While largely outside the GLAM Committee’s scope, these recommendations have been forwarded to the IJC and the glam Committee will support the IJC as they consider how best to share these with responsible agencies.

Overall, the PAG provided great support to the GLAM Committee and was a critical voice in the development of the DST. The glam Committee is hopeful the IJC will renew the PAG for Phase 2 of the Expedited Review.

The expedited review of Plan 2014 is a good example of adaptive management in action. It is part of an iterative process to reduce uncertainty via system monitoring and modeling as well as learning through doing. This first Phase of the expedited review was geared towards filling some immediate data and information gaps needed to support International Lake Ontario – St. Lawrence River Board (Board) discretionary deviation decisions. This included gathering information from those directly impacted by the recent high-water conditions and undertaking technical studies to assess impacts across the different interests and regions. This first phase was focused in part on the flow limits in Plan 2014 and how these limits should be considered when the Board has authority to deviate from Plan 2014 flows. The following identifies the key findings from this Phase 1 effort based on a consolidation of the insights and observations identified in earlier sections of this report.

The Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee noted that little information has been gathered from Indigenous communities about the impacts of the recent high-water events. The GLAM Committee respects and recognizes the rights of Indigenous communities along the lake-river region and seeks to close this gap within the adaptive management effort including cultural perspectives and traditional practices. To achieve this, in 2021 the GLAM Committee began a process to hear more about perspectives of First Nations, Tribal Nations and the Métis Nation along the Lake Ontario and St. Lawrence River shoreline and/or with rights along the shoreline.

The GLAM Committee found the Public Advisory Group (PAG) to be a welcome and important addition in the Phase 1 expedited review process. The level of engagement from PAG members was excellent and members were dedicated and willing to learn and hear each other’s points of view. The GLAM Committee received thoughtful feedback regarding the Decision Support Tool (DST) and was provided guidance on how to address concerns that were raised.

The GLAM Committee sometimes found it difficult to maintain the pace required to keep the PAG informed and updated, but at the same time the frequent meetings kept the process on a steady track forward. The GLAM Committee at times, found it difficult to manage the high expectations of the PAG, especially when special requests were made for specific information and in regard to their assigned role as an advisory committee to the GLAM Committee and not the Board.

The GLAM Committee found that the third-party contractor was essential to engaging the PAG and provided expert facilitation and coordination, neutral moderation and a safe space for discussion and debate.

Both the PAG and GLAM Committee agreed that a similar group to the pag is needed moving into Phase 2, however, the PAG suggested that time would need to be better managed, with sub-working groups and more concise and accessible educational materials available for communicating with the public. The GLAM Committee and PAG also agreed that any changes to the current membership should be phased in.

The GLAM Committee and Board identified a number of factors that complicate deviation decisions, not the least of which is the uncertainty about what future water supplies will be. Reliable precipitation forecasts beyond a few days in the future are not yet available and yet a period of heavy rain or a drought can easily erase a deviation’s benefit. Climate change only exacerbates that uncertainty and increases the likelihood of even greater variability in water supplies in the future.

While uncertainty in forecasted conditions will remain an issue for the Board, the GLAM Committee will continue to seek out the best science and will work with its partners for ways to improve mid- to long-term forecasts. In the meantime, the GLAM Committee has developed some extreme water-supply scenarios that go beyond the historical record that the Board can take into consideration as it assesses risk of forecasted water supplies.

The Board wanted to know the certainty of the risks to interests and regions that are presented by extreme high water and how that risk would be shifted by their deviations. They identified some serious risks related to deviation decisions:

• During the spring freshet:
  Serious flooding on the lower St. Lawrence River can result from even a modest increase in outflow from Lake Ontario.
• During and after ice formation:
  Ecological damage in Lake St. Lawrence can result from abnormally high winter outflows, as can weakening of the river ice cover and resultant local flooding damage.
• During the navigation season:
  Shutdown of the Seaway with resulting damage to the shipping industry and its clients can result from deviations above the L Limit.

The GLAM Committee has characterized impacts across a number of interests, so the Board can get a better sense of who is being impacted by extremes, the severity of those impacts and whether their deviation strategy can improve conditions. This can help the Board assess the risk of taking, or not taking actions and the risk of transferring impacts from one interest or region to another.

I Limit

The I Limit requires that the level in Lake St. Lawrence be kept at 71.8 m (235.56 ft) or higher, as measured at Long Sault Dam. That value was specified in the limit because it was believed to be the minimum level needed to allow water-plant intakes to function properly. GLAM Committee research found this minimum may not be a limiting factor. Rather, new research conducted in support of the GLAM Committee found that low water levels on Lake St. Lawrence could lead to the stranding of aquatic creatures and concluded more research is required. The GLAM Committee also identified that another limiting factor may be loss of hydropower efficiency when operating at very low head caused by low levels on Lake St. Lawrence.

GLAM Committee research also found that it may be possible that the Board could deviate to increase winter outflow beyond the current I Limit when ice cover exists of 9,430 m3/s (333,000 cfs) under some circumstances and recommended further study.

L Limit

Broadly speaking, the L Limit provides a maximum outflow limit through the Moses-Saunders dam to maintain safe velocities and currents for commercial navigation to transit the Seaway. Another portion of the L Limit also ensures that levels of Lake St. Lawrence remain high enough for ships to transit through the channels.

Research and stakeholder engagement conducted by the GLAM Committee found that there may be some room for flexibility to the limit, especially in the summertime, if mitigation measures are in place. (There is less flexibility in the in the autumn, when currents are strong and the water level in the river was declining.) The GLAM Committee developed an independent, objective and non-proprietary assessment of the duration, timing and magnitude of the potential impacts to the commercial navigation sector of extremely high flow velocity scenarios. This research found that any temporary closure of the Seaway would have marked and measurable impacts and the most impactful would be a lengthy mid-season closure or an early end to the shipping season due to the volume of traffic and nature of cargo involved. In addition, the GLAM Committee also found there was no empirical basis for the two top outflows in Plan 2014’s L Limit and the assumptions in selecting 10,200 m3/s (360,000 cfs), and 10,700 m3/s (378,000 cfs) need revisiting.

As well, the GLAM Committee focused several studies on Lake St. Lawrence, which can be negatively impacted by efforts to reduce Lake Ontario flooding and is therefore critical to Board decision-making. Low-level thresholds on Lake St. Lawrence have been questioned and additional data gathering efforts for Lake St. Lawrence are required. The Board has expressed the importance of having all of this more detailed information to help them decide whether it is safe to exceed the flow limits, and the risk of taking, or not taking actions and the risk of transferring impacts from one interest or region to another.

F Limit

The F Limit’s fundamental purpose is to limit springtime high water and possible flooding, including flooding caused or exacerbated by the Ottawa River freshet, or spring runoff and to “balance” upstream and downstream impacts. During the high water events of 2017 and 2019 the Board found they lacked information to confidently develop a deviation strategy from the F Limit.

The GLAM Committee found several possible ways to adjust the F Limit or the Board’s reaction to the limit that can be further developed and evaluated within Phase 2. This included extending the target levels in increments and/or skipping the lower tiers of the target levels on Lake St. Louis. It also included varying the applicability of the targets with the timing of the freshet, tying those target levels to the inflow from Lake Erie or tying target levels to the inflow from the Ottawa River and adding a separate component to the F Limit to more directly consider Lake St. Pierre levels. All of these require further exploration and evaluation before being seriously considered for application by the Board as deviation options or as proposed modifications to the plan itself in Phase 2.

Building inundation, or flooding, is being used as an important impact metric that can be measured throughout the lake-river system. This contributed to the identification of broad-based regional impacts upstream and downstream and critical water level thresholds that can help inform F Limit deviation decisions.

Through various studies, the GLAM Committee was able to better define the scale and breadth of impacts to shoreline interests under different conditions and locations and assign critical water level thresholds (impact zones) to help inform the Board of the implications of deviation decisions across different geographies.

A Board decision will never be made without some degree of risk and uncertainty. What adaptive management tries to do is identify the risks and reduce the level of uncertainty as much as possible through on-going monitoring, modeling and verification. The GLAM Committee has tried within the DST to identify risks and uncertainties for the Board. For example, to isolate the added risk of complicating factors such as wind, waves, surge and incoming tributary flows, outcomes are presented both in terms of still water and in terms of the likelihood by season for major storm events and how that may or may not impact a deviation decision. The GLAM Committee cannot eliminate uncertainty, but it can continue to work toward improving science and data and filling data gaps in an effort to provide the best science available to the Board.

Board members have said they want a factual understanding of the trade-offs that accompany deviations — the benefit of changing the outflow to aid one interest or region versus the harm that outflow change might bring to another interest or region. Board members need insight into the uncertainties about the impacts that near-term and longer-term weather will have on the water levels and flows they are altering when they deviate.

The DST addresses these needs by making the Board’s work better-informed, more systematic and based on objective, vetted information.

While the DST cannot eliminate uncertainty about future water supply or provide complete assurance that a deviation will bring the result the Board intended, the tool still represents a valuable step forward because it allows the Board to act with much more knowledge than before and with a new ability to understand impacts among the many competing uses and interests. It is important that the Board trust the information within the DST, which means that updating and maintenance is critical to its use and effectiveness in information Board decisions.

As helpful as it should prove to be, the responsibility for the discretionary deviation decision remains with the six Board members consistent with the 2016 Supplementary Order of Approval and associated IJC Directives. The DST is not a decision-making tool.

Phase 1 of the expedited review was initiated due to concern over extremely high water levels. In spring 2021, the concern shifted to low water levels. This demonstrates the need for adaptive management as conditions are always changing. A key data gap that must be addressed is the lack of low-water metrics in the DST.

Additional ecosystem indicators, particularly for the upper St. Lawrence River and downstream areas that can be impacted by short-term Board deviations, should also be added to the DST. Further study of ecosystem impacts from low water levels during the winter on Lake St. Lawrence also is needed. Longer-term implications to ecosystems that may not be apparent in the short-term should be explored in Phase 2.

Shoreline erosion on the lower river needs to be added as a metric and was something identified in the Quebec municipal meetings due to the high sustained outflows in 2017 and 2019-2020. Shoreline erosion is also an important impact on Lake Ontario, though it may not be possible to differentiate erosion impacts on the lake shore that are associated with short-term deviation decisions and incremental water level differences of a few centimeters or inches.

While the Institute for Water Resources study that estimates the tons of cargo delayed and financial cost by navigational stoppages provides information the Board members have never had access to previously, it does not currently cover the Port of Montréal or downstream. Given the importance of this port to container ship traffic coming from the rest of the world, this is still a gap that needs to be filled. The GLAM Committee should continue to work with the Seaway corporations towards the development of a common metric and consider the development of a full Great Lakes/St. Lawrence River commercial navigation model.

Recreational boating and tourism were greatly affected by the high-water events of 2017 and 2019 and clearly are impacted by low water extremes. While some work was initiated in Phase 1, more study is needed to better understand the sensitivity of both direct and indirect impacts of deviation decisions on this sector. This will be given a greater emphasis in Phase 2 of the expedited review.

While targeted studies were completed for Lake St. Lawrence in Phase 1, given the immediate and sometimes significant affects deviation decisions can have directly on the forebay of the dam, a full and detailed investigation of all impacts categories (ecosystem, recreational boating and tourism, municipal water uses, First Nations, shoreline property, commercial navigation and hydropower infrastructure) should be completed for the entire Lake St. Lawrence region.

Some other locations within the system may require more site-specific study of indicators that are particularly relevant to their region such as tourism in the Thousand Islands area, traditional ecological knowledge and traditional ways of knowing in the Bay of Quinte and Lake St. Francis areas, and agriculture near Lake St. Pierre.

The PAG has strongly encouraged the glam Committee to include a wider range of metrics in the DST to reflect that personal nature of certain shoreline impacts for the Board. While preliminary efforts were made to incorporate that advice, the glam Committee will need to continually look at the suite of metrics in the DST and consider whether these metrics adequately reflect the range of impacts experienced by the different uses and interests. As well, the GLAM Committee will continue to work towards common and measurable metrics across all interests, including financial costs, to the degree possible.

As of July 2021, initial outreach had taken place to representatives of all First Nations, Tribal Nations and Métis Nations that directly reside along the Lake Ontario and St. Lawrence River shoreline along with those Indigenous Nations with rights related to the shoreline (as listed in Section 2.8) and a number of individual virtual meeting sessions had been arranged. The GLAM Committee continued to follow up with various First Nations, Tribal Nations and Métis Nations throughout the late summer and fall of 2021 as a starting point from which to begin a dialogue and build relationships to improve learning and the integration of Indigenous perspectives and knowledge and it is expected this will continue through Phase 2. The GLAM Committee is committed to exploring opportunities to include traditional ecological knowledge, cultural perspectives, and traditional ways of knowing into the plan evaluation effort and on-going adaptive management process for informing both the on-going review of Plan 2014 and efforts on the upper Great Lakes related to Plan 2012 for the outflows from Lake Superior.

The GLAM Committee has found the PAG to be dedicated contributors to the Phase 1 process and have appreciated the thoughtful feedback received. The GLAM Committee wholly supports and recommends the continued involvement of the PAG in Phase 2. The Committee will consider the recommendations for on-going public engagement from the pag and work with the IJC on next steps. This includes the PAGs recommendations that a new committee reflect greater diversity in socio-economic status, race, gender identify and ethnicity to provide a greater range of experience and knowledge. The PAG urged the IJC, Board and GLAM Committee to continue to improve its communications to the public and recommended the establishment of public liaisons to act as two-way conduits for information in communities around the St. Lawrence River and Lake Ontario.

The GLAM Committee further recommends that an independent facilitator continue to be engaged to help ensure an effective and efficient public engagement process.

Information from various sources was used by the GLAM Committee to develop the DST to assist the Board in assessing impacts and tradeoffs associated with high water levels throughout the Lake Ontario and St. Lawrence River system. While the Board views the information provided by the tool as a considerable improvement, it is also recognized that the tool is only effective if the Board has full confidence in the information it provides. It is therefore critically important for the DST to be continually updated and improved over time as an on-going component of adaptive management.

The DST currently is a Microsoft Excel-based tool. The GLAM Committee should explore alternative platforms in consideration of the long-term use, accessibility and performance of the DST. A strategy for the on-going maintenance and updating of the DST should be developed and implemented including identified resources and agency support within the GLAM Committee and Board.

The DST has been identified as having potential benefits both for communicating with the public and for informing practitioners interested in water level/resiliency issues. The GLAM Committee should continue discussions with the Board of potential public and practitioner uses of some version of the tool. At the very least the Board and GLAM Committee should explore opportunities for using the outcomes from the DST as a means of communicating with the public on how and why a deviation decision was made.

Even with the additional information provided by the DST, deviation decisions will not be easy. There is good evidence from hydroclimate science that higher levels are possible upstream and downstream than experienced in 2017 and 2019-2020. While Phase 1 was focused on high water extremes, it is recognized — especially given the experience in the spring and summer of 2021 — that low-water extremes also must be considered and will be added to the DST in the future. This again is an example of why adaptive management is needed to address a system that is always changing.

Given all of this variability and the dynamic nature of the system and that new information will continue to be included into the DST, it is highly recommended by the GLAM Committee that the Board continue to practice with the DST so members become accustomed to using the tool in an operational mode. It is further recommended that the Board use the DST to explore different extreme scenarios and to learn how Board members can use the tool to assess risk and uncertainty of various deviation options prior to an extreme event (high or low). While the Board members themselves will likely not be the ones manipulating the tool, that support will come from GLAM Committee and Board staff, it is important for the Board and its IAG members to have a solid understanding of the tool itself and the data that drives it. In doing so, the Board can be better prepared to address extreme conditions when they do occur, and they can work with the GLAM Committee to identify improvements that could be made to improve the DST.

Adaptive management tries to identify the risks and reduce the level of uncertainty as much as possible through on-going monitoring, modeling and verification and this must continue to inform the Board’s deviation decision-making. The GLAM Committee has an on-going mandate to review and assess the performance of the regulation plans and this requires continual data gathering and verification. The GLAM Committee should prioritize the data gaps identified in the findings above and systematically address these gaps. The GLAM Committee should be looking to build common metrics where possible and should be examining and making use of new and evolving technologies such as machine learning for gathering data more efficiently.

Data sharing procedures and protocols, and where necessary data sharing memorandums of understanding, should be established with potential partner agencies to allow accessibility to data, information and tools generated for the GLAM Committee.

Phase 2 will include analysis of possible modifications to Plan 2014’s rules, limits and “trigger levels”. A study done in Phase 1 by the GLAM Committee identified a number of possible changes to the I, J, L and F limits that will be explored in Phase 2 (see Section 3.3), and others may be added.

The next phase will build upon the data and modeling tools developed during Phase 1 (see Table 10) and will include acquisition and analysis of data about impacts of extreme high and low water, building upon the data gaps noted above. Phase 2 analyses will directly include Indigenous Nations and will have a greater emphasis on ecosystem impacts on Lake Ontario and the St. Lawrence River than were included in Phase 1. This is because some of these impacts are only measurable after a number of years and Phase 2 will consider a long-term time horizon.

Analyses will be conducted under a full range of possible future water supply conditions, including climate change projections. It is important to note, that while Phase 1 focused primarily on providing information to inform Board deviation decisions and did not recommend specific options for the Board, Phase 2 will take a different and more fulsome approach to evaluating alternatives to Plan 2014 rules, limits and “trigger levels” for leading to improved outcomes and will include the evaluation of options to allow for the ranking of alternatives.