2.1 What does the Board regulate?
The Board regulates Lake Superior outflows, ensuring that they meet the requirements of the International Joint Commission's (IJC) Orders of Approval. The Board operates under the current regulation plan (Plan 2012) and conducts special studies as requested by the IJC. Plan 2012 reflects the natural rhythms of the upper Great Lakes. Though the Board regulates outflows, the system is primarily influenced by natural processes, such as inflow from precipitation and runoff, evaporation losses, weather patterns, and wind (see Section 3: Influences on Water Levels and Flows).
The Board reviews the hydrologic and water level conditions regularly and generally attempts to follow the outflows prescribed by the regulation plan. In most cases, deviations from the Plan-prescribed outflows are authorized only if certain water level or flow conditions are encountered and only up to specific limits.
On the basis of the regulation plan, the Board’s Regulation Representatives determine a monthly mean outflow each month and direct the hydropower entities to adjust their releases to the required rate, effective on a date near the start of each month. If required, the Board will also direct that the gate setting of the Compensating Works be adjusted to ensure the total required Lake Superior outflow is met.
Plan 2012 is the current regulation plan for Lake Superior. The principle objective of this plan is to regulate the outflow from Lake Superior in consideration of conditions and interests both upstream on Lake Superior, and downstream on the St. Marys River and Lake Michigan-Huron. The plan provides modest benefits to commercial navigation, hydropower, and coastal zone interests, and maintains much of the natural variability in lake levels that is important for ecosystem health, while remaining consistent with the capacities of the current discharge structures at Sault Ste. Marie, and with winter flow restrictions employed to reduce the risk of ice jams. Plan 2012 resulted from a review and update of Plan 1977-A, the previous regulation plan, and has been in use since January 2015.
There are two Regulation Representatives that carry out the day-to-day regulation activities of the Board. The Board’s U.S. Regulation Representative is the District Commander at the U.S. Army Corps of Engineers’ Detroit District office in Detroit, Michigan, and its Canadian Regulation Representative is a Senior Water Resources Engineer at the Great Lakes - St. Lawrence Regulation Office of Environment Canada in Cornwall, Ontario. Regulation Representatives have strong technical backgrounds and are typically professional engineers. They are supported by a team of water management engineers and technical experts. Among other duties, the Regulation Representatives:
- Perform the monthly regulation computations according to the regulation plan,
- Advise the Board on actual and potential technical issues,
- Ensure that regulation operations follow the Board’s intended strategy,
- Act on behalf of the Board in emergency situations where immediate decisions to change flows may be needed,
- Collect and evaluate water level, flow, ice, and hydro-meteorological data related to outflow regulation,
- Act as the Board’s technical liaison and monitor and coordinate flow regulation activities with hydropower and navigation entities,
- Provide expert technical advice and data (e.g., water level and outflow data and forecasts, datasets, statistics, etc.) to stakeholders, the public and media,
- Undertake studies and analyses as necessary to improve and facilitate regulatory operations and decisions, and
- Ensure the accuracy of reported water level and flow data relevant to regulatory operations.
The 2014 Orders of Approval provide four criteria for setting flows through the project. They address:
- both upper and lower target levels for water levels on Lake Superior,
- regulated outflows from Lake Superior and their effect on the maximum level of Soo Harbor,
- restricting the frequency of low levels of Lake Superior, and
- ice management in the St. Marys River.
The full text of the 2014 Orders of Approval, including the four criteria, is available online.
The current regulation plan (Plan 2012) determines outflows that meet the criteria established under the Orders of Approval. The IJC has also issued supplementary directives to the Board, including one that outlines conditions and requirements that the Board must adhere to if it were to release flows that deviate from those specified by the Plan, and another that outlines provisions pertaining to hydropower peaking and ponding operations.
2.7 What authority does the Board have to consider individual interests when setting Lake Superior outflows?
In 2015, the IJC issued a directive to the Board pertaining to deviations from the regulation plan. As noted in the Deviation Directive, in most instances it will be important to release flows as determined by Plan 2012 in order to realize its expected benefits to the various interest groups affected by water levels. Therefore, it is anticipated that deviations from Plan 2012 will be infrequent, and that outflows will be set as is prescribed by Plan 2012 in the majority of cases. However, the Board may make a recommendation to depart temporarily from the regulation plan flow when such deviations would provide relief from adverse impacts to any interest without appreciable adverse effects to any of the other interests. At various times, deviations may be used to assist hydropower, navigation, shoreline property owners, recreational boaters, the ecosystem, and other interests.
The Deviation Directive allows the Board to conduct minor discretionary deviations from Plan 2012 outflows without prior approval from the IJC. The net effect of these minor deviations on either Lake Superior or Lake Michigan-Huron levels is limited to no more than about +/- 0.5 cm from that which would have occurred had the releases prescribed by the Lake Superior regulation plan been followed. Major deviations that result in water level impacts in excess of +/- 0.5 cm are to be avoided when possible to minimize adverse effects on interests, but may be deemed prudent during extreme conditions when water supplies exceed those of the past, or when conditions exceed or conflict with the maximum or minimum physical capacities and requirements that were assumed during the development of Plan 2012. As the effects of such major deviations would be greater than the limits under which minor discretionary deviations are allowed, they require the IJC’s advance approval.
2.8 What actions do the IJC and Board take to react to low water supplies and avert extreme low water levels in the upper Great Lakes?
The criteria and regulation plan aim to maintain Lake Superior levels above 182.76 m (599.61 ft) even under very dry conditions. The regulation plan was designed to reduce outflows as conditions become drier, within defined limits. When conditions require, the Board may deviate from the plan in order to reduce outflows even further (e.g., to reduce flood risks) or to increase outflows (e.g., to release water to meet a specific short-term need).
2.9 Can water be stored on Lake Superior to provide a buffer against low water conditions downstream?
Yes, technically speaking. In so doing, however, relevant interests need to be considered and balanced. For example, water levels in Lake Michigan-Huron need to be considered along with other interests. In such a system, no one interest can be perfectly satisfied all the time to the detriment of other interests.
2.10 What adaptive measures should water users and property owners be taking above and below the control structures to protect against adverse impacts, and will the Board be taking actions to encourage such measures to be implemented?
The Board always encourages water users and property owners to plan for the full range of water levels that have been experienced historically. Recommending specific adaptive measures is beyond the purview of the Board, but information on this topic is readily available, including in some of the agency publications provided on the Reports page of the IJC website.