Moses-Saunders Dam

Board Planning to Assist with Lake St. Lawrence Boat Haul-out


Due to the declining Lake Ontario level combined with extraordinarily high outflows still being released through Moses-Saunders Dam, the forebay upstream of the dam has seen a significant sustained drop in water levels, making it extremely challenging to haul-out boats that would normally be removed at this time of year under more-normal flow conditions.  To assist these efforts, the Board will temporarily reduce outflows and increase water levels on Lake St. Lawrence by approximately 65 cm (25.6 in) which will allow marinas and shoreline property owners with docks a one-time opportunity to access their boats to haul-out for the season.

A 1,000 m3/s (35,300 cubic feet per second) outflow reduction is scheduled for all day on October 12 and 13 for a 48 hour period. This is equivalent to 1 cm (0.4 in) of water that would otherwise be released from Lake Ontario during this time, and this additional amount will be removed over the fall months as conditions allow to ensure the net impact on Lake Ontario water levels will be zero. 

The Board carefully considered the full range of impacts of this operation, including the significant impact that high 2019 Lake Ontario and St. Lawrence River water levels have had, and in some cases continue to have, on people who live and work along the shoreline.  The Board also considered the relief it would provide to the recreational boaters on Lake St. Lawrence, following a third consecutive year that low levels here have presented challenges to this other area of the Lake Ontario – St. Lawrence River system.  There are approximately 700 marina and boat club slips around Lake St. Lawrence and hundreds of private docks that are impacted. Without raising water levels here, many boats would be left on the bed of Lake St. Lawrence and vulnerable to significant damage from winter conditions.

It is critically important that the memories of these high water impacts are documented and summarized so that as time goes, these will not be forgotten. To support such a summary, the IJC’s Great Lakes – St. Lawrence River Adaptive Management (GLAM) Committee, a subcommittee supporting the ILOSLRB, is seeking first-hand observations and experiences from all who would volunteer to tell their story related to high water impacts in 2019.

A questionnaire has been developed that allows impacted shoreline property owners to report directly on their experiences in 2019. The questionnaire includes opportunities to describe the types and extent of their high water impacts, as well as upload photos to illustrate those impacts.  Responses will be summarized by the GLAM Committee as part of its reporting to the ILOSLRB and the IJC and will also be used to improve models that are used to assess potential impacts under a range of water level conditions.  Further information, including a link to the questionnaire itself, is available on the GLAM Committee website (  Property owners are encouraged to complete the questionnaire as soon as the extent of their high water impacts are available.

As has been necessary in recent weeks, outflows will continue to be reduced weekly to prevent dangerous river currents. Velocities increase because, as the lake level decreases, so does the water level within the upper part of the St. Lawrence River, reducing the amount of space for water being released to move through. Imagine the channel as a trough and as the water level lowers, the depth of water in the trough decreases. For the same flow (e.g., 10,400 m3/s) to go through that trough, the water has to move faster.  Given the current conditions, velocities are higher than normal throughout the river and they are already causing unsafe cross-currents and erosion and are impacting many interests in the St. Lawrence River. Sustaining or increasing velocities would cause conditions to become much worse.

Information on hydrologic conditions, water levels and outflows, including graphics and photos, are available on the Board’s website and posted to the Board’s Facebook page at (English), and more detailed information is available on its website at


Rob Caldwell: (613) 938-5864;

Andrew Kornacki: (716) 879-4349, (716) 352-8669;


The International Lake Ontario – St. Lawrence River Board specifies the outflows from Lake Ontario, according to Plan 2014 as required in the 2016 Supplementary Order from the International Joint Commission. This plan was agreed to by the United States and Canada in December 2016 in an effort to improve environmental performance while maintaining most of the benefits provided to other interests by the previous Plan 1958-D, which was in use since 1963. In determining outflows, the Board, in conjunction with its staff, pays close attention to water levels in the Lake Ontario-St. Lawrence River system and on the Great Lakes upstream, and to the effects on stakeholders within the basin.

Water levels vary from year-to-year and throughout the year depending on weather and water supply conditions. Such variations benefit coastal wetlands and are critical to a healthy lake environment, but may at times and depending on individual circumstances increase the vulnerability of shoreline structures and reduce opportunities for recreational boating activities.  The Board urges everyone to be prepared to live within the full range of levels that have occurred in the past and of those that may occur in the future.  Based on historical observations and projected future conditions, at a minimum, Lake Ontario water levels are expected to range from a high of 75.92 m (249.1 ft.) to a low of 73.56 m (241.3 ft.) at infrequent intervals. However, it is also recognized that future climate conditions are uncertain, and more extreme water levels may be reached and these extremes may occur more often.  Levels on the St. Lawrence River tend to vary more widely than on Lake Ontario.  Also, these levels do not include the varying local effects of strong winds and wave action that significantly increase or decrease local water levels on both the lake and river, with temporary changes of over half a meter (two feet) possible in some locations.

For more information, please see the Board’s website ( and Facebook page ( receive a weekly email about water levels and flows in the Lake Ontario–St. Lawrence River system, please send a blank e-mail message to with the word ’subscribe’ in the title and body of your message.