{"id":688772,"date":"2026-05-23T15:15:12","date_gmt":"2026-05-23T15:15:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/688772\/"},"modified":"2026-05-23T15:15:12","modified_gmt":"2026-05-23T15:15:12","slug":"water-levels-update-for-lake-ontario","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/688772\/","title":{"rendered":"Water levels update for Lake Ontario"},"content":{"rendered":"<p>The International Lake Ontario-St. Lawrence River Board (the board) continues to monitor conditions in Lake Ontario and the St. Lawrence River:<\/p>\n<p>Continued rainfall and runoff may result in flooding of vulnerable areas along the Lake Ontario shoreline as well as downstream along the St. Lawrence River, including the Montreal archipelago and Lake St. Pierre.<br \/>\nWater levels of Lake Ontario and the St. Lawrence River (Lake Ontario: 75.37 metres or 247.28 feet; Pointe-Claire: 21.91 metres or 71.88 feet) remain above long-term (1960-2025) average but well below the record high for this week, i.e., 75.85 meters or 248.85 feet, that occurred in 2017.<br \/>\nLake Ontario outflows will continue to be set in accordance with the rules of Regulation Plan 2014. The board may deviate from these prescribed flows if <a title=\"https:\/\/ijc.org\/en\/loslrb\/who\/directives\/deviations\" href=\"https:\/\/ijc.org\/en\/loslrb\/who\/directives\/deviations\" target=\"_blank\" rel=\"noopener noreferrer nofollow\" data-auth=\"NotApplicable\" data-linkindex=\"0\">criterion H14<\/a> Lake Ontario levels are met, and the board determines that deviations are warranted. Criterion H14 trigger water levels vary through the year. The current upper H14 trigger level is 75.60 metres (248.00 feet).<br \/>\nIf weather conditions are near average, Lake Ontario is expected to reach a <a title=\"https:\/\/ijc.org\/en\/loslrb\/watershed\/forecasts\" href=\"https:\/\/ijc.org\/en\/loslrb\/watershed\/forecasts\" target=\"_blank\" rel=\"noopener noreferrer nofollow\" data-auth=\"NotApplicable\" data-linkindex=\"1\">seasonal peak<\/a> of approximately 75.40 metres (247.37 feet) in May or June. However, higher water levels are possible if weather conditions are much wetter than average. Long-term water levels are difficult to predict, much like weather forecasts.<br \/>\nStrong winds, when coupled with even moderately-high water levels, can result in localized flooding of vulnerable areas along the Lake Ontario shoreline as well as downstream along the St. Lawrence River, including Lake St. Louis and Lake St. Pierre.<\/p>\n<p>\u00a0There has been persistent precipitation throughout the Lake Ontario and St. Lawrence River basin this spring. The Ottawa River, which meets the St. Lawrence River at Montreal, discharged around 7,740 cubic metres per second (m3\/s) or 273,300 cubic feet per second (ft3\/s) into the lower St. Lawrence River on April 22. This is approximately three times the amount of water that flowed over Niagara Falls (2,600 m3\/s or 91,800 ft3\/s) that same day. To add to that, Rochester, NY, recorded its wettest March and April in 153 years. <\/p>\n<p>Due to this persistent precipitation and high Ottawa River flows, frequent Lake Ontario outflow adjustments were made between April 16 and May 6 in accordance with the <a title=\"https:\/\/ijc.org\/en\/loslrb\/watershed\/faq\/4#4-8-2\" href=\"https:\/\/ijc.org\/en\/loslrb\/watershed\/faq\/4#4-8-2\" target=\"_blank\" rel=\"noopener noreferrer nofollow\" data-auth=\"NotApplicable\" data-linkindex=\"2\">F limit<\/a> which aims to balance risks and impacts associated with flooding both upstream and downstream of the Moses-Saunders Power Dam. [The F limit sets maximum outflows from Lake Ontario based on the level of Lake St. Louis (<a title=\"https:\/\/wateroffice.ec.gc.ca\/report\/real_time_e.html?stn=02OA039\" href=\"https:\/\/wateroffice.ec.gc.ca\/report\/real_time_e.html?stn=02OA039\" target=\"_blank\" rel=\"noopener noreferrer nofollow\" data-auth=\"NotApplicable\" data-linkindex=\"3\">measured at Pointe Claire<\/a>) to limit downstream flooding in consideration of Lake Ontario levels.] Since then, Ottawa River outflows have declined, enabling the Lake Ontario outflow to increase. As of May 7, the Lake Ontario outflow has been set in accordance with the Plan 2014 applicable Rule Curve flow and is no longer restricted by the F limit.<\/p>\n<p>While the board regulates outflows from Lake Ontario, regulation cannot eliminate the recurrence or negative effects of extremely wet or dry water supplies on water levels. These water supplies and processes are uncontrolled; most of the water coming into Lake Ontario comes from Lake Erie, while remaining water comes from precipitation, runoff and evaporation, in the basin.<\/p>\n<p>\u00a0Community members should continue to monitor conditions in their local area. Emergency planning and response are typically provided through local municipalities.<\/p>\n<p>\u00a0For more information:<\/p>\n<p>\u00a0The International Lake Ontario-St. Lawrence River Board ensures that outflows from Lake Ontario meet the requirements of the International Joint Commission\u2019s Orders of Approval. Under any regulation plan, the ability to regulate the outflow from Lake Ontario does not mean that full control of lake levels is possible. This is because the major factors affecting water supply to the Great Lakes, precipitation, evaporation, and runoff cannot be controlled, and are difficult to accurately predict.<\/p>\n","protected":false},"excerpt":{"rendered":"The International Lake Ontario-St. Lawrence River Board (the board) continues to monitor conditions in Lake Ontario and the&hellip;\n","protected":false},"author":2,"featured_media":688773,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[3735,3736,49,48,295,44,3733,3731,3734,3729,3730,3737,66,3732],"class_list":["post-688772","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-bancroft","tag-brighton","tag-ca","tag-canada","tag-environment","tag-news","tag-pec","tag-picton","tag-prince-edward-county","tag-quinte","tag-quinte-news","tag-quinte-west","tag-science","tag-trenton"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/688772","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=688772"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/688772\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/688773"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=688772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=688772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=688772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}