The 2011 Lake Champlain and Richelieu River floods were a series of water level increases that began at the end of April 2011 and caused a subsequent overflow of the Richelieu River in Canada and Lake Champlain in the United States.^[1] The flooding occurred due to record snowfall in the area followed by its snowmelt and in combination with intense spring rains.^[2] Lake Champlain stayed at flood stage for 67 days from April to June, and on May 10, 2011, the lake broke its previous flood level set in 1869 by reaching 102.8 ft. at Rouses Point, New York.^[3][2][4] The floods affected about 3,000 homes in Montérégie^[5][6] and caused an estimated six million U.S. dollars of damage in seven counties in the northern area of Vermont.^[7][8] The damage was so bad that a state of emergency was declared by Vermont on May 5, 2011.^[9] Similar damage was reported in New York State.

You can help expand this article with text translated from the corresponding article in French. (June 2011) Click [show] for important translation instructions. View a machine-translated version of the French article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing French Wikipedia article at [[:fr:Inondations du bassin du lac Champlain et de la rivière Richelieu de 2011]]; see its history for attribution. You may also add the template {{Translated|fr|Inondations du bassin du lac Champlain et de la rivière Richelieu de 2011}} to the talk page. For more guidance, see Wikipedia:Translation.

Quick Facts Date, Location ...

2011 Lake Champlain and Richelieu River floods

Lake Champlain and the Richelieu River basin
Date	April 2011 – End June
Location	New York Quebec (Montérégie) Vermont
Deaths	None

Close

In Quebec, the major cities affected by the flooding were Venise-en-Quebec, Noyan, Saint-Jean-sur-Richelieu, Henryville, Saint-Paul-de-l'Île-aux-Noix, and Sainte-Anne-de-Sabrevois.^[10] Citizens of Quebec were supplied with safe drinking water by the government due to the prolonged period of time in which the city's water supplies were likely contaminated.^[2] On May 5, the Canadian Forces were requested to help evacuate residents and build dikes to try to protect areas at risk.

Operation Lotus was the name of the military operation that assisted citizens in the Montérégie area in response to a formal request for assistance from the province of Quebec as a result of this natural disaster.^[11][12] The Canadian Forces worked to limit the damage caused by the worst floods to occur in the valley of the Richelieu River and on Lake Champlain over the previous 150 years.^[13] Over 650 Canadian soldiers and sailors participated at one time or another in Operation Lotus until it ended on June 17.^[14]