Lake Champlain-Richelieu River Study Board Releases Final Report


After five years of US-Canadian collaboration and research, the International Lake Champlain-Richelieu River Study Board (the Board) submitted its final report and recommendations to the International Joint Commission. The Report investigated the causes, impacts, risks and potential solutions to flooding in the Lake Champlain-Richelieu River basin shared between Quebec, Vermont and New York.

The report contains several recommendations and addresses the following themes:

  1. Reduction of water levels via structural mitigation measures
  2. Effects on impeding flows during floods of existing and additional wetlands in the basin
  3. Enhancements to flood forecasting and flood response in the basin
  4. Floodplain management best practices and lessons learned in other watersheds

The Board’s main recommendations include:

  • that selective excavation of the riverbed near Saint-Jean-sur-Richelieu, Quebec combined with the construction of a submerged weir would reduce high water levels during floods and would have the added benefit of raising water levels on Lake Champlain during dry years. A moderate diversion of high flows through the Chambly Canal could also be considered for additional flood-reduction benefits.
  • the preservation of existing wetland areas which can minimize water levels during floods while also stabilizing water levels during droughts in the basin.
  • the governments are encouraged to operationalize the improved modeling and forecasting tools and coherent risk assessment systems and support/maintain them after the Study. The agencies responsible for flood forecasting in the basin continue collaboration and make available forecasting data so that forecasts on both sides of the border are of the highest possible quality and are accompanied by a concerted and consistent cross-border interpretation
  • improving floodplain mapping for the use of emergency managers and enhancing communication campaigns around flood risk in the basin. The Board also recommended that jurisdictions in the basin reviews their floodplain management policies through the lens of making these areas more resilient for possible future floods.

The Board recognizes that the occurrence of flooding in the basin is inevitable; however, structural and non-structural approaches can be used to minimize the damage done by these floods to communities and stakeholders. The Board also noted the importance of building more resilient communities in the Lake Champlain-Richelieu River basin.

The International Joint Commission will review the Board’s report and is holding public hearings and seeking public comments on this report from August 19 to September 30. The IJC will consider all comments before submitting its final recommendations to both the Canadian and U.S. governments by the end of 2022.


“I want to sincerely thank the Board and all collaborators for their dedication and outstanding work on this report. The level of engagement with the public, interest groups and Indigenous communities in the basin was unparalleled. Meaningful engagement enabled the Board to consider a wide array of perspectives and ultimately make informed decisions that would benefit residents in Canada and the United States. The investments in this unique study have produced models and tools that will be of use in other watersheds in both countries.”

Pierre Béland, Commissioner and Canadian Chair

“This report is critical to help mitigate future damages and flooding in this shared basin. An immense amount of work went into this report, and I want to extend my deepest gratitude to the Board and all partners who contributed to it. The Commission looks forward to reviewing the report and making recommendations to both governments.” 

Robert Sisson, Commissioner and Acting United States Chair

Quick Facts

  • The International Joint Commission (IJC) established the International Lake Champlain-Richelieu River Study Board in 2016 to undertake a study of the causes, impacts, risks and potential solutions to flooding in the basin as per the Reference received from the U.S. and Canadian governments.
  • Throughout the study, the Board engaged and collaborated with various groups and partners in the basin, such as the general public, emergency managers, elected officials, Indigenous communities and the Board’s Public Advisory Group. The Board conducted dozens of meetings, public consultations (virtual and in-person), technical webinars and special outreach sessions over its 5-year study.
  • IJC is seeking public comments on the final study report from August 19 to September 30. To participate, visit the IJC’s consultation page.

Associated Links


Christina Chiasson Canadian Section (613) 293-1031  

Kevin Bunch US Section (202) 632-2014