IJC reports on flood forecasting with flood inundation maps for Lake Champlain and Richelieu River


The International Joint Commission (IJC) today releases its report A real-time flood forecasting and flood inundation mapping system for the Lake Champlain-Richelieu River watershed.

The IJC’s report builds on the work of the International Lake Champlain-Richelieu River Technical Working Group (TWG), technical experts appointed by the IJC from the United States, Canada, Quebec, Vermont, and New York to respond to a request from the federal governments to address two issues associated with the flooding that took place in Lake Champlain-Richelieu River watershed in 2011.

"The Commission strongly endorses the Working Group’s report and its recommendations and recommends that the Governments of Canada and the United States focus on completing an operational, real-time flood forecasting and flood inundation mapping system for the entire Lake Champlain-Richelieu River watershed," said Commissioner Benoit Bouchard. "This is consistent with current efforts by governments to have the most current and credible scientific information in hand to mitigate flood risks and to properly plan emergency responses."

The inundation maps show flooding potential under different flood scenarios and are not designed for regulatory purposes. A preview of these maps is available on the IJC web site at: http://arcg.is/1MhXui2.              

The IJC endorses the TWG observation that enhanced coordination among agencies involved in real-time forecasts is necessary to support the development and maintenance of forecast models and quality-controlled joint water level predictions. The Commission endorses the TWG recommendation that a binational coordination body be mandated and funded to consolidate and synthesize flood forecasting work undertaken domestically into a single binational flood forecast. This body would also be charged with developing and disseminating consistent messaging to emergency responders and the public.  

In July 2013, the IJC recommended a comprehensive Plan of Study "The Identification of Measures to Mitigate Flooding and the Impacts of Flooding of Lake Champlain and Richelieu River."

The governments of the United States and Canada subsequently asked the IJC to address two issues associated with this broader Plan of Study, namely:

  1. closing the gaps in the data needed for a future real-time flood forecasting and inundation mapping system, and
  2. the creation of static flood inundation map products. 

Consequently, the new IJC report does not evaluate potential flood mitigation measures as this was outside the terms of reference provided by governments.

The Commission reiterates its strong recommendation that governments implement the full scope of the 2013 Plan of Study (PoS) to evaluate past impacts, flood plain management practices and adaptation strategies, and to assess soft (i.e., low impact and cost) to moderate flood mitigation measures and their impacts.

Commissioner Dereth Glance noted, "The IJC is proud to display the state-of-the-art static flood-inundation maps online for use by local governments and the general public.   As future mitigation measures are considered, the Commission recommends that the full scope of the 2013 Plan of Study move forward, and that static flood inundation maps are completed for communities within the entire binational Lake Champlain-Richelieu River basin."

The IJC hosted workshops in Burlington, Vermont and Saint-Jean-sur-Richelieu, Quebec with  local experts including emergency responders, community planners, municipalities, and public security organizations to review the draft report Towards a real-time flood forecasting and flood inundation mapping system for the Lake Champlain-Richelieu River watershed.  The public was invited to comment from late November to early December. A strong expression of interest was shown for an operational real-time flood forecasting and mapping system for the Lake Champlain-Richelieu River Basin. Public comments received can be reviewed at: http://ijc.org/en_/Lake_Champlain-Richelieu_Flood_Forecasting_and_Mapping




 Nick Heisler    (English)





 Sarah Lobrichon (French)      





 Frank Bevacqua