IJC Lake Champlain and the Richelieu River Project Active

In July 2013, the International Joint Commission (IJC) submitted the LCRR Plan of Study (PoS) to the Governments of Canada and the United States. The 2013 PoS outlined the work required in the LCRR basin in order to explore potential floodplain management solutions and to provide a range of structural and non-structural flood prevention and mitigation measures. In 2015, the IJC LCRR Technical Work Group completed some initial tasks identified in the PoS. In 2016 the U.S. and Canadian governments decided to pursue Option B as described in the PoS; this decision lead to a reference to the IJC to conduct Option B activities, and for IJC to create the International LCRR Study Board to oversee and conduct studies and work related to Option B. This draft Work Plan describes these activities, the time line of these activities and their costs.

LCRR Study Board was created in 2017 and is comprised of an equal number of members from the U.S. and Canada. In addition, a full study governance structure has been developed to include study co-chairs, technical work advisory groups, public outreach and communications groups, study co-managers, and information technology and management support.The Study Board will be responsible for overseeing and managing the study and ensuring that the government mandates are met. The work include seven objectives:

• Evaluating the causes and impacts of past floods, especially the event of 2011.
• Assessing the possibilities offered by the floodplain best management practices.
• Evaluating possible adaptation strategies to the expected future variability in the water supplies.
• Developing and making recommendations for implementing, as appropriate, an operational, real-time flood forecasting and flood inundation mapping system for the Lake Champlain-Richelieu River watershed.
• Conducting an in-depth study of current social and political perception on structural and other mitigation measures to support and confirm the desirability of potential structural mitigation solutions.
• Performing a quantitative and qualitative assessment of potential flood management and mitigation measures (non-structural and/or moderate structural works) and their impacts on important resources of the system: the wetland and fauna, recreational, domestic, industrial and municipal uses of water, shoreline and floodplain built environment and agriculture.
• Developing resource response models that include basic indicators for water resources response to water levels fluctuations, with special attention on the data inventory and identification of thresholds. Climatic projections, wind wave and ice models, additional new data for the evolution of watershed physiographic characteristics over time and a complete digital terrain model will be produced to allow the planning, evaluation and ranking of potential flood mitigation solutions, using a shared-vision approach.

The seven major objectives of the study require a multi-disciplinary and interactive strategy to complete the goals of this study. The multi-disciplinary, interactive strategy is emphasized in the structure and governance developed for the study. A unique feature of this study is the emphasis placed on understanding social, political and economic drivers associated with flood mitigation and forecasting.

The development of new hydraulic models for forecasting LC and RR water levels is an important product proposed in the study. These new models will be 2-dimensional (2D) in nature and will be integrated so they perform in a seamless manner. The option of the U.S. using a 3D model to support the study is being reviewed by experts working on this Study. The models will used to forecast future lake and river water levels, evaluate potential flood management and mitigation measures, and evaluate how varying water levels influence important response indicators. These indicators could include critical aquatic habitat or species, recreational uses, water intake and discharge points, economic values, and social perceptions.

A broad social, political and economic analysis of flood management will be evaluated in this study.Studies on social, political and economic values – whether actual or perceived – will be conducted so that final options and solutions will receive the broadest public support for implementation. Frequent interactions with various sectors of society and feedback and input from them will be gathered as part of the social, political and economic analysis.

An analysis of various non-structural and structural flood mitigation measures will be undertaken in the study. A review of existing practices, mitigation methods and structures will be performed. This review will focus both locally in the LCRR basin as well as elsewhere by consulting the existing literature.In addition, how these various measures would be effective in managing water levels will be tested with the new hydraulic and hydrologic models being developed, so actual LCRR responses can be determined and evaluated.

The hydraulic and hydrologic models will also be used to evaluate various water management scenarios using the response of important physical, ecological and societal resource indicators. These indicators will be identified in the study, computed on the basis of how they would have been impacted or reacted during the 2011 and past floods, and then compared with their response under the different flood mitigation measures considered. This will ensure that the ecological and societal concerns are taken into account when deciding on management options for flooding.

Collectively these activities will lead to decision support tools in the LCRR basin which will address flooding and flooding impacts. All of the important ecological, societal, and hydrologic information will be integrated into these tools so managers can make the best determinations of the appropriate actions to take.

This complements the development of flood forecasting tools and systems so that the public has the best available information from a scientific and social perspective.

The LCRR study will also rely on strong and on-going communications and an effective public outreach. Throughout the entire study, resources will be devoted to sharing the work plans, new information and data, and possible ways to move forward, with communities in the basin, stakeholders and public officials.

During the course of the study, the Study Board will produce several reports, products and tools that will be made available for the benefit of basin communities and stakeholders.In 2021, the Board will deliver its final report to the International Joint Commission. The report will contain recommendations for structural and non-structural flood mitigation measures. The recommendations will be thoroughly described andprioritized.Because the Board will have sought and considered stakeholders views on the acceptability and feasibility of the proposed measures, the expectations is that the measures will be viable and stand a better chance of being implemented by governments than previous IJC flood studies that recommended specific courses of action.