Building Resilient Watersheds as Natural Infrastructure for Climate Change Adaptation
Wednesday June 28 12:15pm-1:15pm
Leads: Roger Phillips (Matrix Solutions Inc. & University of Toronto), Joanna Eyquem (Intact Centre on Climate Adaptation, University of Waterloo) and Quentin Chiotti (Matrix Solutions Inc.)
Natural channel design and watershed management have developed over recent decades with a focus on river habitat restoration, while also facilitating management of flooding and erosion hazards. With a growing need for public investment in climate adaptation, channels and floodplains are increasingly important as natural infrastructure assets to increase climate change resilience. Canada’s new National Adaptation Strategy, including the renewed Disaster Mitigation and Adaptation Fund, promote greater consideration and investment in natural infrastructure, and natural channels are the centrepiece of many projects. This is an opportunity for industry to increase the use of natural infrastructure, as a complement to grey infrastructure, for climate adaptation. This session intends to explore the evolving science of flood and erosion hazard management that is contributing to building more resilient watersheds, including novel approaches for planning and designing natural stream corridors. To emphasize downstream connectivity in the drainage network and integrated watershed management, this session aims to include a variety of examples across the landscape from rural to urban watercourses and from headwaters to estuaries.
Keywords: Climate Adaptation, Natural Hazard Management, Thinking Upstream and Downstream, Nature-based Solutions, Strategic Approaches
Presentations made available will be posted here after the conference.
Sean Ferguson & Ivana Vouk
National Research Council Canada, Ottawa, Canada
Nature-based solutions (NbS) depend on, or mimic, natural system processes to provide flood and erosion risk management functions, while delivering environmental and other societal co-benefits (Vouk et al., 2021). The benefits of preserving and restoring natural system processes to support flood and erosion risk management objectives are well known. Despite increasing interest in NbS in recent decades, there are a number of challenges preventing broader uptake and implementation of NbS in Canada. Vouk et al. (2021) summarized needs and opportunities to support deployment of NbS to manage flooding and erosion risks based on a review of published literature and stakeholder interviews. The report highlighted a need for evidence-based, technical guidance to support design and implementation of NbS in Canada’s diverse river systems. The National Research Council of Canada is currently leading a multi-year project to address needs pertaining to technical guidance at the national scale in collaboration with members from Canadian municipalities, academia, non-profit organizations, private industry, and other government departments. Findings and lessons learned from three ongoing NbS pilot projects in distinct geographic settings in Canada will be integrated into a new guideline document to provide modern, evidence-based guidance for design and implementation. In addition, the new guidelines will draw information from existing regional and international guidance, relevant literature, and past case studies. This presentation highlights the scope and objectives of the three pilot projects located in watersheds in Surrey, British Columbia; Calgary, Alberta; and the Greater Toronto Area of Ontario. The presentation also highlights future plans for guideline development as well as potential opportunities for collaboration.
Vouk, I., Pilechi, V., Provan, M., & Murphy, E. (2021). Nature-Based Solutions for Coastal and Riverine Flood and Erosion Risk Management. Canadian Standards Association.
Fred Dobbs, Laura Wensink & Sarah Campbell
Nottawasaga Valley Conservation Authority, Utopia, Canada
River restoration programs often fail due to a wide range of factors that may include a lack of clear science-based restoration goaIs, limitations on funding that restrict the scope of works, and challenges associated with developing an appropriate performance monitoring strategy that incorporates defensible environmental targets. Another limiting factor is the need to integrate a suite of effective river morphology-based restoration techniques into an aquatic habitat improvement strategy. The Nottawasaga River Restoration Program (NRRP) provides a case study for an integrated multi-partner fish habitat restoration initiative that has been designed to address the challenges listed above. The goal of the NRRP, entering its 6th year of implementation, is to improve water quality and enhance populations of both native fish and naturalized fish which support recreational fisheries. The key strategy is to start restoration work where rivers emerge from the Niagara Escarpment region as clean water sources and coldwater fish habitats, and extend the high quality water and fish habitat downstream into flatter land forms which have been impacted by agricultural and urban land uses. Recognizing the high specific heat of water, the restoration approach focusses on starting at the upstream end of target restoration reaches and working downstream in a step-wise fashion in order to “keep the cold water cold”. Restoration target reaches have been identified using stream temperature, fish community and benthic invertebrate data. Target reaches typically represent zones of rapid warming where shade from riparian vegetation has been impacted and a lack of root structure has lead to accelerated bank erosion. The NRRP has implemented an innovative suite of restoration techniques including channel realignments, floodplain construction, rooting shelf excavation, installation of toe protection comprised of large woody material harvested from invasive trees, applications of natural sod mats, excluding livestock with fencing and riparian reforestation.
Intact Centre on Climate Adaptation, University of Waterloo, Montreal, Canada
There is a globally recognized opportunity to “scale-up” approaches that work with nature to reduce climate impacts, including flood and erosion risk. This opportunity is reflected in Target 11 of the Kunming-Montreal Global Framework Directive that calls for restoring, maintaining and enhancing nature’s contributions to people. However, nature-based approaches are not currently part of the routine flood and erosion risk management toolbox. One key challenge is that effective nature-based approaches to flood and erosion risk management typically require work at the scale of natural systems, such as watersheds or coastal cells.
This presentation builds on collaborative research undertaken by CSA Group and the Intact Centre with over 40 subject matter experts across Canada. An overview of watershed management approaches within different Canadian provinces will be provided, with focus on flood and erosion management using nature-based solutions. Trends in federal funding of flood risk management projects will be presented as context for the spatial scale at which work has been completed to date. Existing best practices will be identified together with opportunities for improvement in how nature-based flood solutions are applied at the watershed-scale, within Ontario and beyond.
The scaling-up of nature-based solutions for flood and erosion management is clearly not only a technical challenge. Significant efforts to reduce flooding and erosion risks remain focused, and funded, at the community or project-scale. When undertaken in the context of a long-term strategic approach to watershed management, localized approaches can be prioritized and sequenced, work synergistically to reduce risk, avoid unintended or undesirable consequences downstream, and generate larger-scale and multiple benefits for both people and nature. Adopting such approaches will support all levels of governments in truly realizing the power of nature for flood and erosion risk management.