Floods: prevention, preparedness, response and recovery

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A number of extreme flooding events have occurred in Canada over the last few decades, and as a result of climate change, are growing in both frequency and magnitude. Manitoba experienced intense flooding in 1997 which resulted in the relocation of 25,450 evacuees and damage to more than 1,000 homes – extreme floods occurred again in the province in 2009 and 2011. A few years later in 2013, Alberta experienced flooding that washed across one-quarter of the province and more than 100,000 residents were told to leave their homes. It was the most economically devastating natural disaster in Canada’s history and economists have projected that costs from the flood exceed $6 billion. In the spring of 2017, flooding similarly affected a vast area within Quebec; nearly 3000 residents were evacuated from their homes in the municipalities of Pontiac, Rigaud, and Montreal, and water contamination advisories were in place across these regions. States of emergency were declared in all of these cases and flood fighting efforts involved thousands of emergency staff, officials, volunteers, and military personnel.

From an environmental health perspective, flooding may increase the risks of harm and disease, and may also affect well-being. Moreover, there can be human health impacts throughout the stages of these types of disasters. This topic page provides a collection of key resources on flooding, organized according to flood stages in order to draw attention to critical points of concern: 1) Prevention; 2) Preparedness; 4) Response and Health Effects; and 4) Recovery. Key points of interest range from developing resilient infrastructure and public flood risk education campaigns to addressing mould, contamination, home remediation, and mental health in the recovery stages after a flood.

NCCEH Resources

  • Mould investigation toolkit (2015)
    This toolkit provides PHIs and EHOs with some of the tools for evaluating indoor environments for mould (and other microorganisms), providing information, conducting walkthrough investigations, and understanding laboratory and consultant reports that they may be asked to review.

Selected External Resources


This section’s resources focus on steps that can be taken to mitigate flood risks ahead of time and prevent floods from developing into large scale emergencies. This includes actions at the municipal level, such as integrating green building and infrastructure design to build resiliency, as well as larger provincial and federal efforts to coordinate the management of natural resources, restore natural flood plains, and support structural adaptation measures.

  • Flood prevention (City of Edmonton, 2018 )
    This webpage outlines Edmonton’s flood prevention strategy and their Flood Prevention Program. The program is aimed at addressing flood issues in 43 at-risk neighbourhoods and focuses primarily on drainage improvement projects and retrofitted stormwater management facilities.
  • Health co-benefits of green building design strategies and community resilience to urban flooding: a systematic review of the evidence (Houghton & Castillo-Salgado, 2017)
    This systematic review examined evidence linking green building strategies in the Leadership in Energy and Environmental Design (LEED) rating system with the potential to reduce negative health outcomes following flooding events. Green building design was found to reduce the risk of waterborne disease, flood-related morbidity and mortality, and psychological harm.
  • Defining, describing, and categorizing public health infrastructure priorities for tropical cyclone, flood, storm, tornado, and tsunami-related disasters (Ryan et al., 2016)
    This review identifies and categorizes public health infrastructure priorities for flood and other water-related natural disasters. The highest priority areas were water, sanitation, communication, physical structure, power, governance, prevention, supplies, service, transport, and surveillance. Workforce was identified as the highest priority area related to public health infrastructure and disasters and had the greatest impact on the performance of health services.
  • Preventing disaster before it strikes: developing a Canadian standard for new flood-resilient residential communities (Moudrak and Feltmate, 2013)
    This report highlights the need for flood risk education in Canada, identifies priority areas of focus, and develops best practices for building new residential communities that are more resilient to flooding. Best practices were developed using criteria based on national applicability, effectiveness in reducing flood damage from severe rain events, technical feasibility for implementation, and cost-effectiveness.
  • Adaptation measures for floods, storm surges, and sea level rise (Langis, 2013)
    This report describes the impacts of climate change on extreme weather events (such as rising sea level, storm surges, and flooding) and discusses adaptation measures to prepare for and limit these impacts. The report addresses adaptations at the individual level as well as infrastructure, road, ecosystem, and coastal adaptation measures.
  • Reducing flood damage (Government of Canada, 2013)
    This webpage offers historical background of flooding in Canada, relevant protective legislation and presented detailed information on non-structural measures (such as floodplain management, forecasting and warning, and emergency measures) as well as structural measures (such as dams, channel improvements, ice booms, and flood proofing)
  • Best practices on flood prevention, protection and mitigation (European Union, 2004)
    This report is a “best practices” document that examines the United Nations and Economic Commission for Europe (UN/ECE) Guidelines on Sustainable flood prevention (2000). The report focuses on the coordinated management of water, land, and natural resources, the restoration of natural flood zones, mitigation measures to reduce vulnerability, flood forecasting and warning, the planning of alert, rescue, and safety measures, compensation measures for victims of flood disasters (including insurance systems), and preventative measures depending on the hydrological and environmental circumstances.


Flood preparation measures can include initiatives to improve flood risk awareness, public engagement on risk management, and efforts to minimize flood damage and mitigate health risks. More broadly, the resources included cover themes around individual protection (regarding personal safety and property) and how to prepare for hazards both at home and at a regional level.

  • Get prepared – floods (Government of Canada, 2018)
    This webpage acts as a base for federally provided information on preparing for floods (organized for the public). The webpage includes links to resources for each province and territory and outlines the federal role in flood-related disasters. There are also public links that describe what to do before, during, and after a flood.
  • Flooding in First Nation communities (Indigenous and Northern Affairs Canada, Government of Canada, 2018)
    This webpage provides background information on flood risks to First Nation communities, identifies flood risks by region (and points to relevant First Nations regional organizations responsible for emergency response), and discusses flood preparation measures and examples from each region.
  • Engaging Canadians in flood risk management: lessons from the international community (Centre for International Governance Innovation, 2017)
    This policy brief provides a scan of international initiatives intended to foster flood risk awareness, engage the public, and encourage changes that support flood risk management. Two key lessons for flood risk management policy are discussed and the brief provides three policy recommendations on how to better engage Canadians in flood risk management.
  • Climate change and the preparedness of Canadian provinces and Yukon to limit potential flood damage (Feltmate and Moudrak, 2016)
    This report assesses the preparedness of Canada’s provinces and Yukon to limit climate change related flood damage. The report also provides direction on how to build upon efforts to limit flood risk. The included assessment is based on a survey examining flood plain mapping, drainage maintenance, home adaptation, electricity supply, drinking water and wastewater systems, and public health and safety, among other criteria.
  • How to prepare for a flood (Federal Emergency Management Agency, 2014)
    This hazard-specific guide provides information on the basics of each flood hazard, how individuals can protect themselves and their property, and what steps they can take to prepare for flood-related disasters.
  • Cities and flooding: a guide to integrated urban flood risk management for the 21st century (Jho et al, 2012)
    This guidance document provides comprehensive, forward-looking operational guidance on how to manage the risk of floods in changing urban environments in the context of climate change. It serves as a primer for decision- and policy-makers, technical specialists, government officials, and stakeholders in the community and private sectors. The document outlines key areas for policy direction and an integrated strategic approach for urban flood risk management.

Response and Health Effects

This section includes resources that delineate the various health effects of flooding, such as issues surrounding drinking water contamination (and supply), sewage backup and gastroenteric outcomes, as well as short-term dangers and safety issues. The resources also describe actions to take, how to build awareness around these risks, and recommendations for addressing some of these health effects.

  • Climate change, floods, and your health (Public Health Agency of Canada, 2018)
    This public health factsheet identifies the short-term dangers (such as drowning and injuries) and long-term dangers (such as disease spread through water contamination and sewage backup, food contamination, and insects, as well as carbon monoxide poisoning, and mental health effects) of flooding. The factsheet also outlines actions to take to mitigate these health risks.
  • The effect of flooding on private drinking water systems (Public Health Ontario, 2018)
    This public health blog post summarizes the effects of flooding on private drinking water systems, what steps the public can take to mitigate there risks, and highlights the link to private sewage systems, sewage backup, and possible contamination of personal water supplies.
  • Surface water flooding, groundwater contamination, and enteric disease in developed countries: a scoping review of connections and consequences (Andrade et al., 2018)
    This systematic review identifies and synthesizes the literature on surface flooding, groundwater contamination, and human gastroenteric outcomes. The authors discuss strategies to increase awareness about potential sources of contamination and to motivate precautionary behaviour.
  • Natural disasters and severe weather – floods (Centres for Disease Control and Prevention, Atlanta GA, 2017)
    This webpage provides flood resources that span the timeline of flood emergencies. The webpage focuses on flood readiness, worker safety, water safety, what to do after storms (with sections on re-entering, cleanup, and personal hygiene), and learning and awareness.
  • Health effects of flooding in Canada: a 2015 review and description of gaps in research (Burton et al., 2016)
    This review summarizes the epidemiological evidence of flood-related health effects and the Canadian susceptibility to these effects. Recommendations are also offered for addressing the health-related effects of flooding.
  • Potential flood hazards and personal safety precautions (Emergency Management BC, 2007)
    This safety factsheet describes serious safety and health hazards from flooding. The factsheet also discusses a number of precautions that people can take to prevent illness and serious injury. Links are also provided on several specific hazards and precautions, such as electrical safety, natural gas, and water advisories.


The recovery resources provided below tend to focus on post-flood effects and actions to take after a flood has ended. Much of the work on recovery focuses on physical elements of remediation (such as dealing with mould, structural issues, and using appropriate protective equipment in the process of remediating) - which have been included in this resource list - but there is also a great deal of focus on the social and mental aspects of recovery. Because of this growing awareness about the mental health impacts of flooding and other disasters, resources have been included that explore post-traumatic stress disorder, well-being, long-term stressors, and community networks, all in the context of flooding.

  • Developing a research-specific emergency management programme for municipal resilience following the 2013 flood in southern Alberta (Bowerman, 2017)
    This article discusses the Calgary Emergency Management Agency’s emergency management programme for community leaders that came about in the wake of the 2013 Alberta floods. The article highlights the background and realisation of this program, offers recommendations for challenges and limitations, and considers its development going forward.
  • Incidence and risk factors for post-traumatic stress disorder in a population affected by a severe flood (Fontalba-Navas et al., 2017)
    This study aimed to assess the risk of developing post-traumatic stress disorder (PTSD) symptoms in people who lived in an area affected by extreme flooding (as well as the sociodemographic risk factors associated with this condition). Individuals who did reside in these areas were at much higher risk for PTSD symptoms, and among the sociodemographic factors, material and financial losses were strongly associated with the onset of PTSD.
  • No calm after the storm: a systematic review of human health following flood and storm disasters (Saulnier et al., 2017)
    This systematic review analyzed morbidity and mortality linked to floods or storm disasters with attention to how the burden of disease varies during different phases after floods and storms. The review included 113 studies and found that poisonings, wounds, gastrointestinal infections, and skin or soft tissue infections all increased after storms and that gastrointestinal infections were more frequent after floods. The majority of health changes occurred within four weeks of floods or storms.
  • Wellbeing in the aftermath of floods (Walker-Springett, 2017)
    This study analyzed several processes that explain wellbeing for those experiencing flooding. Key pathways to wellbeing outcomes included perceptions of lack of agency, dislocation from the home, and disrupted futures. There were offsetting positive impacts to these negative effects via community networks and interactions.
  • Flooding and mental health: a systematic review (Fernandez et al., 2015)
    This systematic review mapped and assessed scientific evidence on mental health impacts of floods caused by extensive periods of heavy rain in river catchments. Four broad areas of findings were identified: 1) main mental health disorders, post-traumatic stress disorder, depression and anxiety; 2) factors associated with mental health among those affected by floods; 3) the narratives associated with flooding and long-term stressors; and 4) management actions.
  • The impact of flood and post-flood cleaning on airborne microbiological and particle contamination in residential houses (He et al., 2014)
    This study analyzed results from a comprehensive, multi-parameter indoor and outdoor measurement campaign to assess the effects of flooding on air quality and the role of prompt cleaning activities in reducing airborne exposure risks.
  • Cleaning the house after a flood (Alberta Health Services, 2013)
    This short guidance document provides advice on how to safely clean and prepare homes for re-entry. The guide focuses on: personal protective equipment; food safety; floors; walls; ceilings; electrical equipment, lights, fixtures, and wiring; appliances; furnaces and water heaters; plumbing; and what to discard and what to save.
  • Cleaning up after the flood: a guide for homeowners (Saskatchewan Ministry of Health, 2011)
    This detailed factsheet and guide serves to assist people in cleaning up homes that have been flooded in order to prevent contamination and mitigate dangers. The guide focuses on: contamination from raw sewage and other pollutants; electrical systems, gas systems and appliances (regarding the risks of electrical shock or explosion); ceiling and wall damage and structural weakness; and mould and mildew resulting from dampness.


This list is not intended to be exhaustive. Omission of a resource does not preclude it from having value.

Last updated Sep 18, 2019