Mental health costs of flooding
Source: gov.uk (2025-04-04)

Including the impact of floods on people’s mental health for the first time.

A method for monetising the mental health costs of flooding

Christophe Viavattene (https://www.mdx.ac.uk/about-us/our-people/staff-directory/dr-christophe-viavattene/) 1, Sally Priest (https://www.mdx.ac.uk/about-us/our-people/staff-directory/prof-sally-priest/) 1, Jacqui Cotton 2 and Carolann Simmonds 2

1 Faculty of Science and Technology, Middlesex University, United Kingdom

2 Environment Agency, United Kingdom

The Environment Agency and risk management authorities routinely include the mental health impacts of flooding in investment decisions following research published in 2021 A method for monetising the mental health costs of flooding (https://assets.publishing.service.gov.uk/media/6038c2f28fa8f5048c84c37f/A_method_for_monetising_the_mental_health_costs_of_flooding_-_report.pdf).

Prior to this research, investment decisions focussed on the economic damages to homes, businesses and infrastructure. Although authorities knew that those affected by floods suffered with mental health conditions, there was insufficient robust data available to develop a new method. However, in 2017, Public Health England published the results of a national study on the impacts of flooding on mental health and well-being (https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-016-4000-2).

This study showed that people whose homes had been flooded suffered high levels of probable depression, anxiety and post-traumatic stress disorder. The study provided the figures needed to look at the economic damages for the first time. Subsequent studies showed these impacts could last for at least 2 years after the flood.

Impact

The Environment Agency project took this new data and used it to calculate the costs of the mental health impacts. These costs include treatment and medication, and loss of employment or earnings due to time off work. The project worked out the value to be £1,878 per adult per flood for shallow floods (less than 30cm of water in a home) to up to £4,136 per adult per flood for deeper, more severe floods (when water is over 1 metre deep). Deeper floods result in more possessions being lost and people being away from their homes for longer during repairs. This increases the impact on those affected, and thus increases the cost.

Alongside the research project, Environment Agency economists created clear guidance on how to use the economic cost information for those developing business cases for flood risk projects. The guidance was published in Mental health costs of flooding and erosion (https://www.gov.uk/government/publications/mental-health-costs-of-flooding-and-erosion/mental-health-costs-of-flooding-and-erosion).

Resources

Environment Agency. (2020). A method for monetising the mental health costs of flooding. Available at: https://www.gov.uk/flood-and-coastal-erosion-risk-management-research-reports/a-method-for-monetising-the-mental-health-costs-of-flooding (Accessed: 24 March 2025).

Environment Agency. (2021). Guidance: Mental health costs of flooding and erosion. Available at: https://www.gov.uk/government/publications/mental-health-costs-of-flooding-and-erosion/mental-health-costs-of-flooding-and-erosion (Accessed: 24 March 2025).

UK Health Security Agency. (2023). Guidance: How to recover from flooding. Available from: https://www.gov.uk/government/publications/flooding-and-health-advice-for-frontline-responders/how-to-recover-from-flooding - assessment-and-management-of-mental-health (https://www.gov.uk/government/publications/flooding-and-health-advice-for-frontline-responders/how-to-recover-from-flooding%20-%20assessment-and-management-of-mental-health) (Accessed: 24 March 2025).

UK Health Security Agency. (2023). Health effects of climate change in the UK 2023 report. Chapter 3 Climate change, flooding, coastal change and public health. Available at: https://assets.publishing.service.gov.uk/media/657086ad746930000d488919/HECC-report-2023-chapter-3-flooding.pdf (Accessed: 24 March 2025).

Funder

The research project was funded by the Flood and Coastal Erosion Risk Management (FCERM) research and development programme (https://www.gov.uk/government/organisations/flood-and-coastal-erosion-risk-management-research-and-development-programme).

Collaborators
- Flood Hazard Research Centre, Middlesex University
- Environment Agency
- Natural Resources Wales
- Public Health England
Research period
- 2017 to 2020
Impact period
- 2020 onward
Impact country
- England
Contributing to the areas of research interest
- 3 - Funding and investment