POST (Parliamentary Office of Science and Technology)
Natural mitigation of flood risk
The UK’s flood risk from rivers, surface water and ground-water is projected to increase with climate change. Natural flood management (NFM) can be described as using the natural features of the land to store and slow down the flow of water. NFM is being piloted across the UK and its expansion is an objective of the Government’s 25 Year Environment Plan. This POSTnote examines the evidence for the effectiveness of NFM at reducing flood risk, and successful governance approaches to implementing NFM measures.
Download the full report
- Natural mitigation of flood risk (PDF, 363 KB)
The UK Government’s 2017 Climate Change Risk Assessment report identified increased flood risk as one of the UK’s top climate change risks. In some areas, peak flows (the maximum flow of water at a given point in a river during a flood event) have been increasing at a rate of over 5% per decade. The winter of 2019/20 saw extensive flooding caused by Storms Ciara and Dennis in parts of the UK during the wettest February on record, and a record-breaking number of Environment Agency flood warnings were issued. The UK’s vulnerability and exposure to flood risk continues to grow; approximately 10% of new homes are built in high flood risk areas, and over 500 major infrastructure assets are vulnerable to flooding.
NFM is an approach to managing flood risk that aims to create, restore or alter landscape features to reduce flooding. It has been highlighted as an important flood mitigation strategy in the 2018 National Infrastructure Assessment and the 2019 draft National Flood and Coastal Erosion Risk Management Strategy for England. The Government’s 25 Year Environment Plan also aims to expand use of NFM, setting out £15 million of investment into research and implementation between 2018–2021. Measures are currently being applied or considered in over 236 areas throughout the UK.
Key points in this POSTnote include:
- NFM can help mitigate the impacts of smaller, more frequent floods and can be a low-cost option for helping to manage flood risk for smaller communities.
- However, as it is not yet proven to mitigate the impacts of extreme flooding or flooding in large catchments, NFM should be used in conjunction with built flood infrastructure.
- NFM delivers many environmental co-benefits, such as carbon storage, water quality protection and biodiversity enhancement, allowing environmental objectives to be addressed simultaneously.
- Successfully implementing NFM requires working in complex multi-stakeholder partnerships, with local communities and land managers participating in decisions.
- Barriers to the implementation of NFM include a lack of public awareness, administrative barriers, and insufficient long-term incentives for land managers.
POSTnotes are based on literature reviews and interviews with a range of stakeholders and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:
Lydia Burgess Gamble, Environment Agency*
Chris Uttley, Environment Agency*
Jonathan Simm, HR Wallingford*
Rob Collins, The Rivers Trust
Paul Cobbing, National Flood Forum
Alison Fergusson, Ofwat*
Sharma Jencitis, United Utilities
Brendan Freeman, Committee on Climate Change
Professor Simon Dadson, University of Oxford/CEH*
Dr Chris Short, University of Gloucestershire*
Dr Kirsty Holstead, University of St Andrews*
Dr Nick Chappell, University of Lancaster/ President of UK Hydrological Society*
Professor Martin Evans, University of Manchester
Mhari Barnes, NFU
Stewart Clarke, National Trust
Dr Tom Nisbet, Forest Research*
Barry Hankin, JBA*
Professor Joanna Clark, University of Reading
*Denotes people who also acted as external reviewers of the briefing
|Academic Fellowships||Upcoming work||POST Publications|
Latest News from
POST (Parliamentary Office of Science and Technology)
Advances in vaccine technologies30/09/2021 14:38:00
This POSTnote provides an overview of vaccine development and technologies. It also covers opportunities and challenges to vaccine discovery and manufacture, as well as policy approaches to stimulate vaccine research and development (R&D) in the UK.
Smart Cities24/09/2021 16:10:00
"Smart cities" describes places that incorporate a range of technologies (especially those that collect and use data) to address economic, social, and environmental challenges. Projects usually take place in urban areas, but are also deployed in rural settings. This POSTnote looks at smart city innovation in the UK and the technologies involved. It considers the factors driving the adoption of smart city technologies, and the potential benefits, barriers and risks associated with their implementation.
Blue carbon06/09/2021 16:25:00
Marine ecosystems around the UK can both increase and decrease atmospheric carbon dioxide levels. Carbon loss and gain globally by these ecosystems has the potential to influence climate change.
Local nature recovery strategies06/09/2021 11:25:00
The UK Government is introducing Local Nature Recovery Strategies (LNRS) from April 2022 to map where local habitat improvement and restoration could address national-scale environmental objectives.
Environmental housing standards02/09/2021 15:15:15
Buildings have varied impacts on the environment, arising from energy, water and land use as well as the release of pollutants.
Mental health impacts of the COVID-19 pandemic on adults23/07/2021 12:33:00
The impact of the COVID-19 pandemic is a significant public health concern, with a growing body of research describing the effects on the population since March 2020.
Coastal Management16/07/2021 15:33:00
The UK coastline is shaped by interactions between complex social, ecological, and physical processes.
Low-carbon hydrogen supply11/06/2021 15:33:00
Hydrogen could play a significant role in tackling climate change. Using it does not produce carbon dioxide, so it could replace fossil fuels in a range of applications.