River Floods

The document analyzes river flood risks in the EU27, finding that combined climate and socio-economic changes could increase expected annual damages (EAD) from €5.5 billion in the baseline period to €97.9 billion by the 2080s under a medium-high emission scenario (A1B). It emphasizes that socio-economic growth is as significant a driver of damage as climate change. Adaptation to maintain 1-in-100-year protection levels is projected to provide substantial benefits, reducing EAD by up to €50 billion per year by the 2080s, with estimated annual adaptation costs rising to €7.9 billion in the same period. The report highlights significant uncertainty across different climate models, which can project opposite directions of risk change at local levels, necessitating flexible and robust adaptation strategies.

• Under the A1B medium-high emission scenario, the number of people potentially affected by river flooding in the EU27 (Expected Annual People - EAP) is projected to rise from a baseline of approximately 167,000 to 300,000 by the 2020s and 359,000 by the 2080s.
• Expected annual damage (EAD) from river floods in the EU27 is projected to increase from a baseline of €5.5 billion to €20.4 billion by the 2020s, €45.9 billion by the 2050s, and €97.9 billion by the 2080s under the A1B scenario, assuming no adaptation.
• Socio-economic drivers, such as population and economic growth, are as important as climate change in determining future flood damages. The marginal effect of climate change alone is estimated to increase EAD by €9 billion/year by the 2020s and €50 billion/year by the 2080s under the A1B scenario.
• Under the E1 mitigation scenario (aligned with the EU 2 degrees target), the projected EAD for the EU27 is lower than the A1B scenario, reaching €68.2 billion by the 2080s, with the marginal impact of climate change estimated at €30 billion/year by that time.
• Maintaining 1-in-100-year flood protection levels in the EU27 under the A1B scenario would provide annual benefits (avoided damages) of €8 billion by the 2020s, €19 billion by the 2050s, and €50 billion by the 2080s.
• The annual costs to maintain minimum 1-in-100-year protection levels in the EU27 under the A1B scenario are estimated at €1.7 billion by the 2020s, €3.4 billion by the 2050s, and €7.9 billion by the 2080s.
• There is significant uncertainty and variability across climate models; some models project opposite directions of change in flood risk at the country or local level, which necessitates flexible and iterative adaptation strategies.
• The greatest increases in flood damage specifically related to climate change (above socio-economic growth) are projected for the UK, Italy, Slovenia, Belgium, and the Netherlands.
• A hedonic price study in Prague, Czech Republic, found that flood risks significantly reduce property values, with a central estimated value decrease of -8.5%.

APA

Feyen, L., & Watkiss, P. (2011). River Floods. Stockholm Environment Institute. https://www.sei.org/mediamanager/documents/Publications/sei-climatecost-river-floods.pdf

Chicago

Feyen, Luc, and Paul Watkiss. River Floods. Stockholm Environment Institute, 2011. https://www.sei.org/mediamanager/documents/Publications/sei-climatecost-river-floods.pdf.

Wikipedia

{{cite report |last1=Feyen |first1=Luc |last2=Watkiss |first2=Paul |title=River Floods |publisher=Stockholm Environment Institute |date=September 2011 |url=https://www.sei.org/mediamanager/documents/Publications/sei-climatecost-river-floods.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{feyen2011river, author = {Feyen, Luc and Watkiss, Paul}, title = {{River Floods}}, institution = {Stockholm Environment Institute}, year = {2011}, month = sep, url = {https://www.sei.org/mediamanager/documents/Publications/sei-climatecost-river-floods.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }