Floods are the most frequent and costly natural hazard in Europe, and their economic toll continues to rise, according to the latest report from Allianz Research on the economic impact of natural disasters. The study highlights how a single major flood can trigger multi-billion-euro costs for governments — with ripple effects extending far beyond the directly affected areas — while underscoring the growing economic value of climate adaptation.
Flood Costs Rising Sharply Across Europe
While the number of flood events has remained relatively stable — averaging around 46 per year in the 21st century — the financial damage per event has surged significantly. Total insured and uninsured losses rose by 17.8%, from €63.1 billion during 2000–2009 to €74.3 billion in 2010–2019. The July 2021 floods across Western Europe remain the costliest single flood event ever recorded, with damages estimated at €38 billion. This pushed total flood-related losses between 2020 and 2025 to €88.6 billion — roughly 40% higher than in the first decade of the century.
Floods already account for about 55% of all natural disaster losses across Europe. Alarmingly, 80% of these damages remain uninsured, meaning households, businesses, and governments bear the full burden. Under current climate trends and a scenario of +3°C global warming, average annual river flood losses across the EU and the UK could increase nearly sevenfold by 2100 — rising from €7.8 billion today to nearly €50 billion.
Impact on the Greek Economy
Allianz Research modeled the potential economic impact of a major European flood event occurring in 2027, with effects unfolding through 2030. In this scenario, Greece faces a cumulative investment decline of 13.9% — equivalent to approximately €4.7 billion — over the four-year period. That compares to reductions ranging from 10.5% in Norway to 14.6% in the Netherlands.
Household real disposable income is projected to fall between 3.9% and 5.4% across all countries studied — driven by reconstruction costs, temporary displacement, lost workdays, and higher prices. In Greece, household income is expected to drop by 5%.
The broader economy suffers too: infrastructure damage and supply chain disruptions push up prices and constrain output, slowing growth. While inflation rises by 0.2 percentage points in the UK, it climbs by a full 1.0 percentage point in Greece. GDP losses range from 0.4% in Norway to 1.0% in Spain — with Greece registering a €6.9 billion hit, or 0.8% of its GDP.
Public finances also deteriorate: the study indicates widening fiscal deficits across all examined countries, reflecting increased emergency spending and reduced tax revenues in the wake of large-scale flooding.