Our greatest challenge or our biggest opportunity?

Globally, ~44% of all disaster events between 2000 and 2019 were floods.

Greece has recorded ~2,000 floods since 1886, and they're getting worse. Rapid urbanisation and warming are intensifying each event, with recent storms already 10–15% wetter than they would have been without climate change.

However, there are many well-established + viable ways of turning the floods in Greece from 'disasters' into 'resources':

1. Unseal the city

Turn cities into sponges; an approach pioneered across 30 cities in China.

• Permeable pavements – water drains through, recharging groundwater (Kiacrete, Imperial College London)

• Rain gardens – absorb rain before it hits the street (~88% runoff reduction)

• Urban wetlands – hold excess rainfall and release it slowly (~33% peak discharge reduction)

2. Give rivers room

Stop containing rivers. Let them spread safely.

• Floodplain restoration – the Dutch cut peak water levels by 35cm just by moving one dike inland

• Riparian forests – trees along riverbanks slow water flow, trap sediment, and prevent bank collapse

• Nature-based > concrete – 2.9x return on investment vs 1.5x for grey infrastructure

3. Predict it

Time is the cheapest intervention.

• Google DeepMind – forecasts floods in 100+ countries with 7-day lead times (as accurate as same-day models used to be)

• Sewer sensors – ultrasound sensors in manholes detect rising water and trigger flood warnings (already deployed by EYDAP!)

4. Defend it

When water comes, defences need to be faster than sandbags.

• Self-activating barriers – sensors detect rising water and deploy automatically

• Smart drainage – AI-controlled gates divert water into storage in real time (CENTAUR, The University of Sheffield)

• Debris retention basins – trap sediment before it blocks rivers and culverts

5. Build for it

Flood-proof the infrastructure itself.

• Elevated ground floors – raising by just 1m reduces flood damage and can halve insurance premiums

• Flood-resilient retrofits – raised electrics, waterproof lower floors, flood-proof doors

• Blue-green building codes – mandatory permeable surfaces and green roofs, turning every new build into part of the solution

The chain

Unseal → Give room → Predict → Defend → Adapt

Every link exists. The barrier isn't technology. It's implementation.

Sources

• Natural Hazards (Springer) – Temporal distribution of floods in Greece (bar graph)

• University of Athens (EKPA) – Historic Floods interactive platform (map)

• UNDRR – The human cost of disasters 2000–2019 (44% of disasters are floods)

• Euronews – Greece storms made wetter by climate change (World Weather Attribution)

• Imperial College London – Kiacrete, a puddle-free pavement surface

• ASCE Library – Rain gardens (~88% runoff reduction)

• University of Cape Town – Urban wetlands and peak discharge reduction

• Climate-ADAPT (EEA) – Room for the River Waal: protecting the city of Nijmegen (35cm reduction)

• European Investment Bank – Nature-based solutions for floods in Thessaly (2.9x vs 1.5x)

• Google Research – A flood forecasting AI model trained and evaluated globally

• Swarmchestrate – Athens sewer sensors for flood prevention (EYDAP)

• The University of Sheffield – CENTAUR: using AI to reduce urban flooding

• FloodList – Elevating buildings in flood-prone locations

• Wikipedia – Sponge cities (China, 30 pilot cities)

• Bank of Greece – Climate change projections for Greece