01 · The problem
What is happening
Rotterdam sits in the Rhine-Meuse delta, with the majority of its area below sea level. Protection combines dikes, the Maeslant storm surge barrier, pumping and a national Delta Programme that plans decades ahead for sea level rise and changing river discharge. The city has also pioneered adaptation inside the flood defences, including water plazas, green roofs and water storage in public space to manage intense rainfall.
Moderate severity. Material effects on people or ecosystems; actively managed. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
02 · Causes
Why it is happening
- 01
Low-lying delta geography
Most of the city lies below sea level in the Rhine-Meuse delta.
- 02
Sea level rise
Rising mean sea level increases the load on defences and the frequency of extreme water levels.
- 03
Intense rainfall and river discharge
Heavy downpours and high river flows can overwhelm drainage inside the defences.
03 · Impacts
Who and what it affects
- 01
Permanent dependence on defences
Safety relies on continuously maintained dikes, barriers and pumps rather than natural elevation.
- 02
Rainfall flooding inside the defences
Intense downpours can flood streets and basements even when the sea and rivers are held back.
- 03
Rising long-term adaptation cost
Higher sea level means defences must be raised, strengthened and eventually rethought.
04 · Solutions
Documented approaches
Storm surge barriers and dikes
The Maeslant barrier and the national dike system close off or hold back extreme water levels.
Expected effectProvides a very high standard of protection, maintained and upgraded over time.
Water plazas and green roofs
Public squares designed to hold stormwater temporarily, plus roof-level retention.
Expected effectReduces peak load on drainage during intense rainfall while adding public space.
Adaptive Delta Programme planning
A national programme that revisits assumptions and measures regularly as conditions change.
Expected effectAvoids locking in decisions based on a single sea level scenario.
05 · Key indicators
What can be measured
- Land below sea level
- Majority of city area
Municipal and national sources describe the greater part of Rotterdam as lying below mean sea level.
- Storm surge barrier
- Maeslantkering1997
Completed movable storm surge barrier protecting the Nieuwe Waterweg, closing automatically at defined water levels.
06 · Sources
Where this comes from
- [1]Delta ProgrammeGovernment of the Netherlandsenglish.deltaprogramma.nl(opens in a new tab)
- [2]Rotterdam Climate Adaptation StrategyGemeente Rotterdamrotterdam.nl(opens in a new tab)
Links open the publishing organisation's site. Some point to the publisher's main page, where the named report or dataset can be found.