The Randstad metropolitan area is the largest agglomeration in The Netherlands. It is a ring of cities that surrounds a deep polder area of 2 to 6 metres below sea level. To get out of the Randstad, you have to cross the deepest polders. One can image that evacuating millions of people is nearly impossible at short notice and the dilemma of the first episode is: should we evacuate or not?
Then the drama unfolds. A mega-storm hits the coast. People get stuck in traffic. Families drift apart and children drown in cold water.
Official Trailer ‘Als de dijken breken’ (in Dutch).
Is this real?
The first episode ignited a discussion among my colleagues on the realism of the series. I pointed at the aspects that I am familiar with. The flood maps in the crisis response room and the notion of a cascading effect on the infrastructure are credible. A remark by the minister that it will take until 2050 before all flood defences have a safety level according to new standards is true.
The flood scenario and the narrow escape of the people in the series are dramatized. I find it hard to believe that a child can cycle through a storm with wind speeds of up to 180 km/h. However, a debate about details misses the crucial point: this series is of great help in raising public awareness of flood risk.
After the first episode of the TV drama, the real minister of Infrastructure and Environment was invited by talk show hosts to discuss the evacuation options in case of a flood emergency.
What should we do?
The Dutch are confident: we have the Delta Works, we have water expertise. The last flood disaster occurred in 1953, when a storm surge hit the south-western provinces and 1,836 people drowned. High river discharges in 1993 and 1995, a collapsing peat dike in 2003 and heavy rainfall in 2016 acted as wake-up calls.
Feeling a bit uncomfortable after watching the TV drama, my family and friends asked what to do in case of an emergency situation. One of the take home messages of the series is: evacuate in a vertical direction. Go to the upper floors of a tall building. Be prepared for a stay without basic services, such as tap water and electricity.
The website Overstroomik.nl shows what can happen to you and gives practical advice. Just enter your zip code of four digits and two letters.
It says: ‘You have less than 1% probability to experience a maximum flood level of 2.5 metre in your lifetime. That can also be tomorrow.’ This confirms my intuition, because I live 2.5 metres below sea level in an area that was unaffected by the floods of 1953 and 1916. Over the past decades, the government has invested a lot in flood protection.
Your own flood risk analysis
Aqueduct and ThinkHazard! are global tools for flood risk assessment. You can study the situation on a regional scale, anywhere on the planet. I zoomed in on The Netherlands and made two snapshots.
At first sight, the three websites appear to send a slightly different message, which is a matter of definitions, settings, the underlying data and the visualisation. It takes time to get familiar with the concepts and the interface.
For instance, in Aqueduct you can change the protection level. A protection level of 10 years (the default setting) means that you are protected against anything equal to, or smaller than, a 10-year flood. Subsequently the tool computes the probability of inland flooding and the annual expected damage. The actual protection level in The Netherlands is much higher.
ThinkHazard! shows several hazards in one convenient overview. It makes quite a statement for my province: ‘… potentially damaging and life-threatening river floods are expected to occur at least once in the next 10 years.’ It sounds less reassuring than Overstroomik.nl, but the difference is in the spatial scale and the definitions.
ThinkHazard! is a quick scan tool on a regional scale. It seems to overestimate the risk, so you need more information about the local situation. Further harmonisation of the flood risk tools is desirable, in order to give a clear and personalised message to the general public.
How about the future?
In the third episode of the TV drama, the meteorologist says to the prime minister: ‘we must ask ourselves, why we want to live below sea level.’ By then the storm is over and the Randstad is inundated. There are thousands of causalities and the government is about to be evacuated from The Hague to Apeldoorn.
One week later, this question is still ringing in my head. It somehow mixed with the news that the North Pole is experiencing record temperatures – another signal that the climate is changing. What if the arctic has reached a tipping point and climate change speeds up? For how long can we defend our low-lying country against sea level rise and land subsidence?
Although a large part of the population and important economic sectors are situated below sea level, the flood risk awareness is low in The Netherlands. We are well protected against flooding from coastal and river floods.
A new TV drama is raising the awareness. The Dutch are watching and discussing a thought-provoking simulation of an extreme flood scenario. With 1.75 million viewers, the episodes have reached at least 10% of the population. This stimulates the general public to search for information on flood risk and to prepare for the exceptional situation that the dunes and dikes are failing.