Every home page on Buurtje.nl shows two water risks that people tend to mix up. The first is heavy rain: a cloudburst the sewers cannot handle, so water stays on the street and in the garden. The second is flooding: a dyke that fails or a river that bursts its banks. The first can happen on any street, even on the high sandy ground of the Veluwe. The second depends entirely on where you live and how strong the dykes are there.
We laid both maps over the nearly 64,000 owner-occupied homes for sale in our listings this morning. How common is an elevated risk, which cities stand out, and do asking prices reflect it?
A word on what these figures are. They come from the national maps of the Klimaateffectatlas, the Dutch climate impact atlas: model calculations based on elevation data, not measurements at your front door. A raised threshold, a working drain or a garden that has been built up will not show on such a map. They are indications per address, and the prices are asking prices, not sale prices.
Heavy rain: water on the street after a cloudburst
The map works with a very heavy shower of 70 millimetres in two hours, more than the sewer on an ordinary street can take. We call the risk elevated when 20 centimetres of water or more is expected to stand around the home, and medium at 15 to 20 centimetres, or when 20 centimetres is only reached in an even more extreme storm. A home that sits half a metre or more below its surroundings moves up one level, because water runs to the lowest point.
Of the homes for sale in our listings, 24% have an elevated indication for heavy rain, 34% a medium one and 38% a low one. The rest have no indication. So this is not rare: almost one in four homes.
Apartments score elevated more often (30%) than houses (21%). That is about location: many apartments are in city centres with lots of paving and little green, where rain has nowhere to go. Of course, water on the street means something different for a fourth-floor flat than for a ground-floor home or a house with a basement. For an apartment, look mainly at the entrance, the storage rooms and any underground car park.
Elevation matters a lot. Of the homes at least half a metre lower than their surroundings, 71% have an elevated indication.
Flooding: look at both the chance and the depth
With flooding there are two numbers you need to read separately: the chance that water arrives, and how deep it would be.
For the chance we use the local flood probability: the yearly chance that water stands at that spot because of a flood. We call a chance greater than 1 in 300 per year elevated. That applies to 12.5% of the homes for sale in our listings, roughly one in eight. Another 18% fall in the middle class.
The map also shows how deep the water could get in a very unlikely, extreme flood. Almost half of the homes (48%) would stay dry. For 31% the water could reach a metre or more, for 15% two metres or more.
Those two numbers do not move together, which the big cities show nicely:
- In The Hague the chance of a flood is low almost everywhere, because the coast is heavily protected. But if it does go wrong, water would reach a metre or more at 61% of homes.
- Utrecht is the opposite. The chance is elevated for 69% of homes for sale, yet in an extreme flood the water reaches a metre or more at only 14%.
- In Almere the chance is medium almost everywhere, but the city lies so low that 94% of homes would get a metre of water or more in an extreme flood. That is what living in a polder means.
- In Den Bosch and Arnhem an elevated chance and a large depth often do go together.
There is good news too. On the 2050 map, which assumes the dykes will meet the new safety standards by then, the share of homes with an elevated chance drops from 12.5% to 1.9%. In Utrecht, Den Bosch and Arnhem the elevated risk all but disappears. Not along the Maas, though: in Maastricht (15%) and Venlo (29%) the chance stays elevated in 2050.
Thirteen cities side by side
The municipalities with the most homes for sale, plus Maastricht and Venlo for the Maas. Percentages of the homes that were for sale this morning.
| Municipality | Homes | Heavy rain: elevated | Flooding: elevated chance | Stays dry in extreme flood | 1 metre or deeper |
|---|---|---|---|---|---|
| Amsterdam | 3,691 | 28% | 6% | 31% | 18% |
| Rotterdam | 2,744 | 29% | 4% | 11% | 54% |
| The Hague | 2,385 | 25% | 1% | 14% | 61% |
| Utrecht | 1,002 | 19% | 69% | 25% | 14% |
| Groningen | 954 | 26% | 0% | 48% | 26% |
| Eindhoven | 937 | 13% | 0% | 96% | 0% |
| Almere | 870 | 14% | 0% | 2% | 94% |
| Haarlem | 809 | 26% | 0% | 91% | 1% |
| Tilburg | 656 | 17% | 0% | 100% | 0% |
| Arnhem | 582 | 38% | 32% | 47% | 51% |
| Den Bosch | 514 | 21% | 63% | 5% | 63% |
| Maastricht | 508 | 49% | 15% | 62% | 16% |
| Venlo | 404 | 31% | 29% | 72% | 17% |
What stands out: heavy rain is an issue everywhere, including cities with no flood risk at all, such as Tilburg and Eindhoven. Maastricht has the highest share at 49%, which fits a hilly city where rain runs down the slopes to the lowest streets.
Is it reflected in the asking price?
No. We compared each home's asking price per square metre with the median of similar homes (apartment or house) in the same district. Homes with an elevated heavy rain indication ask exactly the same as homes with a low one. The flood chance makes no difference either. Sellers do not price it in, and buyers apparently do not ask them to. If you want to take it into account, you will have to do that yourself.
What to do with it when you buy
An elevated indication is no reason to walk away. It is a reason to look more closely. A few things that help:
- Ask the seller about water. Has there ever been water in the crawl space, basement or shed? Has water come in after a cloudburst? Sellers in the Netherlands must disclose defects they know about.
- Check the threshold at the viewing. Is the front door level with the pavement, or lower? Does the garden slope towards the house? How is it paved, and where does the water from the roof go?
- For an apartment, look at the shared parts. Water in the car park or storage rooms is a matter for the VvE, the owners' association that every Dutch apartment building has. Ask whether there has been damage in recent years.
- Check your insurance. Damage from heavy rain can usually be insured and is often included in a standard buildings and contents policy, but read the terms. A flood caused by the failure of a primary flood defence, such as a dyke along a major river, cannot be insured. For that, after a declared disaster, there is the Disaster Compensation Act (Wts), which covers part of the damage, not all of it.
- Look at the map yourself. Each home page shows both indications for the address. The government website overstroomik.nl (in Dutch) shows for every postcode how high the water could get and whether you should leave or stay indoors.
Read more
- What the foundation risk indication on a listing does and does not tell you
- Buying on a busy road: how much noise, and does it affect the price?
- A checklist for viewing a house
Looking for a home? All homes for sale on Buurtje.nl show the water indications for each address, next to noise and foundations.
