Some people notice things in my videos that even I don’t, or they ask questions about stuff I had never really given much thought before. The Dutch drainage system is one such topic. Paul James noticed the drains in one of my videos, which prompted Mark Treasure from As Easy As Riding A Bike to write a blog post about them. Emmanuel Marcel Favre Nicolin from Brazil also mentioned how well the Dutch cycle paths are usually drained. Someone else then asked if I could perhaps write a blog post about the Dutch drainage system and well… here it is!
At first I thought I wouldn’t be able to say much about this. After all rain is not unique to the Netherlands and neither is infrastructure. To keep infra usable under wet conditions you need a system to drain your streets and that is true for the entire world. What could be the big deal about the Dutch way to do it? But with the remarks of Mark and Emmanuel in the back of my head, I started to search the internet.
If you are used to hazardous grates directly in your path as a cyclist like many people also in the UK are, then it is a big deal to think about these things. Examples on the internet show that a lot can go wrong as well without good drainage. Such as this video of a flooded Sydney cycle path.
With so many people cycling in the Netherlands and with the average amount of precipitation in their country, the Dutch need a system that keeps the infrastructure dry without endangering all those people cycling. And of course the Dutch have such a system. Key difference to some of the other systems of the world is that the openings for rain water to get into the sewer system are not horizontally in the street surface, but vertically set in the kerbs (curbs of you are not from the UK). As a cyclist you do not have to ride over these openings that way and that makes all the difference. The system is fairly similar all over the Netherlands (and a lot of other countries in Europe) and it has been in use for quite some time. I don’t think the system was invented by the Dutch though. The Dutch drains look too much like the drains of the Paris system that is even older. The only difference to the Paris system is that the Dutch don’t use extra water to flush the gutters. It rains so often in the Netherlands that flushing happens all by itself!
After a study tour of the Netherlands some students of the Northeastern University of Boston explained the system:
Many of the Netherlands cycle tracks are at sidewalk level or an intermediate level. They are pitched down toward the roadway, just like typical sidewalks. Drainage is then handled by roadway catch basins.
Street level cycle tracks separated by a median have their own small catch basins, spaced out along the cycle track to capture runoff from the cycle track and from the sidewalk that is pitched toward it.
Engineers usually place drainage along cycle tracks that have a high curb, just like they would for a normal road. The catch basin grates are usually smaller due to the smaller impermeable areas. When cycle tracks have no curbs or are pitched on sidewalk or intermediate levels then water will flow into the road where the engineers will have taken this impermeable space into account and have appropriately sized catch basins.
Well, there you have it. I couldn’t have said it any other way. It is plain and simple and it works well. But it underlines once again that what makes riding a bicycle pleasant is in the smallest details! You have to get every detail right to get the experience right as well.
To make this post complete, here’s the complimentary video!
Video explaining the drainage system in the Netherlands.