According to a newly published subsidence map by the Netherlands Center for Geodesy and Geo-informatics (NCG), the country is sinking faster than previously thought. The sinking ground could mean billions of euros worth of damage for Dutch cities and rural areas.
Whilst many will not have noticed the subsidence in the Netherlands, for some Dutch cities and other areas, Groningen and the west of the country in particular, the consequences could not be more striking. Gouda is just one of the cities suffering from a sinking ground. The South-Holland city is built on soil that contains clay and peat.
The inner city of Gouda especially is suffering the consequences of subsidence. Each year, the ground sinks by three millimetres on average. In some places, it even sinks as much as 10 millimetres. Alderman in Gouda, Hilde Niezen, acknowledges that subsidence is a huge problem saying, “Subsidence is something that has been going on for a long time, particularly in the west of the country. But now we are really reaching the limit.”
The results of subsidence can be seen in the subsided facades, cracked walls of buildings, uneven doorsteps, damage to the roads and sewage system, and flooding in houses. According to Niezen, “Everywhere something is sinking. If it's not the roads, it is the parks.”
The unexpected rate of subsidence is particularly down to the dry summers, along with agriculture, salt extraction and the extraction of natural gas. The resulting damages are estimated at 22 billion euros in 2050, for a large part due to the repairs to the foundations of buildings which will be needed. Additionally, it is not just visible damage which is being caused by subsidence; the sinking ground is also causing large emissions of CO2 due to oxidisation of peat.
Unfortunately, there is neither an instant solution nor a single one to the subsidence problem. Niezen reports that some municipalities are trying creative ways to raise the ground, such as using polystyrene or lava stone, basically anything that weighs less than sand.
She expresses that there is a question of whether we need to create supports for all public spaces, noting that, in Woerden, the city is in the process of supporting all streets with piles. In rural areas, other solutions are more appropriate. One thing is certain; doing nothing is not an option.