The Decay of Amsterdam’s Quays

Amsterdam has around 900 km (560 mi) quays and water borders, of which around 300 km (186 mi) are owned by third parties, who are responsible for their maintenance and the associated costs. The City of Amsterdam itself is responsible for the maintenance of 1800 bridges and 600 km (373 mi) of quays.

Oude­zijds Voorburg­wal with temporary quay support wall and sheet piling (July 2019).

In the coming years at least 850 bridges and 200 km (124 mi) of quay need to be taken care of, most of them supported by wooden piles and many within the historical inner city. Around 50 km (31 mi) is in bad condition already. This is a big and complex job, which will probably take many decades to finish. The whole operation will cost a conser­vatively estimated 5 billion Euros (6 billion US Dollars).

Heren­gracht with temporary quay support wall and sheet piling (June 2020).

Old Quays & Modern Traffic

Most canals in Amsterdam are quite old, some are from the 16th or 17th century. The same holds true for the quays surrounding them. The old canal walls and bridges were built on wooden poles (like everything else built in Amsterdam’s soggy terrain, piles are needed as a foundation). When they were constructed, most traffic consisted of carts and horse drawn carriages. They were never meant to endure today’s heavy vehicles and constant weight and vibrations.

Orange: Construction probably not heeding the legal requirements.
Red: Measures taken because of imminent risk of collapse. (2019)

Around one hundred quays (17 km – 10.5 mi) have been marked as having a high risk of collapsing. The wooden poles on which the bridges and quays rest, once thought to be perfectly conserved when under water, now seem susceptible to a bacteria which eats away at them and causes them to rot. Some bridges have even been classified as barely being able to support their own weight, let alone the current heavy traffic and trams weighing around 40 tons.

It’s All Going Down

The soggy peat and clay layers below Amsterdam (and the Western half of the Nether­lands) mean that every­thing is sub­siding with the terrain, not just houses, bridges and quays, but also roads, railways, tram rails, sewers, cables and gas and water pipes. The polders around Amsterdam subside even faster, which makes it necessary to continuously lower the ground­water level. Causing the drying peat to subside even quicker, and so on. We’re pumping harder these days to keep our feet dry.

Schematic overview of the foundation of the Amsterdam canal quays. Heavy weight (cars and containers along the canal edges, for example) and heavy trucks passing can slowly push out the quay walls towards the canal side, make the wooden poles bend and even break. Eccessive motorized boat traffic can also erode the soil between the foundation poles, weakening the structure.

Politics & Delays

For decades quays and bridges were only repaired when they threatened to collapse. From the 1980s on many city councils neatly avoided this costly hot potato, creating a huge backlog of deferred maintenance. Even though the dangers had been made clear many times, the politicians just held their breath, hoped for the best and spent the money on sexier projects. From 2019 on the city is finally doing much more research and active monitoring of quay deformations, estimating the risk of damages to the buildings next to the quays — imposing more and more restrictions to heavy traffic in the weaker areas to prolong the quays’ expected lifetime.

Ruptured quay at the Nassau­kade because of a burst water pipe (March 2018).

While Amsterdam has maintenance responsibilities, it is also (like all cities) limited in its means, as only around 10% of all income is generated by local taxes. The state has to make sure that cities have enough cash to do what they need to do — yet there is only around 16 billion Euros ($ 19 billion) available for all communities yearly. So as with all administrative problems like this, it is hard to ascertain who bears responsibility where and when exactly. The result is that all parties hide behind this slow process and the city is always short of cash for emergencies like this one.

Additional measures

Many canals in the inner city have already had to be fortified with temporary sheet piling along the walls. Earlier there had been problems on the Lelie­gracht and near the Entrepot Dock. When 30 meters of the Grimburg­wal (from 1870) collapsed in September 2020, suddenly everybody noticed that something needs to be done soon. Changes to the way of working may be needed to lessen the load on the historic quays and bridges, like transporting construction materials and collected waste by boat. Various innovative methods of quay renovation are being investigated.

Collapsed quay on the Grimburg­wal (September 2020).

Videos

Making historic quay walls future proof (EN only)