The Tide Has Changed For Dutch Dykes

In 1953, the Netherlands, always vulnerable to flooding, suffered a major natural disaster. The North Sea washed over half a million acres of land and killed over 1,800 people on the south-western coast.

To protect future generations from similar harm, the Dutch government embarked on one of the greatest engineering projects in history. Over the following decades, engineers constructed a flood defence system of dams, sluices, locks, dykes and storm surge barriers. The Delta Works basically shortened the Dutch coast line and turned sea estuaries into freshwater lakes. In 1994, the American Society of Engineers labelled it one of the Seven Wonders of the Modern World, along with structures such as the Channel Tunnel and the Panama Canal.

Today, little over a decade after the Delta Works were finally finished, a group of Dutch civil servants want to punch a few holes in them.

Safety isn’t everything

Earlier this month, a committee comprised of representatives of all involved levels of government presented a report outlining the possible future of the south-western part of the Netherlands, a delta of estuaries, islands and peninsulas connecting several large rivers to the North Sea.

Joost Schrijnen, a managing director with the committee, wants to create a delta that is cleaner, more pleasant and more natural. With all the focus on safety after 1953, Schrijnen said, “ other aspects were neglected.” He now wants to change that. “But without sacrificing safety,” he added.

Opening water locks would allow the tide to return to now stagnant waters, the report stated. This would be a boon to nature, because certain plants and animals, which have all but disappeared since the estuaries were closed off, can return. Deeper into the delta lies a fresh water basin where smelly algae bloom in the summer. Allowing salt water to reach these outer stretches again could improve conditions for residents and holiday-makers. A hole in the Brouwersdam, for example, would allow for tides as high as 50 centimetres. The opening would make an ideal site for a tidal power plant, which is also being considered by the committee.

Schrijnen has even proposed altering the situation in the Eastern Scheldt, where a massive dam stands as a testament to both the powers of engineering and Dutch politics of compromise. In the 1970s, after years of debate, the government decided to build a retractable barrier that is only closed during extreme weather conditions. Since it was finished, in 1986, it has been shut only 24 times. The retractable barrier was built in an attempt to preserve nature, but it has suffered all the same. Sand banks that used to dry up as the tide swept away are slowly being flooded, damaging both nature and recreation there

Wim Kuijken, an official who leads a special committee advising the government on preparing the Netherlands for climate change, has voiced his support of Schrijnen’s plans. “I understand that safety was emphasised after that horrible disaster,” he said. “But I also understand something needs to be done about the ecological consequences. The water quality in the Volkerak, for instance, is so poor it is pretty much useless.”

An example for the Netherlands

The operations in the south-western Delta could serve as a model for the rest of the Netherlands, Kuijken said. Many parts of the country, of which a quarter lies below sea level, struggle to create a pleasant, watery landscape without compromising safety. Security, however, is not the only issue to consider in Dutch water management. The availability of fresh water is also key. “We can only introduce these measures if fresh water supplies have been tended to,” Kuijken said.

Salt water has advanced far in some places, largely because of the constant dredging in the port of Rotterdam. It may improve nature to allow salt water back in the estuaries of the delta now, but the growing shortage of fresh water caused by climate change needs to be taken into account. The problem seems not so much a lack of drinking water as such, but the locations at which it can be found. “We have plenty, but we need more storage capacity,” Kuijken said.

Using less is not much of an option, Schrijnen explained. Water is essential to Dutch business, particularly the agricultural sector. “We have grown so dependent on the availability of fresh water here in the Netherlands that it would be economic suicide change that. Fresh water is the fuel powering our economy.”

Many of the proposed measures are costly, but it seems the Dutch national government is willing to foot the bill. From 2020, cabinet has reserved a billion euros annually to ensure the Netherlands can remain a safe and pleasant place to live despite climate changes. “That figure still stands,” Kuijken said.