Flood protection in the Netherlands

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Map of the Netherlands without dikes with potentially flooded areas

The flood protection in the Netherlands (the Netherlands tegen het water strijd , literally battle against the water called) and has long been of great importance. About 26% of the country's area is below sea level and is therefore acutely threatened by flooding. In the past, countless people lost their lives in flood disasters, of which the Dutch storm flood of 1953 was the last so far.

First efforts and problems from overexploitation

Terps

Terps with church in Hegebeintum , Friesland

Already during the Iron Age around 600 BC. BC people looked for ways to colonize the low-lying coastal areas in today's provinces of Friesland and Groningen with their fertile clay soils . The first inhabitants built a large number of artificial mounds, so-called terps (Dutch terpenes or wierden ), here. Later on, churches were often built in the center of these hills, while farms were usually established in the lower areas around them. Even today, these residential mounds are a typical feature of the landscape on the north Dutch coast.

Levees

Around the year 1000, the embankment of rivers and coastal areas to protect them from flooding began. In the beginning it was mainly peat areas , from the 13th century onwards, more and more dikes were diked. The first dikes were anything but strongly fortified, and storm surges regularly led to dike breakthroughs . Towards the end of the Middle Ages , the dikes were then increasingly reinforced. In addition, based on the Flemish model, the establishment of so-called Waterschappen (Dutch literally "Wasserschaften") and Hoogheemraadschappen (literally "Hochheimratschaft") began. These partly supraregional bodies are still responsible for the administration of water management in the Netherlands.

Peat extraction

From the 11th century , a period of exploitation of extensive peatlands began in the lowlands of Holland and Utrecht , which is known in Dutch as Grote Ontginning (roughly: large reclamation). The agricultural areas in the affected regions initially increased significantly during this period. To drain the peat, ditches were dug that drained , for example, in the Rhine , Lek or Maas . However, the now dry land subsided over time, making it vulnerable to storm surges and other floods. In order to protect the newly reclaimed areas, dikes were built, the maintenance of which was the responsibility of the local farmers and landowners. This area was probably completely diked around 1150, peat extraction continued here until the end of the 13th century.

Creation of lakes through overexploitation

Peat cutting under water, around 1800

With the advent of the so-called baggerbeugel , a kind of landing net with a long handle, in the 16th century the peat could also be extracted below the surface of the water, a practice known as slagturven . The cut peat was then dried on recessed areas, the so-called legakkers . One consequence of slagturvens, especially when it was used on a large scale, was the formation of partly large lakes when the legakkers were flooded by storms. Occasionally, several small lakes could merge into one large body of water after a strong storm. In this way, the Haarlemmermeer and Leidsemeer united in the 16th century , creating a large area of ​​water. It was not until the 19th century that the decision was made to drain them. Further examples of this type of water body are the Loosdrechtschen Plassen and the Vinkeveense Plassen in the north-west of Utrecht .

Large-scale land reclamation

Windmills on the dike of the Overwaard Polder near Kinderdijk

Polders

Towards the end of the Middle Ages, the demand for agricultural land rose sharply in line with the rising population figures, especially around the rapidly growing city of Amsterdam . Therefore, the embankment of large areas, the so-called polders , began, the ground level of which was usually well below the water level of adjacent waters. The water therefore had to be pumped over the dykes from the drainage ditches . For this purpose the windmills typical of the Dutch landscape today were built. The first of these mills was built by Floris van Alkemade and Jan Grietenoon near Alkmaar around 1408 . The first documented drainage of a polder was that of the Achtermeer polder south of Alkmaar. However, it is not certain whether this was actually the first of these projects carried out in what is now the Netherlands.

Today there are more than 3,000 polders of different sizes and ages in the Netherlands, especially in the provinces of Noord-Holland , Zuid-Holland and Flevoland , with the latter being made up entirely of polder areas.

Zuiderzeewerke

The Zuiderzee Works

The Zuiderzeewerke are a system of dykes, pumping stations and reclaimed land in the north of the Netherlands. Its most important structure is the final dike, completed in 1932 . This runs between Den Oever in North Holland and Kornwerderzand in Friesland and separates the former Zuiderzee from the North Sea . The large lake created by the construction is now called the IJsselmeer . The first plans to dike the Zuiderzee date back to the 17th century , but failed for a long time because of the technical feasibility and in later times also because of the resistance of some parts of the population. It was only after the momentous storm surge of 1916 that the plans were finalized under the then Minister of Transport, Cornelis Lely, and construction finally began in 1927.

After the completion of the dike, work began on draining large areas of the former Zuiderzee. In addition to the Wieringermeer polder belonging to North Holland , the majority of this land area today forms the province of Flevoland, which was founded in 1986.

Modern flood protection

In modern times, areas of high economic value and great importance for social peace are generally better protected in the Netherlands. For this, factors such as the monetary value of animals and plants as well as the population density are used; for example, the value of a human life is estimated at € 2.2 million. This procedure has been enshrined in law since the 1950s. In 1996 a new law divided the Netherlands into hundreds of individual dike rings (Dutch: dijkringgebied ) with different levels of protection. These protection levels determined whether an area should be protected against a flood event, as is to be expected once every 500 years. The highest levels were assigned to the areas of the Randstad and provided facilities that should protect against flooding, as statistically occurs once every 10,000 years. With the new law of January 29, 2009, this classification was updated again and adapted to the expected changes due to climate change .

Flood disaster of 1953 and construction of the Delta Works

Flooded areas in the southwest of the Netherlands in 1953
Oosterscheldekering storm surge barrier, part of the Delta Works

On the night of January 31st to February 1st, 1953, the worst North Sea storm surge of the 20th century occurred . During this event, often simply called de ramp (the catastrophe) in the Netherlands , severe flooding occurred along the North Sea coast. In the Netherlands, the delta of the Rhine and Meuse rivers and the Scheldt were particularly hard hit . Almost 2,000 people lost their lives in the Netherlands alone during the disaster.

As a result of the flood disaster, plans arose for the construction of the Delta Works, an ambitious project to protect the western coastline from flooding events like in 1953. The wide inlets in the region were closed and the coastline in the region was shortened considerably. Part of the delta works include the large barrages Oosterscheldekering and Maeslantkering .

Floods on rivers

Along the great Dutch rivers, too, dyke breaks and floods occurred again and again, often due to straightening and canalization, which robbed the rivers of their natural flood areas. Heavy rain upstream or meltwater from the Alps could no longer be collected downstream and regularly flooded inhabited areas. In response to particularly high water levels in 1993 and 1995, a plan to improve flood protection (Dutch: Deltaplan Grote Rivieren ) was initiated for the large rivers in the Netherlands, based on the draft of the Delta Works . Among other things, this provided for a significant reinforcement of the dikes, particularly along the Rhine and Maas.

In addition , an action plan for flood protection on this important waterway was drawn up in 1995 in cooperation with Germany , France , Luxembourg and Switzerland , which also have a share in the Rhine, and implemented by 2005. Among other things, this led to the establishment of networked flood warning centers and forecast systems. The action plan, worth a total of € 4.5 billion, led to a general improvement in flood protection in the affected areas, but it was unable to provide a solution to all problems.

Use of new technologies

In recent years, new technologies for protection against flooding have increasingly been used on the Dutch coasts. A prominent example are flexible flood barriers such as those used in the port of Spakenburg south of Amsterdam. This barrier consists of a 300-meter-long section of 12 cm thick plastic bulkheads , which are normally embedded in the ground. At high tide, the water penetrates through small openings in the harbor basin and pushes the bulkheads upwards, which form a barrier up to 80 cm high. The cost of this construction was around € 6.6 million.

Fortification of the coasts

Hondsbossche Zeewering before the redesign
The redesigned Hondsbossche Zeewering in July 2015

In the course of climate change, researchers expect the sea level in the North Sea to rise by one to four meters within the next 100 years. This means that coastal fortifications and dykes that were previously considered safe no longer offer adequate protection and in some cases would have to be massively increased. For this reason, attempts have recently been made to counteract this by flushing up new beaches on critical stretches of the coast. As of 2014, 35 million m³ of sand were washed up between the North Dutch villages of Petten and Camperduin to create a 300 meter wide beach. As a side effect, a 24 meter high viewing dune, a bathing lagoon and a nature reserve were created here. Before that, this section was protected by the Hondsbossche Zeewering , an unplanted dike originally built in 1792 from basalt blocks. However, this dike was no longer sufficient for the changing environmental conditions and should have been raised by up to four meters. In addition, parts of the village of Petten would have had to be relocated.

Where the seaward reinforcement of the coasts is not easily possible, for example due to strong ocean currents, plans were drawn up to protect the coast further inland. An example of this is the West Zeeuws-Flanders region, in the southern part of the Zeeland province. Here, existing dunes about 300 meters from the coast were reinforced and creeks were dug in the hinterland that drain into the Westerschelde via a tidal channel . In addition to the improved coastal protection, a new local recreation area with habitats for various species of coastal birds was created.

Future developments due to climate change

A low-lying country with long stretches of coast like the Netherlands could be particularly hard hit by climate change in the future. In addition to the rise in sea level, higher discharge volumes are expected, especially on the Rhine and Maas during the winter months and drier summers. A change in the ecosystem and the associated effects on agriculture and tourism are feared. In 2007 the Dutch government had a catalog of measures drawn up to deal with climate change. Among other things, this provides for additional annual investments of € 1.2 to 1.9 billion until 2050 just for adjusting the safety level of existing dikes. Furthermore, the commission recommended relocating dykes on various rivers in order to give them more space for natural expansion and thus to be able to cope with more severe flood events.

Other concepts deal with the design and construction of so-called "floating cities", which are to be built on pontoons and thus could react flexibly to rising water levels.

Dutch expertise abroad

The Dutch people's centuries of experience in flood protection are highly regarded abroad. After the devastating Hurricane Katrina , for example, Dutch companies designed new flood protection concepts for the city of New Orleans in the US state of Louisiana .

Flexible flood barriers based on the Dutch model are now being built in China , Vietnam and the United Kingdom , for example . In 2017, the Netherlands, together with Japan and the United Nations Environment Program, founded the Global Center of Excellence for Climate Adaptation, with the aim of supporting states and regions that are struggling to adapt to changing climatic conditions. Every year the Netherlands export goods worth around € 8 billion in the areas of flood and climate protection.

Individual evidence

  1. Facts & Figures. In: holland.com. Retrieved July 12, 2018 .
  2. The story. In: terpenenwierdenland.nl. Retrieved July 9, 2018 .
  3. Geschiedenis van waterschappen. In: Digitaleetalages.nl. Retrieved July 9, 2018 (Dutch).
  4. De Grote Ontginning Van Middeleeuws Zuid-Holland. In: geschiedenisvanzuidholland.nl/. Retrieved July 10, 2018 (Dutch).
  5. 1530: Het landvernielende slagturven. In: rijnland.net. Retrieved July 10, 2018 (Dutch).
  6. 1477 - 1508: Three have been één Haarlemmermeer. In: rijnland.net/. Retrieved July 10, 2018 (Dutch).
  7. History of Loosdrecht. In: wijdemeren.nl. Retrieved July 10, 2018 (Dutch).
  8. Ruud van Capelleveen: polders Hollandse. In: absolutefacts.nl. Retrieved July 11, 2018 (Dutch).
  9. Menne Kosian: Droogmakerijen. In: landschapinnederland.nl. Rijksdienst voor het Cultureel Erfgoed, July 2017, accessed on 11 July 2018 (Dutch).
  10. Construction of the Zuiderzee Works. In: 100jaarzuiderzeewet.com. Retrieved July 11, 2018 .
  11. Dirk Asendorf: Place for water. In: zeit.de. August 20, 2009. Retrieved August 13, 2018 .
  12. Wet op de waterkering. In: overheid.nl. Retrieved August 13, 2018 (Dutch).
  13. Waterwet. In: overheid.nl. Retrieved August 13, 2018 (Dutch).
  14. January 31, 1953 - Storm surge catastrophe on the North Sea kills over 2,000. In: wdr.de. January 31, 2018, accessed July 11, 2018 .
  15. Welcome to Deltawerke Online. In: deltawerken.com. Retrieved July 11, 2018 .
  16. Deltaplan Grote Rivieren. In: minienm.nl. Ministerie van Verkeer en Waterstaat, Directoraat-Generaal Rijkswaterstaat, February 13, 1995, accessed on July 11, 2018 (Dutch).
  17. Flood Action Plan. In: iksr.org. International Commission for the Protection of the Rhine, accessed on July 12, 2018 .
  18. a b Kerstin Schweighöfer: Dutch creativity in the fight against the floods. In: deutschlandfunk.de. November 8, 2017. Retrieved July 12, 2018 .
  19. Annette Birschel: Netherlands build beaches against climate change. In: welt.de. November 10, 2014, accessed July 12, 2018 .
  20. Hondsbossche en Pettemer Zeewering. In: hoogwaterbeschermingsprogramma.nl. Retrieved July 12, 2018 (Dutch).
  21. Uit de geschiedenis van de Zijpe: de Hondsbossche Zeewering. In: zijpermuseum.nl. January 12, 2002, accessed July 12, 2018 (Dutch).
  22. ^ Hans Marijnis: Nieuwe kust bij Petten kent alleen maar winnaars. In: trouw.nl. November 5, 2014, accessed July 12, 2018 (Dutch).
  23. Een sterke en aantrekkelijke kust in West Zeeland Flanders. In: hoogwaterbeschermingsprogramma.nl. Retrieved July 12, 2018 (Dutch).
  24. Effecten van klimaatverandering in Nederland. In: rivm.nl. Retrieved July 12, 2018 (Dutch).
  25. Andreas Gebbink: VIII. Climate change and flood protection. In: uni-muenster.de/. September 2010, accessed July 12, 2018 .
  26. ^ Nadine Oberhuber: Swimming Dutch. In: faz.net. October 27, 2013, accessed July 12, 2018 .
  27. ^ Ingrid Cobben: Flood protection in the Netherlands: An export hit. In: euronews.com. July 28, 2017. Retrieved July 12, 2018 .
  28. Flood protection technology as a Dutch export hit. In: handelsblatt.com. November 13, 2017. Retrieved July 12, 2018 .