Dutch Water Legacy

The landscape before the coast consisted of lakes, rivers and stretches of land. Gradually, the land was reclaimed with the construction of dikes and the use of windmills, making it safer and able to withstand the influence of the water.

The battle against the water is a collective effort. Ever since the first dikes were built in the Netherlands, consultation and collaboration have been used as strategies to realize and maintain this practice. The water boards are the oldest form of democratic governance in the Netherlands, focused on water management and safety. The water boards still exist and have a democratically elected leadership.

Throughout history, major disasters have regularly affected the Netherlands, including violent storms, dike breaches and floods. The St. Elizabeth’s flood in 1421 had a huge impact on western Holland. Currents in the delta changed course as a result of this storm. The dikes and polders had to be partly reconstructed. For centuries, major catastrophes and natural disasters in the Netherlands have led to innovations in water management. The innovations are catastrophe-driven.

For centuries, the battle against the water was fought by means of the manual construction of dikes and the use of windmills. The mills pumped the water from the polders with a scoop wheel or an auger. In this way, lakes could be pumped dry and rainwater was drained from low-lying areas.

In the 17th century, the large cities of Holland grew into modern metropolises. From here, merchants left for destinations all over the world. Amsterdam was an important center of trade and culture, with enormous wealth.

The landscape north of Amsterdam historically consisted of large lakes. These were pumped dry by order of wealthy Amsterdam entrepreneurs. This is how they invested their assets. By means of dikes, canals and windmills, large and deep lakes could be kept dry by dividing them into a number of smaller polders. The windmills were placed one in front of another, in order to drain the polders in stages.

The entrepreneurs who invested in the construction of polders built their country estates there. The fertile soil was ideal for agriculture and stock farming. In this way, a new artificial landscape of utility and pleasure was created. Alkmaar, a city that was once surrounded by water, became the trading center for the sea of green. Nowadays, the age-old cheese market is a major tourist attraction.

The Zuiderzee, an inland sea, is centrally located in the Netherlands. During the flood of 1916, the dikes around the Zuiderzee burst and produced disastrous consequences. After this disaster, an old plan to dam the Zuiderzee was carried out.

The Afsluitdijk (enclosure dam) dates from 1932 and dams off the Zuiderzee from the sea. Thus, a large lake in the heart of the Netherlands was created. The water changed from salty into fresh. The Afsluitdijk created security, freshwater reserves, and the opportunity to create a completely new province on what was the bottom of the Zuiderzee.

The Zuiderzee Works provided for the construction of five large polders, of which four were realized. In this new world, new agricultural villages emerged on an unprecedented scale for the Netherlands. The entire landscape is designed by man. The new satellite city of Almere was built near Amsterdam, and in 40 years’ time it had developed into the country’s fifth-largest city.

Disaster struck again in 1953, when exceptionally high sea levels led to massive dike breaches, almost 2,000 deaths and immense destruction in the coastal provinces. Here again, a solution that had been proposed earlier was put in place: the Delta Works. This system of defense infrastructure physically blocks off the estuaries with strong dikes. This resulted in a considerably shortened coastline and the emergence of inland (mainly freshwater) lakes.

The Delta Works connected islands in the province of Zeeland. New connections emerged along with a new, man-made landscape with opportunties for recreation and tourism. Under pressure from social protest, the dam in the Oosterschelde was turned into an open storm surge barrier that only closes in case of danger. The salt water and tides continue to flow around the barrier during normal times, to the benefit of natural ecosystems.

Besides offering protection against the water, the Delta Works also generated major social, economic, cultural and ecological changes. This is in keeping with the Dutch tradition of making ‘work with work’, or linking tasks and seizing opportunities offered by the interventions. As the project implementation progressed, awareness of natural ecocystem values and sustainability gradually increased.

The Zuiderzee Works and the Delta Works protected the Netherlands against the sea. The next disaster, in 1993, came from the rivers. Climate change and strong urbanization of the water catchment areas of the Dutch rivers produce greater peak loads at high tide. Over a short period of time, large quantities of water flow from Germany, Switzerland, France and Belgium to the Dutch delta. In 1993, disaster was narrowly avoided as the central part of the country was in danger of being flooded by the rivers. A new water plan became an urgent necessity.

‘Room for the River’ was a program to make the rivers safer by giving them more space on land. The river courses were widened and deepened. Inside the dikes, space was created to allow controlled flooding of the rivers in exceptional cases. The program was followed up with further reinforcement of the coast in order to increase flood protection across the country. An important principle of the program was to always link water safety to spatial quality, social issues and economic or ecological improvement – entirely in line with the age-old Dutch tradition.

Improvements in water safety deeply affects the economy and society. Existing cities, monuments, nature values, agriculture, and of course all the residents and stakeholders in an area must be taken into account. Custom planning is required throughout the whole process. For the historic city of Kampen, for example, this means that flood protection is in the hands of a large group of volunteers. In a matter of hours, they can build an emergency flood defense in the city, supported by modern technology, logistics and materials.

A complete menu of innovative reinforcement options for river dikes has been created, whereby the strength of the dikes can be maximized using the minimum amount of space. Each assignment poses very specific questions and challenges, which eventually led to these innovations.

In case of extremely high water levels, the river water can be drained via the Noordwaard polder. The buildings and important infrastructure remain dry, and people and animals can also escape from the polder when the water rises. Whereas in the old days a dike breach spelt disaster, nowadays a fascinating water spectacle emerges.

Increasing water safety has provided the city of Venlo with a new attractive waterfront featuring attractive public squares.

It is only a very small risk (1 in 80 per year), but if the river IJssel ever reaches a critical water level, a complete green river is ready and waiting to drain the water. This dry bed is in use for agriculture, and is always ready to serve as emergency drainage.

‘Room for the River’ and subsequent water safety programs have created numerous linking opportunities for agriculture, recreation, heritage and spatial quality. One of the most visible results is the enormous benefit to nature and ecology in the river area.

Customized solutions for the coast are required to preserve the ocean views from historic seaside resorts and integrate existing buildings while also reinforcing the dunes. A notable innovation is the reinforcement of dunes by concealing concrete dike infrastructure within the natural landscape. Another innovation is the installation of waterproof lining inside the dikes. The shape of the stones used in dam construction can also be optimized to attenuate wave energy.

The sand motor is designed to let nature do the work. Ocean currents drain the sand from the sand motor and deposit it along the coast, reinforcing it in a natural way. Engineers keep a close eye on this process using modern technology and processes.

Katwijk is a historic seaside resort. Dune reinforcement here would obstruct the prized ocean views. The solution was to construct a concealed concrete dike to allow the dunes to meet the new safety requirements while retaining their original height. The dam was developed as a parking garage that creates more space for visitors' cars.

The newest ports areas in Rotterdam are located in the middle of the sea. This reclaimed land offers plenty of space for the largest container ships in the world.

A thousand years of working on water safety has taught us an important lesson: the work is never done. New challenges are posed by climate change, droughts, sea level rise, heat stress in cities and shortages of drinking water. These challenges and the threat of their disasterous effects call for new innovations in water safety. Technical ingenuity will be applied to find practical solutions and link water safety to economic, social, cultural and ecological co-benefits.

The landscape can also be managed using a climate-adaptive approach, which improves water retention capacity and benefits natural ecosystems. Streams which were once channeled and straightened are allowed to assume their original winding courses, making the old landscape visible again.

Climate change (sea level rise, period of unpredictable rainfall and drought, and heat stress) and the energy transition pose urgent challenges that require solutions. Designing green cities improves the living environment and spatial quality of the urban zone. Green roofs, new parks and permeable pavement all play a part in this initiative.

Historically, large stretches of the Dutch coastline were regularly flooded at high tide. These dynamics enabled an exceptionally rich saltmarsh ecosystem to develop and thrive. After dikes were constructed, many former saltmarshes were physically separated from the sea and became severely degraded as a result. Recent projects have helped to restore the saltmarshes through the construction of small artificial dams, in hopes of recovering the majesty and value of the historic coastal ecosystem.

The Dutch approach to living with water has become an important national export product. The idea is not necessarily to implement copies of Dutch delta solutions elsewhere, but to use the knowledge generated by Dutch experts as the basis for appropriate solutions in other areas facing water challenges.