Water Safety

The Netherlands and water are inextricably linked. For centuries we Dutch have had a relationship with water that is unique in the world and we are known for our reputation in the field of water management. In addition to land makers and drainers, we are real dike builders. This is important, because the river basins of the Meuse and Rhine come together in the delta located on the North Sea. The Netherlands therefore has 17.691 kilometers of water-retaining dikes that protect us against the water of the river and sea. Without dikes, the Netherlands would be 1/3 smaller than the current contour.

Plan Ooievaar

H+N+S started the office with Plan Ooievaar. Prior to the founding of the office, the founders already made a name for themselves with this spatial plan that won the first Eo Wijers competition in 1985. Plan Ooievaar is based on the hull approach, in which a dichotomy is used: framework and implementation. The framework provides space for slow, natural processes such as sedimentation and erosion within the river system. And to fast processes, such as agriculture, within that framework. This landscape system thinking is also the identity and basis of H+N+S and has been further developed over the past 30 years.

Plan Ooievaar

The plan marked a new generation of regional plans based on water system thinking. Plan Ooievaar proposes a radical design change in relation to the dyke improvement at the time. Instead of the idea that land should be suitable for agriculture as much as possible, there was more room for nature development, the natural system and room for the river. This plan also formed the basis of the 'Room for the River' programme.

Room for the River

More room for the river became the new starting point for the flood protection approach in the river area. With the dual objective: a robust approach to flood risk management and the improvement of spatial quality. This approach was elaborated in the programs 'Room for the River' (2006-2019) and 'Meuse Works' (2005-2017). H+N+S has been involved in the program from the start and contributed to the 'Long-term vision Room for the River' and provided the chairman for the first quality team.

‘Room for the river is one of the most successful government projects in its size, duration, linked results and quality of implementation,’ says Marinke Steenhuis in the essay Het Rijk als rentmeester

The concepts developed by H+N+S in Plan Ooievaar, among others, gave direction to many plans that have been realized in the context of Room for the River. In that plan it was explained how sand and clay extraction in the floodplains could yield natural values ​​and possibilities for water storage, making the river area safer and more ecologically interesting. Ongoing involvement in the river program led to, among other things, the implementation of plans for Kampen - het Reevediep. In this bypass, meadows have been transformed into wet nature, which serve as a high water discharge for the IJssel. H+N+S also worked on Room for the River Nijmegen, where, among other things, a large secondary channel has been constructed that offers extra capacity for water drainage during high water. Dike improvement projects such as Hagestein-Opheusden were also part of the programme.

Even today, river widening, in addition to dyke improvement, is still the starting point in order to be able to anticipate the consequences of climate change.

Flood Protection Program

After Room for the River and the Maas Works, there is now the Flood Protection Program in which Rijkswaterstaat and the Water Boards are working together on the largest dyke improvement operation since the Delta Works. The aim is to have all dikes in order by 2050. This means that before 2050, 1300 km of dikes must be reinforced and 500 weirs, pumping stations and locks improved. H+N+S is currently working on Wolferen-Sprok and Stadsdijken Zwolle as part of the Flood Protection Program.

Stadsdijken Zwolle

High water July 2021

Last summer we were startled by the extremely high water level in the Meuse and the efforts of recent years were put to the test. Ooijen-Wanssum was one of the areas where extra river space had already been realised, the project was completed in December 2020. Here H+N+S has worked on improving flood risk management by creating more room for the river and building new dykes. Two new dike types have been developed for this purpose; the steep edge dike and the high ground dike.

Nieuwe dijktypen

We are pleased that the area development in Ooijen-Wanssum has succeeded and contributed to lowering the water levels on the Maas. During high water, the water was given more space at Ooijen-Wanssum and the water at Venlo was about 30 cm lower as a result. The dikes just held there, with limited damage. A confirmation that the project is working as intended.

Dike Construction

For the Room for the River project, there was already widespread attention for the approach to dyke improvement. It all starts after the high waters of 1993 and 1995. The high waters of that time woke us up. We have to keep working to keep the water under control. The Delta Plan for the Major Rivers was launched in 1995, in which dykes in the river area were strengthened at an accelerated pace.

Position of the Landscape Architect

At that time, dike construction was dominated by a technical approach, the role of the landscape architect was very small. This changed in the mid-1980s. There was an EIA requirement for all dike projects and the role of the landscape architect changed from stylist of the landscape to designer of the route. The Technical Advisory Committee for the Flood Defenses drew up a 'Guide to spatial design – dyke improvement as a design assignment', to which Lodewijk van Nieuwenhuijze from H+N+S also contributed.

H+N+S was involved in various dyke improvement projects from the start. The first project is Afferden-Dreumel. The plan for the 20 km long dike along the Waal arose from the idea that landscape design of dikes is an integral design assignment on the border of civil engineering and landscape architecture. The new 'tailored' dike profile, in which safety and a sturdy appearance come together, will be adopted as the standard profile for many subsequent projects.

Afferden-Dreumel (© Siebe Swart)

Guidelines for spatial quality

The increasing importance of landscape integration and nature development in dike projects is also reflected in the various 'guidelines for spatial quality' that have been drawn up. H+N+S drew up these for the city of Tiel, theNorthern Meuse Valley and Gorinchem-Waardenburg, among others.

The new water thinking

In the last century, the rapid drainage of water and the supply of water from outside the area were central to water shortages. This has shifted to more space for water and a system approach, as we see with Room for the River. A next step has now presented itself; an integral, sustainable approach to the water system 'The new water thinking'. An integrated approach in which synergy is sought between water tasks and challenges such as climate change, agricultural reform and energy transition. System approach is still relevant here. Soil and subsoil form one spatial system with the topsoil, with water as the guiding principle. Based on this philosophy, the plan for the Eternal Source has been elaborated, which won the 11th Eo Wijers competition in 2021.

Eeuwige Bron

Blue Environmental Visions (BOVI)

'The new water thinking' starts with the BOVIs for 2050, which are drawn up by the various water boards. As H+N+S, we were allowed to contribute to the development of 'The new water thinking' by drawing up a strategic plan for BOVI Water Board Vallei en Veluwe. We are also currently working on a BOVI for Wetterskip Fryslan.

BOVI Waterschap Vallei en Veluwe


H+N+S is also involved in flood risk management tasks at an international level. For example, our expertise in the field of water was requested in New Orleans during the Dutch Dialogues (in the aftermath of Hurricane Katrina). We have contributed to a perspective for the city, where flooding is limited by sufficient storage space and where water can be seen and experienced as part of an attractive living environment. In addition, our team was named one of the winners of the Rebuild by Design Competition (in the wake of Hurricane Sandy), a design competition for innovative and actionable proposals to promote the resilience of the affected area and protect against new flooding. Dutch knowledge is used to prepare these places for climate change.

And now?

The increasingly extreme weather scenarios and the recent event in Limburg, among others, emphasize the importance of dyke improvement and river widening. Climate change is making the weather more extreme. We will always have to keep working on our rivers and dykes, with a view to the natural system, spatial quality and integration into the landscape. In addition, both the excess of water and the shortage of water must be served at the same time. It's not just a matter of fighting the water even more. Focusing on integrality is becoming increasingly urgent and linkage opportunities are still underused. Work must be done on a robust and resilient water system. And we are happy to commit ourselves to that.