Dyke reinforcements in Northern Meuse Valley:

A special approach has been taken on the dyke reinforcement projects: from the outset, people, companies and other local stakeholders are closely involved in exploration and planning, making a key contribution to reviewing and selecting the possible measures to be taken.

While the rest of the Netherlands has already lived for centuries with dykes, people in Limburg are only just getting used to the idea of them. This is due to the unique landscape; the river Meuse naturally lies lower than its surroundings, slicing into the landscape to create the plateaus of the Meuse, which act as a buffer against flooding. Residents sometimes had to move their household effects upstairs to keep them dry, but they didn't know any different.

The floods in 1993 and 1995 put a different complexion on things, causing major inconvenience and jeopardising safety. Temporary dykes were quickly built in 1996, taking practical action as required, but without any coherent plan behind it.

Initially temporary, these measures were later incorporated in the Dutch Water Act as primary defences, but they no longer meet the standards of today. The water discharge volumes to be expected are only set to increase as the climate changes. It should also no longer be possible for normative high water levels to breach the dykes, as is the case at present.

The Limburg water authority, Waterschap Limburg, is faced with the major challenge of ensuring the basic safety of people living on the Meuse by 2024, sustainably protecting them from rising water levels. This sometimes has profound consequences for residents. The programme is further complicated by the landscape: the Meuse valley does not feature flat polders like in the rest of the Netherlands. Existing dykes are connected to the high land around (known as high ground) or form small links between higher areas. Dyke construction normally involves strengthening existing dykes. In this part of Limburg new connections have to be made to high ground. The works also include introducing new dykes to the landscape, which are sometimes more than twice the length of the existing dyke. It is not dyke reinforcement at issue here, but the introduction of dykes, with a new layer being effectively added to the landscape.

During the reinforcement process the location of existing dykes is scrutinised to ensure they are carefully incorporated at the right position, including for years to come. The emphasis here is not just on improving water safety, but also on strengthening the quality of the region. The choices we make today will shape the landscape for years to come. This is the big difference from the stopgap construction of the temporary dykes in 1996, which were built in the face of urgent need.

On four projects, Baarlo - Hout-Blerick, Thorn - Wessem, Arcen and Well, system measures are also being investigated as dyke relocations or retention areas. The aim here is to find the best combination of measures so that today's choices remain sustainable and cost-efficient in the future as well.

A complication is the fact that buildings are sometimes located very close to the Meuse, with major changes in the landscape. In Arcen for example, many back gardens open virtually onto the Meuse, with just footpaths behind them. These residents have a beautiful view of the river, but the location for the water safety measures runs right through their garden. There are low walls in some places, but they would need to be far higher. Resulting in a substantial change for people, like suddenly having a two or three metre fence outside their back door. The solution here is to combine innovative solutions and customisation. During this process frequent and open communication with residents about solutions and underlying arguments is essential.

It is not only the stakeholders' wishes that are taken into consideration; opportunities to tie in other projects with dyke reinforcement have also been identified. One example is the simultaneous restoration of brooks. The industry-wide 'Approach to Sustainable Civil Engineering' has been applied to sustainably combine dyke reinforcement with projects involving cultural history, water management, ecology and leisure.

This programme lives up to the motto of the Water Authority: 'with the local community, for the local community'. One striking example of this is the unanimous decision of a small group of residents from Kessel (11 homes) living along the smallest dyke in the Netherlands (145 metres): in consultation with the municipality and Waterschap Limburg they chose to forgo strengthening the existing flood defences. With their decision, the residents, whose houses stand on relatively high land, accept they will occasionally be faced with flooding. The programme team is now preparing for the relevant part of the flood defence to be taken out of the Water Act once certain formalities have been completed.

To ensure local support, residents, companies and the authorities are being involved in the planning process as far as possible. The task is clear, but development may differ, therefore offering plenty of scope for stakeholders to contribute their thoughts. The first six months of the programme alone saw some 800 contact moments with the local community, including drop-in evenings, kitchen table discussions and design workshops. According to the motto that it's better to spend time beforehand doing things properly than patching them up afterwards.

The sustainable design principle (SDP) of participatory design has not only provided inspiration but also guidance here. Witteveen+Bos has developed an in-house, evidence-based method to assess levels of support and whether adjustments of the manner of participation are required.

These integrated project teams are an important force behind implementation of the programme, which involves completing fifteen different dyke reinforcement projects in a relatively short period of time: a process of investigation, plan development and preparation for realisation, carried out in consultation with the local community.

This strategy of bundling forces is new to the Netherlands, not only in technical terms as regards innovation, but also the approach to the local community and programme, and the integrated collaboration. Waterschap Limburg is now documenting this knowledge and expertise in a manual, which will allow future projects in Limburg and the rest of the Netherlands to benefit from the innovative methodology and the experiences acquired on the Northern Meuse Valley programme.