Wietse van de Lageweg

The narrow strip of beach and dunes form an important part of the coastal protection system around the world. Even though it only makes up about 4% of the earths total landmass. They protect the hinterland from flooding, provide freshwater filtration and storage services and add unique wetlands and landscapes which provide many touristic and recreational functions. However, these areas are experiencing heavier erosion each year. Therefore, innovative measures created by the Building with Nature and Living Shorelines philosophies will be put to use in order to halt and reverse ongoing erosion.

This project approaches the development of flood protection strategies as a spatial issue, investigating linking area assignments, application of levee concepts based on Building with Nature (BmN), and developing public support for major landscape changes, through four research questions focusing on:

Behind the research facility of NIOZ in Yerseke lie 12 concrete basins that are flooded during high tide and easy to reach during low tide. Within these basins experiments are performed on how biodiversity can be enhanced on subtidal, hard structures like dikes or pillars of wind farms. To meet current safety standards dikes need to be reinforced. In subtidal parts this is usually done through adding a layer of rock material or steel slag (a waste product of the steel industry with a high density). These reinforcements are often applied in soft sediment areas or on dikes with a high nature value. These locations often receive special protection due to their high natural value. The hard structures provide shelter for the European lobster and other important target species. Dike reinforcements can only take place when this natural value is preserved or compensated.

Sea level rise puts pressure on the safety, ecology and economy of the coast and delta waters. The traditional response from the manager is then to reinforce flood defences. History has shown that this is effective, only it is often a costly operation, takes up a lot of space and only serves water safety. Innovations in coastal management are necessary and urgent to develop new concepts for the levee zone that provide flood safety, increase spatial quality (creating valuable nature and other societal benefits) and give substance to climate-neutral and circular operations. This challenge is already in play in the near future because the new water safety assessment requires a substantial reinforcement task for the dykes of the Western and Eastern Scheldt to be realised by 2050. BwN solutions offer a promising action perspective for our handling of sea level rise, but require more research for optimal incorporation on a large scale.

Biodiversity loss and the need for climate adaptation are major global challenges, according to the World Economic Forum. This also applies to the Dutch national government and, in particular, to the management of the Netherlands' large waters. A number of implementation programmes are already running for the large waters to sufficiently meet European obligations (Water Framework Directive, Natura2000). Recently, the national programme 'Programmatic Approach to Large Waters' (PAGW) was also launched, giving an additional impetus (~2 billion) to restoring the ecological resilience of national waters. The Ecological Resilience 2.0 project is in line with this.

In the Western Scheldt, current velocities have increased especially in recent years due to previous deepening and continuous dredging to maintain the channel for vessel traffic. In general, low-dynamic intertidal areas are richer in benthic life because here the current velocity is lower and the sediment more stable, which is important for the occurrence of various benthic animals.

The 'Working with Water Landscapes' initiative should start connecting the regional economy and the natural dynamics of large waters and surrounding areas. For biodiversity, it is important to consider land and water nature in conjunction. At the same time, those productive and diverse ecosystems add value to the people who live and work around large waters. Working with water landscapes gives entrepreneurs and (nature) site managers the chance to get their ideas and suggestions into handouts for public parties. The working method is different because economic (co-) use takes centre stage instead of public tasks (e.g. water storage, biodiversity or climate adaptation). According to the project group, this will increase support for working towards a shared future.