Flood protection

Flooding along the coast can be driven by storm surges and sea level rise. Between 1902 and 2015, the Earth's average sea level rose by 0.16 m. The average annual rise during that period did not stay the same, but accelerated. Meanwhile, the global average (calculated over the period 2006-2015) is 3.6 mm per year. Which corresponds to about 2.5 times the rate as the average rise of 1.4 mm per year between 1901 and 1990 (IPCC 2019). More than 85% of the Belgian and Dutch coastal area (zone up to 10 km inland for flooding from the sea) lies below +5.0 m TAW and thus below the level of an annual storm (+5.5 m TAW) (EEA 2006, Eurosion project, EEA 2013, EEA 2017). About 15% of the area in Flanders is less than 5.0 m above mean sea level. Moreover, the Belgian coastline is the most built-up in Europe. In addition to habitation, the coastal zones of the Netherlands and Belgium host important economic activities, including the presence of seaports. As a result, in case of flooding, the loss of life and material damage can be very high (Publications office of the European Union 2010, Kellens 2011, Boelaert 2017, EEA 2017, Coppens et al. 2018). Without mitigation and adaptation measures, the annual damage from coastal flooding in the EU could increase sharply, to almost 814 billion euro in 2100, with at least 3 million EU citizens affected by coastal flooding (European Commission 2020).

The Coastal Safety Master Plan (2011) includes the measures to be taken for adequate protection of the coastline and adjacent low-lying polders against a storm surge with a return period of 1,000 years with 2050 as the time horizon, taking into account a sea level rise of 0.3 m. The plan has been implemented step by step since it was approved by the Government of Flanders on 10 June 2011 and has already reached an advanced stage. The Coastal Vision project wants to develop a long-term approach for the protection of the Flemish coast.

The mutual cooperation between governments, knowledge institutions, companies and citizens (the so-called Quadruple Helix) plays an important role in the development of innovative concepts, such as nature-based solutions that are becoming more and more important in coastal protection.