Dredging for Adaptation to Climate Change in the Netherlands
Type:
Presented during:
WODCON XIX: "Dredging makes the World a better place" - 2010, Beijing, China
Authors:
Pol Hakstege, Anske van der Laan
Abstract: The Netherlands is lowland, situated in the delta of the rivers Rhine and Meuse at the coast of the North Sea. If there were no dikes about 65 percent would be flooded. The threat comes both from high water levels at sea and from the rivers. The flood risks have increased by land subsidence mainly due to human activities and will increase even more due to the effects of climate change: sea level rise, higher discharges in the rivers and increase of droughts. In 2008 the “Delta Committee” came up with measures how to cope with extreme conditions in the future. Not only enforcement of dikes but also other far-reaching measures are necessary. Dredging is an indispensable tool to realise this Delta Programme.
To anticipate on sea level rise the volume of beach nourishment to strengthen the coast will be quadrupled to about 50 million cubic meters per year. It is realised that valuable ecosystems should not be jeopardised by these massive dredging operations. The concept of ‘’Building with nature’’ means that both placement and mining of sand will be done in line with natural processes. A pilot project to test this new approach is the so-called sand engine.
Flood management programmes for the rivers Rhine and Meuse are already in full progress.
These programmes aim to lower the flood levels by providing the rivers with more space for the discharge of water. Extensive dredging operations are taking place for example by creating secondary channels or by lowering the river floodplains. Where feasible the objective of safety against flooding is combined with other objectives such as environmental enhancement, navigation, nature development, and mining of sand and gravel.
The realisation of the Delta programme to protect the Netherlands against flooding in the future means an enormous challenge for the dredging industry not only because of the huge volumes involved, but also because of necessary innovative approaches.
Keywords: building with nature, deltas, flood management, coastal protection, remediation