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Three local municipalities have decided to assess the best way to protect the North Coast of Zealand in Denmark. COWI, NIRAS, DHI and Hasløv & Kjærsgaard will analyze the best solutions for an upgraded coastal protection.
Halsnæs, Gribskov and Helsingør - three local municipalities of North Zealand in Denmark - have decided to step up the coastal protection in order to protect the hinterland and beaches from further erosion.
Consequently, they have asked COWI, NIRAS, DHI and Hasløv & Kjærsgaard to prepare a feasibility study for the future coastal protection between the towns of Hundested and Helsingør.
Particular the storm Bodil that hit the North Coast on 6 December 2013 created an extraordinarily high water level causing extensive damage to existing coastal protection and cliff slopes leading down to it and has emphasised the need for an improved coastal protection.
"Bodil caused a deterioration in conditions along the North Coast and acted as a wake-up call. The damage was so great because structures intended to protect the coast are in many cases worn down and poorly maintained," explains coast specialist Christian Helledie from COWI.
Beaches have gradually disappeared in several places along the North Coast due to the erosion that takes place not only at cliff slopes and beaches but also below the water in the littoral zone. Water depths gradually increase in front of existing coastal protection structures and leads to extensive coastal damage during storms such as Bodil.
The purpose of the feasibility study is to collate experiences from earlier studies and give councillors in the three municipalities a basis on which to decide how regional coastal protection, with beach nourishment as an essential element, can be achieved. The coastal protection requirements will be evaluated for a 25 year and a 50 year period.
Beach nourishment on this scale has not previously been carried out in Denmark except on the West Coast where the Danish Coastal Authority is responsible for the task.
"Beach nourishment for the North Coast has been discussed for decades. It is a pioneering and very positive development, that after so many years, active cooperation is now in place to determine the best solution for coastal protection," says Christian Helledie.
Beach nourishment is not stationary. The sediment, gravel and sand, is transported downstream towards east as a result of the predominant waves from westerly directions. Nourishment protects by raising the beach level, thus lowering the water depth and increasing the distance between the sea and the cliff slopes. Waves reaching the back of the beach is hereby reduced.
The project will also evaluate whether the "natural sediment transport cycle" along the coast can be restored by removing material from near harbours (where it tends to accumulate) and using it for maintenance beach nourishment.
Christian HelledieLead Coastal SpecialistTel.: +45 5640 email@example.com
The study covers: