Major dyke reinforcements

The Levvel consortium has been awarded a €550 million contract to strengthen flood defences along the 32km-long Afsluitdijk in the Netherlands.

Rijkswaterstaat – the part of the Dutch Ministry of Infrastructure and the Environment that holds responsibility for the design, construction, management and maintenance of the main infrastructure facilities in the Netherlands – selected the joint venture, which comprises Van Oord Aberdeen Infrastructure Partners, with a 46% stake, Bam PPP PGGM Infrastructure Coöperatie, also with a 46% stake, and RebelValley, with an 8% stake.

The contract is for the design, construction and financing of the project, as well as 25 years of maintenance work.

The Afsluitdijk has been protecting large parts of the Netherlands from flooding since 1932 and is now in need of refurbishment.

The works will include the strengthening of the dyke with innovative concrete elements and the installation of new pumps to expand drainage capacity – at present, the area drains solely through natural flow. Levvel’s discharge solution has been designed to consume as little energy as possible, using pumps only when necessary. The existing monumental Spuisluizen (drainage locks) in Den Oever will remain intact but will be renovated.

Once reinforced, it has been said that the Afsluitdijk will be able to withstand a storm that occurs once in every ten thousand years.

The A7 road will also be made safer by widening the emergency lanes.

Levvel said it paid attention to recreation and ecology during the design process by including the construction of a cycle path along the length of the Afsluitdijk, as well as ecological facilities. The pumps were said to be fish-friendly, and a floodgate of fibre-reinforced plastic will be installed in the river along which fish are known to migrate.

Michèle Blom, director general of Rijkswaterstaat, said, “Levvel has created a smart and robust design that honors the heritage of Lely (the civil engineer and statesman who was responsible for turning the former Zuiderzee into the Ijsselmeer, and for reclaiming a vast area of new land).”

Construction work is expected to start in autumn of 2018 and finish in 2023.