Afsluitdijk a New Icon of Dutch Flood Protection

Dutch government revealed its master plan for a complete reinforcement of the 32 km long closure dam the Afsluitdijk, the Netherlands

The master plan also includes the construction of a 5 km long artificial fish migration rivier and the construction of a new pumping station. With a capacity of 400 m3/s, the station will be the biggest in Europa.

The project is expected to start in 2017 and has been budgeted for 850 million euro.

Basic requirements

The master plan Nieuwe Afsluitdijk does not specify construction details of the new dam. It only gives the basic requirements and shows drawings of the envisioned new look ( see impression above ). In a later phase, the final design will be determined by the government in close consultation with the contractor.

This creates space for innovation and cost-effective solutions.

Overflow-resistant dam

The Dutch government opts not to raise the dam but to reconstruct it as an overflow-resistant dam. The final design has to meet the safety standards of 1:10.000 years and 10 l/s/m.

This implies the strengthened dam must be able to withstand the waves of an extreme storm that can - theoretically - occur only once in 10.000 years. The waves are allowed to overtop the dams to the extend of 10 liter per second per meter.

Based on an expected sea level rise of 31 cm, the reinforced dam will meet the new flood safety standards until at least 2050.

New construction to break roll-up waves

Limiting the amount of water overflowing the dam, is possible by roughening the cladding on the outer slope. For instance by using energy absorbing concrete blocks or a special designed open structure that can be filled with clay, sand and shells.

Different types of cladding are currently being investigated.

Additional pump capacity

The Afsluitdijk fulfils a key role in the water level management of the IJssel Lake. Discharge sluices at both ends of the dam allow to drain water during low tide at the Wadden Sea.

Due to the expected sea level rise, the discharge capacity of these sluices will decrease. Therefore a additional pumping station will be built.

The new pumping station will have an initial capacity of 400 m3/s. This allows enough discharge capacity during high tide on the Wadden Sea, till 2050.

The new pumping station will be the biggest in Europe. Its capacity will surpass the current record-holder at Katwijk, also in the Netherlands. The biggest pumping in the world is located in New Orleans with a capacity of 567 m3/s.

Source: Dutch Water Sector

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Taxonomy

• Flood Management
• Solutions
• Dams