Engineering Prospects: North-European Enclosure Dam & High Speed Rail

Sea Dam For The North Sea – Is There A NEED?

Proposals for a North-European Enclosure Dam (NEED) that will enclose the North Sea have been outlined. The planned dam walls would protect around 25 million Europeans and important economic areas against rising sea levels over the coming centuries. It has been proposed by the Royal Netherlands Institute for Sea Research, which is the Netherlands national oceanographic institute.

The mega-infrastructure plan to dam entire North Sea has been proposed by one Dutch government scientist to protect against rising sea levels. Sea levels are rising faster than initially predicted and could increase by around one to two metres, above existing sea levels, in the next 80 years if greenhouse gas emissions are not significantly reduced. The Netherlands is one European country that is particularly at risk to the sea level rise. Around a third of the largely flat country exists below sea level. There are huge sea defences, including dams and storm surge barriers, that currently protect the country.

The proposals for the North-European Enclosure Dam (NEED) would see two massive two sea dams constructed. They would consist of a smaller dam that would be around 161 kilometres (100 miles) long. This dam would block the entire western end of the English Channel and would connect Brittany, France to Cornwall in United Kingdom. A northerly dam would be three times as long at around 475 kilometres (300 miles) long. This dam would be in the northern part of the North Sea and would join Scotland, running south of the Shetland and Orkney islands, to Norway. A consequence of the engineering would mean that the Baltic Sea would lose direct access to the rest of the world’s oceans and much of the North Sea would be isolated from the Atlantic Ocean. The North Sea would effectively become a vast lake rather than a tidal sea. There would be a huge impact on the ecosystems of the North Sea. Costs are estimated to be around €250-500bn, or around 0.1 per cent of the gross national product of all the European countries that would be protected.

The engineering for the two dams seems to be feasible with the maximum depth of the North Sea between France and England is scarcely one hundred metres. For the northern dam, the average depth between Scotland and Norway is 127 metres with a maximum depth of 321 metres off the coast of Norway. Fixed platforms can now be constructed in water depths exceeding 500 metres.

The costs and the environmental and economic consequences of such a dam are vast. The cost of doing nothing about climate change and the consequent sea level rise will ultimately be many times higher than the estimates of construction. This dam highlights the consequences of rising sea levels. A sea level rise of 10 metres by the year 2500 is shown as one of the bleakest scenarios. Details of the dams are on the Royal Netherlands Institute for Sea Research (NIOZ) Web Site in both Dutch and English. There are also further details on this link.

Whilst there may not be a current need for North-European Enclosure Dam (NEED), when sea levels rise then engineering solutions such as the two dams would protect many millions of people and cities around the North Sea. The concept shows us one way to protect against sea level rises and how to prevent floods.

UK High-Speed Rail (HS2)

The UK government has given the go ahead for a major high-speed modern railway line linking northern England with the south in London. HS2, as the project is known, is a new high-speed railway line which links the cities of London and Birmingham (in the midlands), with the two northern cities of Manchester and Leeds. The route is also referred to as the Y network since it is roughly in the shape of the letter Y. Construction is divided into two phases with phase two having two parts: phase 1 London to Birmingham, phase 2a Birmingham to Manchester and phase 2b Birmingham to Leeds.

The HS2 network will greatly reduce journey times between cities, free up capacity on existing railways (which have reached capacity) and create economic benefits. Thousands of jobs will be created as a result of the project. Capacity will be tripled with many more trains operating across the entire route. The new railway would carry high-speed trains that are 400m-long with up to 1,100 seats. The line would enable trains to run as often as 14 times an hour in each direction. The line will be high-speed with trains travelling at speeds up to 402 kilometres per hour (250 miles per hour). The first phase of the route is due to be opened in 2028-2031 for the London – Birmingham section. The second phase to Manchester and Leeds is likely to open between 2035 and 2040.

The new railway has been controversial as the route will cut through many protected areas that includes several ancient woodlands. Ancient woodland is one of the rarest habitats in the country and is irreplaceable. These woodlands account for just 2.4 per cent of land in the UK. They are highly complex ecological communities that have developed over centuries. Many properties will need to be destroyed in order to build the new route. To mitigate some of the impacts there are long tunnels, such as in London and through the Chiltern Hills, a scenic area of countryside, north of London.

There are 61 ancient woods along the HS2 route are earmarked for total or partial destruction, whilst an additional 47 will suffer damage from noise, vibration, light and pollution. The UK Woodland Trust has objected to the route’s impact on the ancient woods that are irreplaceable. The Woodland Trust has been campaigning to protect ancient woodlands from HS2 for 10 years. The charity has helped to save ancient woodlands and trees. They have proposals for saving some significant areas of ancient woodland:

  • South Cubbington Wood on Phase 1 could have been saved if HS2 had constructed a bored tunnel underneath it instead of the deep cutting they intend to construct, which destroys 2 hectares of this irreplaceable habitat and severs part of the woodland from the remaining woodland block, which will cause further indirect deterioration of the remaining habitat
  • Whitmore Wood on Phase 2a – a tunnel here could have saved 5.5 hectares of irreplaceable ancient woodland as well as providing additional benefits to other stakeholders in the area, such as local farmers whose farms are being cut in two. This is currently the single biggest loss of ancient woodland on the whole scheme. However, the Phase 2a Committee decided that the additional cost was too high and dismissed the proposed tunnel
  • Nor Wood on Phase 2b is an ancient woodland and local wildlife site. Over 4 hectares of ancient woodland, known to be home to bats, otters and numerous bird species, is to be lost to the line. This area could be protected by tunnelling or the line being moved to avoid it.

Translocation of ancient woodlands have been proposed by HS2. Translocation is an unproven technique and it is unclear if full biodiversity of ancient woodland ecosystems would be preserved. These details have been highlighted from the Stop HS2 web site.

HS2 will offer environmental benefits, as well as economic benefits, of long-distance high-speed travel that links city centres. The railway will provide an alternative to flying to Scotland too. There is an environmental cost from the construction of the project, however, and this includes loss of rare ancient woodlands and property. It will also disrupt some communities along its route.


The two infrastructure projects discussed here, the North-European Enclosure Dam and the UK’s new high-speed railway (HS2), illustrate a need to have infrastructure to help with climate changes. The two projects also show that the developments are rarely perfect from an environmental impact perspective. A different route or a route with an extra tunnel may have mitigated some of the impacts to ancient woodland areas. The NEED concept would have a major impact on sediments, tide and the saline water in the North Sea. This would be a huge impact but would protect millions of people in several European cities.

About mappedit

Geographical practitioner with an interest in climate change, open mapping, sustainability, the transition movement, transport and many other things.
This entry was posted in Cities, Climate Change, Europe, flood, Netherlands, railways, Storm Surge, Sustainable Development, Sustainable Transport, Technology, Transport and tagged , , . Bookmark the permalink.

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