Is the UK able to hold back climate change related flooding?

As we marked the 70th anniversary of the 1953 North Sea flood earlier this year, how can the UK protect itself from rising tides and rivers?
Shoreline Bacton

Author: Jaap Flikweert, Leading Professional Flooding
Image: copyright christaylorphoto.co.uk  

 

On 31 January, the Netherlands marked the 70th anniversary of the 1953 North Sea flood, when 1,836 lives were lost, including ten of my relatives, prompting billions to be spent on the nation’s flood defences. The flood was also the biggest natural disaster to occur in the UK, where 326 lives were lost along with several hundred more at sea.  

Seventy years later, how did the UK react to this terrible event? And moving forward, how can we protect ourselves from rising sea levels and river flooding caused by a warmer, more storm-prone climate?  

The 1953 flood was the result of annual spring tides happening at the same time as a deep pressure system and gale force winds. As a result, the storm surge of 3-5m breached inadequate sea wall defences in 1,200 places and flooded estuaries along the east coast. The disaster brought about the build of a range of sea defences, in the form of walls, dykes, embankments, and a coastal flood warning system. The culmination in 1982 was the Thames Barrier, built to protect the floodplain upon which much of Greater London is built.  

The coastal defences, which have prevented a repetition of a 1953-scale flood, are coming to the end of their life, putting at risk homes and infrastructure built nearby since the 1960s. 

Some important decisions on protecting our communities from sea level rise and coastal erosion need to be made. The difference between the UK and Netherlands is that Dutch politicians consider flooding as an existential threat to the nation given that 60 percent of the country is at risk. In the UK it’s around 15 percent with lower funding to match. Cost is only one concern though. 

Is it comfortable for people to live behind big defences? How will nature be affected?  

In the case of the UK there is no single silver bullet – only sensible trade-offs between cost, benefits, impact, and risk. For example, building ever higher barriers may not always be the sensible thing to do as we cannot calculate with complete accuracy what the future holds. Even the best computer models available are unreliable as now we lack sufficient data points on which to base precise predictions.  

These compromises came to light in North Norfolk, where building hard sea defences to protect the Bacton Gas Terminal and several coastal villages was considered unacceptable – the problem of coastal erosion would only move further down the coast. 

This tricky problem was solved through innovation, inspired by the Dutch Zandmotor project. This meant creating a new 6-kilometre-long, 7-metre-high beach – comparable to a Wembley Stadium full of sand – to protect the Terminal and feed the villages’ beaches. This £22 million sandscaping project allowed a 20-30 year reprieve. Enough time for politicians, townsfolk, and planners to make choices about the future of the communities. It also saved the Gas Terminal which provides around one-third of the UK’s gas supply. 

Nature-based defences 

Barriers, floodgates, flood warning systems, and community awareness, all have a role when considering flood management. Possibly less well known are nature-based solutions. For instance, when it comes to river flooding, by promoting wetland habitats up-river, it’s possible to solve several issues at once by dispersing and slowing the flow of water while also improving biodiversity.   

A different nature-based solution is to introduce beavers. Their building of dams and canals, reduces the speed of flowing water and increases populations of fish, amphibians, and other wildlife.  

A study by Exeter University into beavers living in the River Otter in East Devon, reported a family of beavers constructing six dams upstream of the flood-prone village of East Budleigh. The beaver dams slowed the flow and lowered water levels through the village during peak flood events.  

Though some may question the value of nature-based solutions during a major flood event, their role in alleviating annual river flooding should not be underrated.  

Coalition of the willing 

Whether the approach is considering sand, beavers or walls, flood defences work best when there is a willing team focused on the problem and looking for opportunities. The best results happen when national agencies, local authorities, at-risk communities, landowners, conservation groups, and businesses work in close cooperation. By focusing on the problem, understanding various needs and business models, it’s easier to design a solution which delivers many benefits while fulfilling different agendas. It is also the best approach to attract multiple funding sources. 

Going Dutch 

Despite what some believe, the UK has a strong system for managing flood risk. But it should take advantage of innovations already tried and tested by the Dutch. This only works if these innovations are adapted to the local setting. These innovations include sandscaping, the development of new software tools, methods for partnering, high performance sluice gates: all innovative techniques proven on real-life projects.  

A sea defence technique, developed at a cost of more than €10 million to protect the Dutch coast from 1:10,000 per year storms, is in use at Stolford in Somerset. It takes away the need for high, expensive, and unsightly rock defences by making use of a field of champagne cork-shaped concrete blocks placed on the seaward side of an embankment. Storm waves flow over the structure and enter a network of cavities between the blocks that soak up wave energy. The high-density concrete blocks are constructed to move slightly, keeping the structure in place solely through weight and friction. Walking along the beach it is almost invisible. 

Although benefiting from Dutch ingenuity, flood management remains a particularly complex issue. It demands expertise, engineering, and sound judgement. What defines it most are the political, financial, and social considerations. Floods like the North Sea flood of 1953 grabbed the national psyche. It focused minds.  

As we reach some sort of acceptance level on the effects of climate change, tough decisions will have to be made where to draw the line, especially in relation to coastal flooding and erosion. It is positive to see government support the development of plans to help communities adapt to coastal change, with relocation inland one option. The question that rises will be what is practical to defend and what isn’t? Finding the answer requires level heads and more than a dose of courage. 

Jaap Flikweert is an expert in flooding and coastal management, with experience in designing policies, flood resiliency strategies and implementing innovative flood defences. He led the team that built the sand-based defences which saved Norfolk’s Bacton Gas Terminal, advised the US government following Hurricane Katrina and informed the Dutch government on its long-term strategy.  

This article was originally published in Water Magazine on 03 March 2023.  

Do you want to know more or do you have a question?  - Contact our experts on Climate Resilience

Do you want to know more or do you have a question?

Contact our experts on Climate Resilience