Guardians of the Thames: the past, present and future of the Thames Barrier

The Thames Barrier celebrated its 40th anniversary recently.

To mark the day, on 7 May, esteemed speakers and experts gathered at One Great George Street in London to explore the past, present and future of the Thames Barrier.

The barrier, which spans 520 metres across the River Thames, protects 125 square kilometres of central London from flooding caused by tidal surges.

That amounts to 420,000 properties at risk, 25 mainline and 54 underground and DLR stations, 226 schools, 13 hospitals, 15 fire stations, 15 police stations and 1.4 million people who live and work below average high tide.

That’s roughly £321billion in capital value of assets.

Flood resilience is becoming an increasingly critical issue in modern urban planning, particularly for major cities like London.

Climate change increases these risks, leading to more frequent and severe weather events, rising sea levels, and increased river discharge.

Flood resilience is crucial.

The 8th wonder

ICE Trustee Richard Bayfield, who opened the event alongside ICE President Prof Anusha Shah, shared:

“When the late Queen Elizabeth II opened the barrier 40 years ago, she used the phrase: ‘it had indeed been a race against the tide and could be described as one of the engineering wonders of the world’.

“Many others have subsequently described the Thames Barrier as the 8th wonder of the world and of course the race against the tide continues.

“The ICE and its membership continues to be at the forefront of this race.”

The design of the Thames Barrier was led by engineering consultancy Rendel, Palmer and Tritton.

Established in the mid-19th century, this firm played a critical role in several significant infrastructure projects, and their expertise was instrumental in the development of the barrier.

Charles Draper, one of Rendel Palmer and Tritton's engineers, conceived the innovative rising sector gate design, which became the hallmark of the barrier’s navigation openings.

This design not only simplified operations but also enhanced reliability, marking a significant achievement in modern civil engineering.

Past

Rory O’Grady, Thames Barrier civil engineer and author, took us on a fascinating journey through time.

The Thames Barrier project faced significant hurdles before construction began in 1974.

It was a long battle for approval following a tidal surge in 1953, as stakeholders needed to be convinced of the need for the barrier, O’Grady told attendees.

Engineers faced a variety of challenges, like overcoming industrial unrest, solving major technical problems and finding the best innovators and manufacturers for the job.

The barrier’s bold, revolutionary design required the expertise of some of the best engineering minds and demanded exceptional craftsmanship.

With each new barrier installed, engineers faced design and operational challenges, such as:

• deeper water
• higher currents
• bigger waves
• access for larger ships
• improving gate and lock technologies
• climate change

After walking the audience through the barrier’s history, O’Grady reflected on the audience’s reaction.

He said: “One of the highlights was witnessing the astonishment of the younger audience members when they learned about the rudimentary state of IT and the scarcity of women in the industry at that time.

“It was incredibly inspiring to see how the achievements of the past continue to resonate with and educate the next generation.”

Present

Andy Batchelor shed light on the power of collaboration in flood defence.

As well as Thames Tidal defences/operations manager, Batchelor is co-founder of I-Storm, a global group of experts who work on barriers protecting against storm surges.

Batchelor emphasised the crucial role of networking with other cities to foster international cooperation and knowledge exchange.

“We should never stop learning,” Batchelor said.

“Whether we have 40 years’ experience of operations like the Thames Barrier or are [just starting out], by sharing knowledge in an open and non-judgemental way we can continue to ensure our systems achieve maximum reliability and operational readiness.”

Batchelor noted that the winter of 2013-2014 was their busiest time ever.

During this period, the Thames experienced its highest tide since the barrier's construction. It had to close 50 times over 13 weeks.

As a result of the barrier's effective operation, no properties in London were flooded. And with great care, the barrier still remains strong.

But the 40th anniversary of the barrier also marks the Batchelor’s final day as manager, stepping down after 25 years in the role.

Future

The Environment Agency’s Laura Littleton offered a glimpse into the future of flood defence in London, with a vision of a resilient Thames Estuary.

She told us about the Thames Estuary 2100 Plan, which looks to manage current and future flood risks in the estuary.

As Thames Estuary 2100 manager, Laura and her team are in charge of making sure London and the estuary are protected from floods well into the next century.

Their strategy, published in 2012, was the first to focus on climate change.

We need to plan for wetter winters, bigger storms, hotter summers, and of course, increasing sea levels and flood risk.

She underscored the importance of proactive measures and adaptive strategies in the face of evolving climate challenges.

For example, raising all flood defences east of the barrier in Kent and Essex by half a meter to prevent flooding from higher water levels.

As sea levels rise, the barrier will need to close more often to protect against storm surges.

By 2050, raising the defences west of the barrier will help reduce these closures and extend the barrier's lifespan.

Another half-meter increase will be needed in the latter half of the century.

The barrier will continue to operate effectively until 2070, which is when, based on current sea level rise projections, the current barrier could be overtopped.

There will need to be a replacement option ready to go from then, which can protect us from higher storm surges.

Looking forward to a brighter future

On marking the structure’s 40th anniversary, Prof Shah said: "This event celebrated the striking landmark, its pivotal role in safeguarding London, people and the amazing infrastructure the city depends on.”

“Honouring the rich history of the barrier, we also looked forward to a brighter future, paving the way for innovative flood resilience and civil engineering in a nature- and people-positive way,” she added.

The evening highlighted the importance of collaborating with partners like the Environment Agency.

Together, we can ensure we build resilient solutions to protect our communities against the threats of tomorrow.