University of Southampton: Thames Estuary report highlights changes over decade

Sea levels in the Thames Estuary are rising faster now than ever before, according to a report released today by the Environment Agency, supported by the University of Southampton.

The report, which looks at how the Thames Estuary has changed over the past 10 years, marks the first key milestone in the 10-Year Review of the Thames Estuary 2100 Plan.

The Thames Estuary 2100 Plan was the first UK flood risk management strategy to put climate adaptation at its core. It is a trailblazer of the adaptive approach set out in the Environment Agency’s National Flood and Coastal Erosion Risk Management (FCERM) Strategy published last year.

The report looks at 10 indicators of change, ranging from sea level rise and river flows, to people and property in the floodplain, which are then assessed against future flood risk.

The key findings of the review include:

sea levels are increasing in the Thames Estuary and could rise by as much as 1.15 metres by 2100 under the higher climate change scenario from UKCP18
the Thames Barrier and its associated defences play a vital role in protecting London from tidal flood risk – protecting over 1.4 million people, and half a million properties worth over £321 billion, from flooding
since it officially opened in 1984, the Thames Barrier is nearing its 200th closure
the Thames Estuary’s flood defence system also protects 55,640 businesses, 4 World Heritage Sites, over 4,000 listed buildings and 27 km2 of open green space
working with partners, we have created 58 hectares of new compensatory habitat at Salt Fleet Flats in Kent and Wallasea in Essex.
The report, which summarises the key findings of a much larger study, has been supported by the Met Office and the University of Southampton. It found that since the Thames Estuary 2100 Plan was developed in 2010, sea levels have continued to rise as a result of climate change. Between 1990 and 2018, it rose by 3.6mm per year on average, compared to 1.43mm per year between 1911 and 2018.

The findings will be used to review and update the recommendations for managing tidal flood risk and planning for our future riversides in the Thames Estuary. This will form the basis of the updated Thames Estuary 2100 Plan, which will be regularly monitored and evaluated as our climate changes. By taking an adaptive approach, we can better anticipate and respond to a range of future climate scenarios, ensuring we are investing in the right flood risk management actions at the right time, to ensure the resilience of the estuary and its communities.

A team from the University of Southampton played a key role in supporting this important study, digitising and analysing over 100 years of historic sea level records from fifteen tide gauge sites along the length of the estuary.

Dr Ivan Haigh, Associate Professor in Coastal Oceanography at the University, says:

“I am thrilled to have led the sea level data analysis which supporting this vital review.

“These new sea level records we captured and analysed are now amongst the longest in the UK, and were foundational for significantly enhancing our understanding of changes in both mean sea level and extreme water levels across the Thames Estuary.

“Our novel analysis showed that the rate of sea-level rise is rapidly accelerating driving an increase in the number of extreme water levels. Continuous monitoring of this change is vital to ensure that the right flood risk management actions are taken at the right time, to safeguard London and the Thames Estuary’s continued existence as one of the world’s most important coastal regions.”

Baroness Brown, Chair of the Government’s Climate Change Committee and Chair of the Thames Estuary 2100: 10-Year Review Advisory Group said:

“Keeping London and the Thames Estuary protected from flooding as our climate changes is critical. Only 12% of over 3,000 flood defences that provide this protection are the responsibility of the Environment Agency, so it is essential that the Thames Estuary 2100 Plan is a team effort, owned by everyone with an interest in our river.

By working together we can ensure that people and the economy are safe, and that this is done in a way that combines nature-based solutions with the latest innovations in flood risk management, to enhance nature and increase the amenity of the river.”

Julie Foley, Director for Flood Strategy and National Adaptation at the Environment Agency, said:

“This report is a significant first step in updating our world leading approach to the 2100 Plan for the Thames Estuary, home to some of the country’s most valuable assets, critical infrastructure and internationally-protected habitats.

The Environment Agency is committed to reaching net zero by 2030. But with sea level rises, it is equally important that we plan to adapt to the unavoidable impacts of climate change. Through the Thames Estuary 2100 Plan we are taking an adaptive approach so we are agile to the latest climate science, growth projections, investment opportunities and changes to the local environment.

In the year of the United Nations Climate Change Conference, it is more important than ever that we show leadership in tacking the climate emergency in the Thames Estuary.”

Samantha Kennedy, Director for the Environment and Climate Action at Essex County Council and a member of the 10-Year Review Advisory Group, said:

“There are significant social, environmental and economic benefits that could be delivered through reshaping our riversides, including reaching net zero and tackling climate change.

“I’m really pleased to support this important piece of work, which is so vital for keeping communities, businesses, and infrastructure in the estuary protected from rising sea levels, and enabling truly sustainable growth.”

The Environment Agency will be working with partners to review the findings from the report and to review the recommendations for managing tidal flood risk in the Thames Estuary. This work is due to begin in the Autumn and the updated Plan will be published in 2022.