Surface Water Flooding in London - adapting for a changing climate

London was hit by two extreme storms on 12 and 25 July 2021. Parts of London received close to 100mm of rainfall, the equivalent of more than twice the average July rainfall, in just two hours. The rain caused damage and disruption to homes and infrastructure across the city, and many Londoners required rehousing as their homes were flooded with stormwater and sewage. It rendered critical infrastructure unusable with the closure or partial closure of 30 London Underground stations and the evacuation of hospital wards and schools.

Climate change is increasing the intensity of severe rainfall events as a warmer atmosphere can hold more moisture. Although climate projections suggest that London’s summers will become drier, heavy downpours are still expected to become more intense. Without an increase in resilience, London could suffer more and more severe surface water flooding, with greater risks to lives and livelihoods.

While there has been understandable focus on learning the lessons from last summer’s flood events to try to avoid a repeat this year, work has also now begun on a much needed long-term surface water flooding strategy for London that takes account of how climate change is affecting the probability of heavy rainfall.

This London Flood Awareness Week event is jointly organised by the London Climate Change Partnership (LCCP) and the Greater London Authority (GLA) and will bring together experts and stakeholders to share good practice and discuss how to make London more resilient to surface water flood risk now and in the future, taking account of the impacts of climate change. The speakers and panellists include:

Charlotte Wood - Area Director London - The Environment Agency

Catherine Barber - Assistant Director Environment and Energy - Greater London Authority

Alex Nickson - Water Resources and Growth Lead, Thames Water

Sanjay Johal - Community Engagement Manager, National Flood Forum

Cllr Deirdre Costigan - Deputy Leader, Ealing Council, vice chair Transport and Environment Committee, London Councils

Anusha Shah - Arcadis - Panel Chair

The event will provide an opportunity to discuss and showcase short- and long-term responses to the surface water flood events that occurred in London in summer 2021 and give attendees the opportunity to hear about the work underway to develop a strategic plan to manage surface water flooding. Ultimately the event will contribute to overall efforts to realise the vision of London as the most climate-resilient city in the world.

The event will be followed by networking and a drinks reception.