As the risk of flash flooding due to climate change in the capital increases, the Mayor of London, Sadiq Khan, is writing to Londoners in 45,000 basement properties to urgently raise awareness and help them prepare in the event of a flood.
The Mayor is warning Londoners that the effects of climate change are now on our doorstep, with an increase in devastating flooding in the capital in recent years and predictions of more frequent and serious floods in future.
In July last year, severe flooding damaged thousands of homes and businesses in London, rendering many Londoners temporarily homeless as their properties were filled with stormwater and sewage. Parts of London received over a month’s rainfall in just two hours, the equivalent of more than twice the average July rainfall.
In recent years, London has seen the impact of the climate emergency first-hand with soaring temperatures and flash floods in the capital. City Hall analysis has shown that if the necessary action is not taken and extreme temperatures and flooding continue to get worse, a quarter of London’s rail stations, one in five schools, nearly half of London’s hospitals and hundreds of thousands of homes and workplaces will be at risk of flooding in the future.
Flash flooding can happen when very heavy rain falls on hard surfaces overwhelming drainage and sewers. This sort of flooding is difficult to predict, it often happens quickly with fast flowing water that could pose a risk to life. It is also more likely to happen during intense summer storms. The likelihood of flooding remains low for most basement properties, but where it does occur, damage and risk to life can be serious.
A new leaflet will be distributed to these properties across London offering practical advice and guidance to residents about how to prepare for and deal with a flood and Sadiq Khan has made reducing emissions to tackle climate change a key priority of his mayoralty – including setting a target of 2030 for London to reach net-zero emissions.
Londoners will be advised to sign up to receive weather warnings through the Met Office alert email, check drains in and around the home are clear and ensure they are aware how to turn off water, gas and electricity supplies. In addition, they are advised to prepare a ‘flood kit’ of important items in case they have to evacuate their homes, containing warm clothing, a phone charger, any vital medication and important documents such as proof of insurance. The leaflet also shares the steps to follow if a flood occurs.
In addition to the devastating effects on homes, last summer’s flash flooding led to issues with critical infrastructure including the closure or partial closure of 30 Underground stations, as well as the evacuation of schools and hospitals. In some of the worst cases, students have still not been able to return to classrooms damaged by the floodwater.
Immediately following the floods, the Mayor brought together those responsible for flood prevention and response in the capital to address the longer-term risk of surface water flooding due to climate change. The group, which includes the London Fire Brigade, boroughs, TfL, water companies and the Environment Agency has also looked at the response to and reducing the impacts of extreme events in London. The risk to those living in basements has repeatedly been raised as a key concern.
The Mayor of London, Sadiq Khan, said:
“The climate emergency is the biggest global threat we face today. The serious flooding in London last year shows that the climate crisis is no longer a distant problem, but one that is increasingly reaching our doorsteps. As Mayor, I’m determined to build a better London for everyone - ensuring we are taking action now to make our city more resilient to the impacts of climate change and making London a global leader in reducing carbon emissions.
“While the likelihood of flooding remains low for most basement properties, I’m doing all I can to ensure that the people most at risk know what to do in the event of a flash flood. This leaflet is designed to help people prepare for flash floods, which we expect to happen more frequently in our city. Be prepared – it could help to save lives
Charlotte Wood, Environment Agency Deputy Director for London, said:
“The flooding in July 2021 led to significant surface water impacts in parts of London. Due to the impacts of climate change these short duration intense rainfall events are likely to occur more frequently in the future. Local authorities are responsible for managing the risk of, and response to, surface water flooding, but all sources of flooding require us, local authorities, emergency responder, water companies and other partners to work together.
“We will continue to actively support our London partners to help London to adapt and become more resilient to such localised extreme rainfall events, and to identify opportunities to streamline access to funding for surface water schemes.”
London Fire Brigade Assistant Commissioner Patrick Goulbourne, said:
“We are seeing an increase in the number of weather related flooding incidents in London and that is likely to continue.
“It is really important that Londoners, particularly those living in basement properties, are prepared and know what to do should a flood occur. Pay attention to weather alerts and prepare a flood kit or grab bag. People can use sandbags to limit the water flow and move belongings to a higher level where possible. If you have neighbours that are vulnerable, please make sure you check on them.”
Notes to editors
Flash flooding (also known as surface water flooding) can happen when very heavy rain falls on hard surfaces overwhelming drainage and sewers. This sort of flooding is difficult to predict, it often happens quickly with fast flowing water that could pose a risk to life. It is also more likely to happen during intense summer storms. The likelihood of flooding remains low for most basement properties, but where it does occur, damage and risk to life can be serious.
Statistics of flood risk from London Flood awareness Week 2021 https://www.london.gov.uk/city-hall-blog/london-flood-awareness-week-2021
The flash flooding roundtable first met on 27 July 2021. The roundtable includes senior leaders from London Councils, TfL, the London Fire Brigade, Thames Water, Affinity Water, SES Water, the Environment Agency and other organisations with responsibilities for responding to or managing surface water flood risk in London.
The roundtable identified the need for more investment in surface water flood management, a more strategic approach to delivery, redoubled efforts in incident preparedness and response, improved communications and coordination, and improved community resilience. While the incident response has been led by London’s existing emergency management/resilience apparatus, the roundtable established a task and finish group to examine the challenges of longer-term management of surface water flood risk in the context of climate change.
The task and finish group reported its findings in February 2022 and are due to meet again later in the year.
Actions already delivered include improvements in multi-agency incident planning and response, data sharing and communications; both between partners and also improved public communications both in advance of and during a flood incident. The report also sets out the task and finish group recommendations, which include the need for a more strategic approach to managing surface water across the capital; clearer and stronger governance arrangements for managing flooding, more funding and the need to urgently identify and reduce the most acute risks, such as risk of flooding to basement properties.
The full report can be found here: https://www.london.gov.uk/WHAT-WE-DO/environment/environment-publications/surface-water-flooding-london
Through the Greener City and Grow Back Greener Funds the GLA is providing funding for projects with adaptation (including flood risk) benefits. These projects include Sustainable Urban Drainage Scheme (SuDS) features.
The Green New Deal Fund is providing in excess of £10m of funding to address a range of environmental priorities, including projects that deliver nature-based climate adaptation measures for flooding and water management. Programmes include the Future Neighbourhoods 2030, Green and Resilient Spaces, and Climate Resilient Schools, which are funding projects with local adaptation benefits, including SuDS features
The Climate Resilient Schools programme is a partnership between the Mayor of London, Thames Water and the Department for Education, working with up to 100 of the most a risk schools to flooding. This is being done by installing SuDS, providing education resources and climate adaptation plans. This programme is due to be complete by March 2023.
The Climate Risk Map for London - published last year, identifies areas of London that are most exposed to climate impacts with high concentrations of vulnerable populations - https://data.london.gov.uk/dataset/climate-risk-mapping
The London Sustainable Drainage Action Plan has been helping reduce the risk of surface water flooding across London. Actions include working with boroughs and other risk management authorities to install sustainable drainage systems (SuDS) across London.
The GLA have been working with partners on a new approach to quantify the benefits of small SuDS schemes across London in managing surface water flooding. This approach has helped bring in £1 million of new flood funding for small sustainable drainage schemes across London.
At the local scale, paving over gardens and driveways remains a problem. The Mayor’s London Plan discourages development proposals that include impermeable surfaces but much of this paving is done without planning consent. Guidance has been published which sets out how to go about and the benefits of doing this, including more green infrastructure.