The Mayor should use his leadership to press forward action to address the serious risk of flood damage and potential loss of life London faces if there is severe rainfall, a new report from the London Assembly says today.
For a Rainy Day by the Assembly’s Environment Committee warns that, if London gets rainfall similar to that which caused flooding elsewhere in the UK in 2007, some streets could flood within minutes and rivers soon after. Lives could be lost and damage to property could amount to tens of billions of pounds.The capital is particularly susceptible to flooding because it is so built up and water quickly gets into drains and rivers. Once these are full, water floods across the land’s surface putting up to 680,000 properties in the capital at risk from surface water flooding.
The report says it is just chance that London has so far escaped rainfall severe enough to cause widespread flooding, and warns that climate change increases the annual likelihood of severe rainstorms. Yet there is little information currently about the risks of surface water flooding, and awareness of flooding among Londoners is patchy.
The Committee’s report calls on the Mayor to help assess and communicate the risk of surface water flooding and support practical measures to reduce flood risk. It also urges him to help identify and secure funding from a wider range of sources to cut London’s flood risk and remove obstacles to river restoration projects.
Darren Johnson, deputy chair of the Environment Committee, said: “It is pure luck that London has so far escaped the kind of flooding that devastated other parts of the country in 2007, and we know that climate change makes severe rainstorms more likely in the future.
“To protect lives and help prevent extensive property damage, Londoners need to be better informed about flood risk and the Mayor must lead on ensuring everything possible is done to protect people’s homes and businesses.“
In London, local boroughs and the City of London are responsible for surface water and small watercourses. Main rivers and tidal water are within the remit of the Environment Agency.
However the report says the Mayor has an important role in ensuring these bodies are effective and is well placed to increase action in key areas through his direct powers, leadership and influence.
The report specifically calls on him to:
- Ensure surface water flood risk information is publicly available, alongside information for householders of what they can do if they are in a flood risk area.
- Extend a funding scheme for green roofs to include other forms of sustainable drainage and use sustainable drainage, if possible, in GLA group property.
- Retain and show a plan to achieve his target to restore 15km of rivers in his Climate Change Adaptation Strategy.
- Support a call for water companies to be able to work directly with householders to correct misconnected drains.
- Take steps to identify and secure funding for work to reduce flood risk in London.
In addition the Committee wants the GLA to help facilitate partnerships between public and third sectors to fund flood risk mitigation schemes.
Notes for Editors:
- See the report For a Rainy Day
- During 2007 55,000 homes in the UK suffered flooding. See the Environment Agency’s report on the 2007 floods
- See P14 of the report
- Detailed maps do not yet exist to calculate surface water flooding risk in detail but it is thought there are up to 680,000 properties in London at risk with a likelihood of at least 0.5 percent in a year. See P42 of the Mayor's draft Climate Change Adaptation Strategy, which is based on Environment Agency data.
- See P15 of the report
- The Drain London Forum, established by the Mayor, is shortly expected to produce maps on expected surface water depth and flow speed across the capital for various rainfall scenarios.
- London is at risk of flooding from five sources: tidal, river, surface water, sewer and groundwater. The Committee’s report focuses on surface water and river flooding.
- The report will be formally agreed at the next Environment Committee meeting.
- The Deputy Chair of the Environment Committee, Darren Johnson AM, is available for interview. See contact details below.
- As well as investigating issues that matter to Londoners, the London Assembly acts as a check and a balance on the Mayor.
For media enquiries, please contact Julie Wheldon/Lisa Moore on 020 7983 4228/4283. For out of hours media enquiries, call 020 7983 4000 and ask for the London Assembly duty press officer. Non-media enquiries should be directed to the Public Liaison Unit on 020 7983 4100.