IPCC Report & flash flooding in London

 

Flooding of the basement at the family house along Warwick Avenue

Flood warnings have been issued in London previously but the flash floods in West London and South West London in recent weeks still hit home hard. As forecasters warn of water spray, sudden flooding and lightning strikes, which could lead to power cuts, damage to buildings and delays to public transport. It came as the UK and London recorded its hottest day of the year so far, after the temperature reached 32.2C (89.96F) at Heathrow Airport in west London on 20th July. Public Health England has also extended its heat-health warning, which warns people to take measures to stay cool and look out for vulnerable people in recent days.
 
So Londoners increasingly recognise the impact of climate change on London not just in terms of increased temperature, but also more rare and unpredictable weather events, which may mean people, who never thought they would be affected, have their homes severely impacted by flash floods. 
At the London Assembly as Chair of the Environment and as Chair of the London Waterways Commission under both Ken & Boris mayoralty, we tackled the issue in 2014 when we were told by the Environment Agency that some 24,000 were under flood risk and current plans will protect 10,000 of them, the high risk ones identified in their boroughs as the table shows below. 
We recommended that sustainable drainage and river restoration could help to protect to protect the 24,000 London properties at risk. 
Further back then that, the Environment Committee Report on Crazy Paving in 2005 suggested clearly that losing London’s front gardens won’t help as we adapt to increasing flash floods as a result of climate change. It was suggested that 2/3rds of Londoners front gardens are already covered by surfacing other than vegetation, that is paving, bricks, concrete or gravel of a total surface area of 12 sq miles equivalent to 5,200 football pitches. Their loss is placing an increasing burden on London’s underground drainage system, as the increase in run-off from impermeable surfaces such as concrete can be three times greater than run-off from porous surfaces. 

The IPCC Report releases this week confirms that heavy rainfall will be more frequent and intense. So London’s flooding is sure to worsen, as further development means flood plains being covered by concrete. One way of responding is saving our front gardens at least from the work of the Environment Committee at the London Assembly.