London flooding: what is a ‘sponge city’ and is the capital going to become one?

There are all sorts of perils in London. On a daily basis Londoners have to avoid being hit by rogue e-bike users and bankrupted by £8 pints. But now there’s an even bigger, potentially ‘lethal’ danger heading for the city. Experts have said flash flooding is the biggest environmental risk facing people living in the capital at the moment, and something needs to be done about it. 

One of the solutions put forward to curb flash flooding in London is to turn it into a ‘sponge city’, which essentially means an urban area designed to absorb rain water. 

After flash floods in 2021, City Hall created the Surface Water Strategic Group to prepare a London-wide flooding strategy. The strategy will be announced later this year. The strategy follows a report released in January by the London Climate Resilience Review, which found the capital was ‘underprepared’ for climate change and called flash floods a ‘lethal’ risk to the capital’s inhabitants. Gulp. 

Thanks to all the concrete and impermeable surfaces in London, the city is not good at absorbing vast amounts of rainwater, leading to surface flooding. But if it was turned into a ‘sponge city’ – following the example of cities like Chongqing in China – more absorbent spaces such as parks, wetlands and ponds would be added to the capital. However, there are concerns that London doesn’t have the space for all this extra sponginess.  

It’s still to soon to say whether this will actually happen in the capital. Discussions about what to do for London as it faces the perils of climate change are still ongoing, and the efficacy of sponge cities is still being tested worldwide. In some cases, sponge cities have been criticised for being designed to deal with the present, when flooding strategies should be looking at the long-term causes of climate change. 

Climate change in London

Why exactly is London flooding so much? Read more here to find out. As well as increased sponginess, glass barriers on the Thames are going to shield London from future floods. But if the Thames bursts, these areas of London might be underwater.

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