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Flood Risk to Urban Basements: A Growing Threat

As storms grow more intense amid climate change, cities around the world face a rising threat - flooding of basement properties. This issue is especially acute in London, which has seen a boom of basement developments even as its antiquated sewage system struggles to cope. With heavier rainfall in the forecast, property owners must take steps to mitigate flood risks.


London is particularly vulnerable due to its aging drainage infrastructure dating back to 1865. This system was built to handle the needs of 4.5 million people, yet today’s population is double that. It already overflows 60 times per year. Moreover, an increasing number of basement developments - over 7,000 added in the past decade alone - reduce natural drainage channels.


The implications of flooding in high-end, fully furnished London basements are significant. Beyond physical damage, electrical systems can be compromised, displacing residents to costly hotels for repairs. This makes insurance difficult to secure.


Property owners do have options to reduce flood risk. One building installed pumps and pressursed pipework to remove water until flooding recedes. Other safeguards include assessing risk, elevating valuables, creating emergency plans and conducting climate risk reviews.


While coverage is shrinking, some products help mitigate insurer excesses in high-risk areas. Technical advice can also optimise prevention strategies. With advanced preparation, London’s basements can weather coming storms.


The key is acknowledging the growing threat posed by climate change, even as the city expands underground. Forward-thinking property owners will take proper precautions.





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