Investigation into 2021 flooding published

Published: Thursday 30 June 2022

An investigation into flooding in Kensington and Chelsea last year has found the scale of rainfall was a one in 185-year event in parts of the borough.

Kensington and Chelsea experienced extreme flooding on 12 July 2021, affecting at least 340 properties in the borough. Properties also flooded in Hammersmith, Westminster and Camden. 

The Met Office had issued a broad-reaching yellow warning for thunderstorms spanning South East England, from 10am to midnight on the day. In the south of the borough the event was a one in two year event, compared to 1 in 185 years further north in Notting Hill. 

In Kensington and Chelsea, the council set up rest centres at The Curve and Henry Dickens Court Community Centre and supported 120 into temporary accommodation. So far the council has spent around £900,000 on costs associated with flooding of its properties, including repairs and temporary accommodation.

The Council’s report has recommended actions to protect residents in the future. 

Cllr Cem Kemahli, lead member for planning, place and environment, said:

“Flooding is devastating. It destroys homes and businesses and takes a huge toll on people affected. 

“Whilst last year’s flooding event was rare, we need to act now to protect people and property in the future as our climate changes. Our investigation has found areas where the Council, our partners and our communities can prepare to minimise the impacts.

“We have already developed more detailed local forecasting, so we can make warnings clear and specific for our residents.”

The source of flooding was heavy rainfall which flowed overland and drained into gullies and sewers. Many sewers surcharged, with drains overflowing and flooding properties inside, by backing up through domestic wastewater pipes and coming up through toilets and shower drains. Basement properties were particularly affected. 

Sewers are the responsibility of Thames Water and immediately after last year’s flooding Council Leader Elizabeth Campbell wrote to Thames Water asking them to investigate the incident and their own response. Their investigation is happening in four parts. The Council’s environmental scrutiny committee has added this to their workplan this year and will be calling Thames Water back to committee to present their findings.

The Council is also consulting residents on a new sustainable drainage system in Portobello. Sustainable drainage systems provide ways to manage rainwater through nature, such as rain gardens and raised planters.

If you live in a basement property, here are some simple tips you can take to prepare for a flash flooding event:

  • Sign up to weather alerts
  • Sing up to weather alerts at
  • Put your valuables on a high shelf to protect them from water damage.
  • Make sure you know how to turn off your water, gas and electricity supply.
  • Check your household building or contents insurance covers flooding.
  • If you don’t have any, FloodRe is a re-insurance scheme which may be able to help. 
  • Save phone numbers such as your insurance company, landlord, housing association and local council in your phone.
  • Check drains outside your home and on your street are clear.
  • You can report any street drainage issues at [email protected]
  • Prepare a flood kit including warm clothes, medicines, torch, phone charger and important documents such as a passport or insurance documents. 

The investigation will be published in full this week. Read it, along with more information about July 2021 flooding.

Report previous sewer flooding to Thames Water.