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Turn the grey to green to stop London flooding

Zack Polanski AM Headshot
Created on
15 December 2022

Turn the grey to green to stop London flooding

At a time when London is flooding regularly the Mayor has only delivered one hundredth of his annual target to improve drainage.

Over 100,000 square metres of London that should have improved drainage using SuDs (Sustainable Urban Drainage Systems) has not been delivered since 2019. The Mayor has also confirmed he is unable to properly track progress under questioning from Zack Polanski AM today.

SuDs are designed to reduce risks around flooding which are increased during winter months and the Mayor is on course to miss this target for the third year in a row.[1]

When Zack has asked for more data on SuDs, he has been told the GLA does not hold detailed data on installation by year. Figures given often say more is happening but are unspecific on how much or where this is taking place.[1]

Green London Assembly member Zack Polanski says:

“You can’t track progress if you don’t know what’s being done. The climate is getting more volatile than ever, and London risks another season of flooding.

“I would urge the Mayor to not only meet his target but also make up the shortfall. The grey concrete that covers too much of London can gather rainfall into devastating floods which particularly threatens those living in basements.

“We must break up that concrete and replace it with green spaces that absorb water, letting it drain away over time instead of flooding our homes. The Mayor has missed this target for too long – he must commit to taking SuDs seriously, prioritising tracking and encouraging boroughs, businesses and landowners to do more.”

The Mayor has a target for TfL to drain 50,000 square metres a year of highway catchment into SuDs. In 2021/22 TfL only installed SuDs that drained 500 square metres.[1]


Notes to editors

Zack is available for interview.

The Deputy Mayor has acknowledged that climate risks affect those Londoners with the least economic resilience: https://www.london.gov.uk/press-releases/assembly/zack-polanski/extreme-climate-incidents-an-annual-event

[1] Data from two MQs by Zack Polanski AM on London’s Sustainable Drainage System progress MQ 2022/0016 https://www.london.gov.uk/who-we-are/what-london-assembly-does/questions-mayor/find-an-answer/londons-sustainable-drainage-system-progress and MQ 2022/3603 https://www.london.gov.uk/who-we-are/what-london-assembly-does/questions-mayor/find-an-answer/londons-sustainable-drainage-system-progress-2

Year

TfL

(sq m)

Boroughs (sq m)

Boroughs (number)

Total

Shortfall

2019-20

80

‘at least’ 22,437

13

22,517

27,483

2020-21

1,750

9,715

12

11,465

38,535

2021-22

500

6,785

No figure given

7,285

42,715

In total this is a shortfall of 107,733 square metres of land that could have been given drainage using SuDs.

Note that the answer to MQ 2022/3603 says that the GLA does not hold fully detailed data on SuDs.

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