London must organise and act to cope with climate change flooding, Assembly hears

Londoners can expect more flash flooding such as occurred in the capital in July and August, with climate change bringing more extreme weather in the coming years, London Assembly members heard yesterday.

The city must learn to manage the consequences, the Assembly’s Environment Committee was told. “We can’t halt climate change. We will see more flooding. We need to work to adapt and create a resilient city,” said Environment Agency London director Charlotte Wood.

The challenge is significant, AMs heard. The Thames Barrier, preventing high tides and storm surges flooding the city, had been closed 24 times in its first 17 years of operation but 71 times in the next two years, said Wood, while Met Office expert professor Jason Lowe warned that London temperatures could rise by up to 4.1 degrees by the 2050s, heralding more floods.

While the transport network had coped relatively well – “Back up-and-running the next day”, after the dramatic summer scenes of water surging through stations, Transport for London chief safety officer Lilli Matson said, she “could not guarantee” there would not be further flooding.

The Thames Water drainage system had not failed during the summer, but was “overwhelmed by events beyond its capacity to manage,” said the company’s wastewater systems strategy manager Alex Nickson.

Adaptation rather than prevention was the message, along with better advance warning and closer working between the various agencies involved. “Getting all that water underground is not the solution for the future,” said Nickson. “We need to manage that water on the surface. And we are way off from getting greater accuracy in forecasting.”

An independent review commissioned by Thames Water will be considering longer-term solutions, as will a new London-based grouping, jointly chaired by the Environment Agency and London Councils, set up after Sadiq Khan hosted a high-level roundtable in July to look at “what more can be done”.

The two probes will have a hefty agenda, summed up at the meeting by Patricia Cuervo, senior flood and water management officer at Kensington & Chelsea council: “We need to improve working together, understand roles and responsibilities and understand our assets, with better forecasting and more resources.”

Who’s in charge? Not straightforward, said City Hall head of climate change Peter Daw. He explained that the Mayor has no direct responsibility for managing flood risk, and while the Environment Agency has a “strategic oversight” role, individual boroughs are designated as local flood management authorities.

There has been no shortage of thinking about the issue, said Wood, including a high-level extreme rainfall summit in 2016 and a further review last year, which concluded that “clarity as to who is responsible…is often lacking”, to which the government responded in July. Green AM Caroline Russell also warned about the extent of flood risk to the Underground in a 2019 report.

There is a need for “more effective coordination across all of the authorities involved,” said Daw. “We need better data and some urgency on better collaboration,” said Matson. “It’s now about how we can work better together,” added Wood. The meeting heard that it is still sometimes not clear who owns what asset.

Thames Water faces the challenge of maintaining 110,000 kilometres of sewers, and there is a need for higher flood walls along the Thames – the City of London Corporation is the first authority to begin that process.

A shift towards individual property defences as well as more “green” infrastructure to help the capital cope with surface water was was mentioned as important, with Matson saying London should become more of a “sponge city”.

And there was agreement that money is short, with Nickson conceding that Thames Water’s drainage system “would be in a museum if it was in America”.

“Future funding is a really big thing,” said Wood, while TfL’s Matson urged that, with negotiations over further financial support for TfL now getting underway, the government needs to “make adaptation a real priority”.

On London is a small but influential website which strives to provide more of the kind of  journalism the capital city needs. Become a supporter for £5 a month or £50 a year and receive an action-packed weekly newsletter and free entry to online events. Details here.