Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what steps he has taken with relevant authorities to ensure that the Thames barrier will be able to cope with fast and heavy rainfall.

London is at risk from many and varied sources of flooding – including tidal, surface water, and groundwater flooding.

Surface water flooding is localised and complex. It can happen very quickly, be difficult to predict and can be exacerbated by the impermeable built environment and an overwhelmed drainage system.

HM Government is committed to tackling this risk and in April 2020, we made changes to the partnership funding policy to enable more surface water schemes in our new £5.2 billion flood defence programme. Approximately 34% of the 2,000 flood defences planned will be for surface water management.  This includes £29.4 million being spent in London – over three times the amount that was allocated in the previous investment programme. Combined with partnership funding, this investment is forecast to better protect 2,590 properties by 2027.

Since 1982, the Thames Barrier has been protecting London from flooding caused by tidal surges. It works with the complex systems of assets (including flood walls, gates, embankments and smaller assets) along the Thames and its tributaries to prevent flooding to London’s homes, businesses and key infrastructure. This is what it is designed to do. It does not have a role in mitigating other forms of flooding, such as from surface water.

The Environment Agency currently closes the Thames Barrier 5 times a year on average to prevent tidal flooding. We expect the Thames Barrier to continue to protect London from tidal flooding up until 2070. The Thames Estuary 2100 Plan identifies several long-term options for a future Thames Barrier to protect the Thames Estuary and London to the end of the century and beyond.