Future of Thames River flood defences is focus of London presidential visit

During the last week of June, accompanied by Future Leaders Rohini Pattani and Svetlana Joao, I met with the ICE’s London regional committee in City Hall to hear about their activities.

There were presentations by Frederick Levy (secretary), Phebe Mann (chair) and Oana Sala (ECNet chair).

This was followed by a presentation from the Environment Agency (EA) on the development of a long-term strategy for managing the flood defence assets on the Thames estuary, in the face of rising sea levels and more intense storms due to climate change.

We also heard from some of the senior operating staff at the Thames Barrier on the challenges of maintaining a 45+ year old critical asset, and on potential options for a replacement, which will be needed before 2070.

Already, the barrier is being used far more often than originally planned for.

The Thames’ flood defences: what’s next?

We followed the presentations with a roundtable, where we discussed how the work which is going to be required to update the Thames’ flood defences can best be procured and managed.

There are over 3,000 riparian (riverbank) owners of flood defence assets along the length of the Thames, many of which will need to be raised substantially or replaced.

Matters discussed included:

• whether we would need new legislation to facilitate delivery and deal with the multiple ownerships;
• whether we needed a Special Project Vehicle (as with other major projects such as HS2) to deliver an undertaking of this scale, which may be outside the EA’s capacity;
• whether we should use a hybrid bill rather than the usual planning approach; and
• options for replacing or modifying the barrier.

The EA staff felt that there was considerable merit in continuing these discussions and the London region agreed to follow this up.

Seeing the Thames Barrier up close

A few of us then had the opportunity to visit the Thames Barrier and see some of the ongoing maintenance and improvement works.

We also visited the control centre which monitors weather and water levels from numerous gauging stations, as well as the operating status of the plant and equipment.

We were fortunate to see one of the rising sector gates and one of the radial gates raised out of the water for maintenance.

We learnt that the gates need to be raised every couple of weeks in sequence to make sure they are operating properly.

Thanks to Frederick, Phebe, Oana and Siu Ng of the Environment Agency for arranging the programme.