Thames Barrier Test Day

Today was the annual closure of the Thames Barrier. One of the largest flood barriers in the world, it has protected London from Storm surges and unusually high tides since 1984. It is raised once a month for testing, but a scheduled full closure only happens once a year and is a rather special occasion.

We arrived on the South Bank near Greenwich around 9 in the morning when it was quiet, save for lots of Environment Agency staff bustling about and setting up. We set up a picnic on the grass and waited. By the time things got started an hour later the road was lined with people who had come out to watch.

There are ten gates, four of which lower down and six which lie in the river bed and rise up. They moved one at a time, each one taking about ten minutes to raise or lower. By 11:30 the whole thing was in place. It would stay there until after high tide, and then raise a few meters to allow underspill and level out the water before opening the gates again (we didn't end up staying until the end, so will have to catch the underspill another time. It's apparently a great time to see lots of birds who come to feast on the fish it churns up.)

The barriers have closed 176 times for flood defense (an average of about 5 or 6 times a year) in addition to their routine closures. But it is not intended to last forever... eventually due to climate change and sea level rise the gates will no longer offer complete protection.

The Thames Estuary 2100 Plan developed by the Environment Agency sets out a plan the next 100 years, which of course is largely guess work beyond the short term. As they put it:

"The plan is based on contemporary understanding of predicted climate change, but is designed to be adaptable to changes in predictions (including for sea level rise) throughout the century."

It was interesting to reflect that I have never lived in a place where I was very aware of environmental threats or imagined the Thames as anything other than a beautiful river (with an interesting history of sewage). Until today, as far as I knew Thames Barrier was "that thing that looks a bit like the Sydney Opera House, that you can take a boat to." It's amazing to think about the infrastructure that is in place, and the careful research, thought and engineering that goes into it, without the average person being aware... and that one day changes, no matter how prepared and planned for, will probably take us by surprise anyway. I'm grateful there are people who devote their careers to the subject in so many ways from protecting the environment from harmful chemicals and plastics to tackling the engineering challenges to ensure that when changes do come we are prepared. There were loads of great organizations out recruiting today, and I now have a whole stack of bedtime reading for tonight!

More information on TE2100 is here: https://www.gov.uk/government/publications/thames-estuary-2100-te2100/thames-estuary-2100-te2100
More information and reports on the Barrier are here: https://www.gov.uk/guidance/the-thames-barrier