London's Fleet sewer or in the footsteps of Sir Joseph Bazalgette

Written by Nika Garrett on .

London’s Fleet sewer or in the footsteps of Sir Joseph Bazalgette

Among the bags left in the middle of the pavement I find one that bears my name. There are quite a few things inside that I need to wear; white overalls, a helmet with a torch, thick gloves, harness and impressive long boots. I also get thin rubber gloves to wear under my thick gloves so that I can take photos with my little camera. 5 minutes later we take a few group shots and we are ready to go down London’s Fleet sewer. The whole thing feels very much surreal.

As I walk some 3 meters down the narrow metal ladder and then stand in what feels and smells like a very small and damp cellar, it becomes perfectly clear why it is not an adventure that can be offered to the public. I can only imagine what it would feel like to someone who suffers from claustrophobia for instance… In fact, there is quite a long list of medical conditions I’m happy I don’t have. Otherwise, I wouldn’t be here.

There is barely enough space for 5 or 6 of us standing here around a fascinating looking machinery. This machinery turns out to be penstock winding mechanism that is used to open and close a gate in order to control the flow of sewage. It is Victorian and there are only about dozen of them in the whole sewage system in London.

We are now off and into a narrow tunnel and I soon realise what a complex system it is. At one point we are looking at sewage carried down the river Fleet and later we stop to see where sewage is carried out of the river Fleet. It goes down the pipe and off to East London to Beckton Sewage Works. There is also a fascinating moment later during our tour when we can see just above our heads metal plates with a notice: “This is London Underground property”. We are under the tube tunnel!

What an amazing engineering!  I’m walking in the footsteps of Sir Joseph Bazalgette who designed the sewage system over 150 years ago. Here under a thin layer of sewage there is most wonderful looking brickwork and massive metal gates and the system that we Londoners still depend on.

The torches on our helmets are most useful as we can point towards certain things our guide is telling us about. I also use it as additional light as I take photos. Needless to say, if it wasn’t for our torches, we would be making our way here in complete darkness like sewer rats. The thought of getting lost here is as alarming as the thought of a close encounter with a sewer rat.

As we are making our way through narrow and low tunnels I’m a bit afraid to look up or touch things.  At some point we notice something that looks like a bundle of grey hair and yet when someone (not me!) touches it, the whole thing starts melting… Later on one of us spots a cotton bud stuck to a wall… I’m grateful it is just a cotton bud.  It is indeed a life changing experience.

So far the smell has been bearable and as the tide is low we haven’t walked deep in anything yet. There is another ladder to climb down and we must be now some 10 meters below the ground. We have had some dry period recently but when it rains and the sewage overflows it is carried through an outfall sewer. Then the sewage is pushed through two sets of gates. Those gates act like valves and they let sewage out into the Thames but don’t let the river back in.

 It is in this outfall sewer that we happen to be now and the atmosphere starts changing… Soon I end up walking up to my knees in sewage, black and thick and the smell is getting worse. I still find it bearable but I don’t know how much longer… It makes me think how bad the stench of the Fleet river must have been when it turned into an open sewer flowing into the Thames and how unbearable 1858 Great Stink was.   "To where Fleet-ditch with disemboguing streams / Rolls the large tribute of dead dogs to Thames/The king of dykes! than whom no sluice of mud/with deeper sable blots the silver flood" wrote Alexander Pope already in 18th century.

Meantime here in the outfall sewer we take a couple of group photos while up to our knees in sewage before we had back and can get some fresh air… Our tour happens however on the day when the air pollution in London is at its worst so the air doesn’t smell that fresh at all. That evening I upload about 90 photos. I am about to delete some including one that is blurred but then it strikes me that it looks like a face… I can’t help but think that a place like that must have some ghosts wandering those tunnels as well down the lost Fleet River and in the footsteps of Sir Bazalgette…


When Sir Bazalgette designed his sewage system over 150 years ago the population of London was about 4 million, today it is about 8 million. While it is in a perfect working condition, it can’t cope with the amount of sewage. Even 2 mm of rainfall can trigger a discharge of untreated sewage into tidal Thames. Learn how the proposed Thames Tideway Tunnel would help solve this problem.

I’m most grateful to Thames Tideway Tunnel for the invitation to join this fascinating tour and for providing additional information and assistance regarding this blog post.

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