The Thames Tideway Tunnel: What I learned from The Future of Green Infrastructure – SuDS, Sewage & Tideway.

By April 4, 2018 No Comments
4th April 2018
by Charlotte Hawthorne

When you think of a relaxing cruise down the Thames, the last thing you think about is getting excited about a sewage-outlet guided tour. However, some pretty exciting developments are taking place along the river, changing London’s infrastructure for future generations. If you haven’t heard the news already, there is an undergoing construction of the Thames Tideway Tunnel (a.k.a the “super sewer” – a name not to be used in the presence of an engineer who is likely to tut in disdain and correct you with the term Sustainable Drainage System, SuDS for short, or storage-and-transfer tunnel).

Despite the sewage outlets not being the most aesthetic of views, I highly recommend the SuDS, Sewage & Tideway cruise if you want to see London from a completely different perspective, learn some fun facts on the history of, and our relationship with, the river, and the ins and outs of the Thames Tideway megaproject. This pivotal moment also allows us to imagine a different, healthier, relationship with the Thames and space for ecological restoration and green infrastructure in the city. You may just be wondering: what on earth are the consequences of all these Londoners – over 8 million of us- going to the toilet every day? Also a very interesting question.

Our problematic relationship with the Thames: waste overflow.

The city of London has grown and grown thanks to one of the greatest natural wonders and assets we have: the river Thames. It provided early settlers with the resources necessary to survive and thrive, and the romans with a strategic connection to the rest of Europe. It has undoubtedly been a key ingredient to London’s flourishment. Basically, as Londonders we owe a lot to the river, but sadly the way we interact with it does not do it justice…

London currently carries a densely packed population of over 8 million people. All of us go to the toilet, wash our bodies, clothes and dishes, and in the process collectively use more than 2.6 billion litres of water every day. All this dirty water is funneled into a “combined” system- a rather inefficient system where rainwater runoff, domestic sewage, and industrial wastewater all ends up in the same place, to be treated and let back out into the water body. However, when we have rainy days in London the system tends to overflow and “emergency” discharge points- or combined sewer overflows (CSOs) –  are opened up releasing astounding amounts of untreated sewage into the river, breaching the EU Urban Waste Water Directive and causing ecological disasters. There is a total of 23 discharge sites along the river to be upgraded. Falconbrook Pumping Station alone, situated near Clapham Junction, releases 42 discharges a year which is a total of 700,000 tonnes of untreated wastewater. A rainy day in London is a common experience as we all know, and this “emergency” overflow situation is hardly treated as an emergency as it happens as regularly as 2 to 3 times a month.

A Bit of History

The fact that the current sewage system is so inefficient is because it’s based on Victorian infrastructure built for what was back then a population of two million. Until the mid 19th century, London only had cesspits and sewers which emptied directly into the river, causing cholera outbursts and unbearable smells. At this point in popular culture, the figure of Father Thames was transformed from a mighty river god to a filthy vagrant called “Dirty Father Thames”[1], encapsulating the dire state of the waterway. It got to the point in the summer of 1858 that the smell of untreated human waste and industrial effluent became too much – an event coined The Great Stink. Politicians could no longer sit in the houses of parliament due to the stench, so they designated civil engineer Bazalgette with the task of upgrading the sewage systems.

Developments have taken place since the Bazalgette’s work, but not enough to deal with London in 2018 and it’s current population.

Images source:

Thames Tideway Tunnel: A new relationship with the Thames?

It is obvious that something has to change. We cannot carry on releasing a total of tens of millions of tonnes of untreated sewage into the tidal River Thames every year. Tideway’s solution is to intercept the current CSOs. In short, instead of the overflow going into the river, it will go into the tunnel where the waste will be redirected to Beckton Sewage Treatment plant. The river will no longer be used as a giant “toilet”[2], or “one vast gutter, one tremendous common shore” (from the poem “Dirty Father Thames”, 1848).

[1] Image: “Dirty Father Thames” (1848) Filthy river, filthy river, Foul from London to the Nore, What art thou but one vast gutter, One tremendous common shore? Punch Magazine – Original: Cartoon from Punch Magazine, Volume 15 Page 152; 7 October 1848 This copy: Punch archives.


The Tunnel works started back in 2016 and the megaproject is expected to take up to seven years to complete, costing a approximately £4.2 billion. There are a total of 24 construction sites, 11 located along the river which can be pinpointed using the map below:

What is also interesting about the Thames Tideway Tunnel  is that is will end up creating a total of 3.5 acres of new public foreshore. Many of the constructions along the river will give way to new patches of privately owned, yet publicly accessible, space which could allow for closer interactions with the river and greenery contributing to a “livable streets” culture in London. If designed and managed with green infrastructure in mind and space for people, not vehicles, these patches could make a great lunch-break spot, encourage nature-contact and provide restorative green space amongst the hussle and bussle of the city. For example, the The Blackfriars Bridge Foreshore site and Victoria Embankment Foreshore sites are shown below:

The Tideway Tunnel ties into many sustainability-related themes and topics. SWIG presented several interesting point from which to start a conversation, such as: what is the future of water infrastructure? With floods and droughts becoming more common, we have to think about how green infrastructure, an approach to water management that protects, restores, or mimics the natural water cycle, can aid London into becoming a “sponge city”. As Londoners, we can take this opportunity to think about ways we can shift towards a healthier relationship with the river and the water we use. Here are some water-friendly individual actions we can take:

  • Take short showers- about four minutes long or less would be ideal. Try listening to one song while showering and by the time it’s finished, get out! In the average UK household, taking shorter showers is one of the most impactful actions to save water.
  • Always fill up your washing machine and dishwasher to full load, and run on short, low temperature cycles.
  • Use less – or no- harmful chemicals to clean your house, dishes, and body. The most natural products, or no products at all, the better. Find eco-friendly alternatives and think about what you can cut out from your shopping list. (A great organisation to look into focusing on chemical pollution of all types is CHEM Trust).
  • Get a “Save A Flush” bag to put in your toilet cistern, or upgrade your home to a more efficient toilet. NEVER flush wipes down the toilet and try out reusable alternatives to these.
  • Un-pave, and un-concrete your front and back gardens! Read more here. By changing outdoor surfaces to permeable ones, you will contribute to London becoming a “sponge” city, resilient to heavy rainfall and floods.
  • Think of collective actions we can take to save water and clean up the Thames. For example, check out the great work Thames 21 is doing and get involved! Would you be interested in taking part in a Thames clean-up?

In the next decade, hopefully we will see a healthier river Thames free from fatbergs. Let’s restore the figure of Father Thames back into what it deserves to be: a mighty River God!