The Mayor of London, Sadiq Khan has today revealed shocking new analysis showing that between April and December 2023, Thames Water released sewage into London's waterways for

6,590 hours, 11 minutes and 54 seconds – a five-fold increase on the same period the previous year. 

In just six days, between 25 December and 31 December 2023, sewage was dumped across the Thames Water network for 128 hours and 12 minutes, equivalent to 18 hours every day. These discharges include both treated sewage and overflows of untreated sewage and storm water into rivers during high rainfall. The new analysis comes from published Thames Water data which monitors discharge from 118 sites across the Thames Water network feeding into 33 rivers and waterways.

In a letter to new Thames Water CEO Chris Weston, the Mayor highlighted the scale of the challenge that decades of under investment has led to London now having no healthy rivers. Sadiq urged Chris Weston to urgently get to grips with the problem and asked for reassurance that the organisation “will fulfil its obligations on environment including cleaning up our rivers and tackle pollution discharges”. The Mayor gave the example of the River Wandle – which was the last London river to lose its “good” status in summer of 2023 – which is now set to have sewage spills continuing until at least 2035.

In addition to the poor level of service Thames Water has been providing for Londoners, the Mayor is also calling on ministers to do more to get a grip of the crisis.

 Sadiq is calling on the Government to:

Develop a plan to guide Thames Water back to strong financial health in a way which doesn’t delaying the cleaning up of London’s rivers

Deliver the essential water network upgrades that are needed, while protecting Londoners from increased bills.

Introduce tougher legislation that forces water companies to end sewage discharge into rivers. This should include tougher penalties for water companies. 

Since 2016, the Mayor has taken bold action to improve the environment in London. This includes expanding the ULEZ London-wide to ensure all Londoners have the opportunity to breathe clean air, planting over 500,000 trees to help make the capital greener and healthier for everyone, working closely with boroughs to bring beavers back to the city and, investing £1.4 million to clean up local rivers and improve habitat for wildlife.

The Mayor has also achieved his 10km river restoration target early, with work undertaken to improve river and stream habitats in the city. London is also leading the way in innovating the creation of Sustainable drainage systems (SuDS), working in collaboration with community groups, schools and boroughs to deliver a variety of different projects to slow the flow of water across the capital.  

The Mayor of London, Sadiq Khan, said: “London’s rivers are the arteries of our city. Frankly the current state of some of our rivers is appalling and only getting worse. Thames Water urgently need to up their up their game, and get a grip of the situation. At the same time, ministers are standing by and letting more and more dirty sewage flow into our rivers. We need tougher legislation that forces water companies to act as a matter of urgency.

“While we’re making huge progress cleaning up London’s air and much of the capital’s environment, it’s a scandal that levels of sewage in our rivers are increasing at the same time.”

James Wallace, CEO of campaign group, River Action said: “With the London Mayoral election just a few weeks away, it is essential that the public sees a genuine commitment to urgency and leadership from City Hall to tackle the dreadful state of the River Thames.

“For decades Thames Water has got away with polluting our waterways, wasting drinking water and threatening the health and livelihoods of Londoners with impunity.

“We welcome political leaders committing to holding profiteering water companies and the failing Government regulators - the Environment Agency and Ofwat - to account.

“As cyclical floods and droughts worsen and the impact of aging infrastructure and population growth hit the most vulnerable and our precious wildlife, we need the Mayor of London to prioritise water quality and supply alongside other essential services.

“We hope the Mayor will not rest until Thames Water and the regulators are properly scrutinised and emergency plans are in place to secure London’s lifeblood, freshwater.”

Liz Gyekye, Communications Manager at Thames21, said: “Thames Water has underinvested in their sewerage infrastructure for many years and desperately needs to modernise its network to prevent unacceptable sewage spills.

“London-based NGOs, including ourselves, are urging Thames Water to expedite the implementation of 357,000 rain gardens across London by 2040, rather than the proposed timeline of 2050 outlined in Thames Water's current business plan.

“This accelerated action is imperative to protect and restore London’s rivers from the ravages of sewage pollution as well as preventing the effects climate chaos on Londoners, as rain gardens help to prevent sewage pollution by holding flood water and helping to reduce the speed of it entering the sewerage systems.

“We urge them to significantly upscale their ambition and effectiveness to protect and restore London’s rivers for people and wildlife.”

Alison Debney, Conservation Lead at ZSL said: ““We are pleased to see The Mayor of London standing up for our rivers. Securing the level of investment needed to stop pollution, pull rivers out of concrete and restore habitat will be transformative for London. It will make our city richer in nature, more resilient to the impacts of climate change and a more enjoyable place to live.” Photo by Kaihsu Tai, Wikimedia commons.