Raw sewage poured into east London rivers for thousands of hours in 2020

The River Roding in Redbridge

The River Roding in Redbridge - Credit: Ken Mears

Raw sewage flowed into waterways for more than a quarter of 2020 in some parts of east London, figures have revealed.

Under law, discharges of untreated effluent are only permitted in exceptional circumstances. 

However, constituency data from the government’s 'consented discharges to controlled waters with conditions' database show the practice is far from exceptional. 

The data was collected and published in the form of a map by the Rivers Trust, an environmental charity. 

Redbridge’s Ilford South suffered worst, with untreated effluent flowing into waterways in for more than 2,569 hours – nearly 30 per cent of the year.  

Further east, Dagenham and Rainham experienced 113 spills, with a total duration of 2,143 hours, while Hornchurch and Upminster saw 78, lasting 1,022 hours.  

In Newham, East Ham was the site of 117 spills, lasting 1,188 hours in total.  

Raw sewage flowing into the Lea Canal near Queen Elizabeth Olympic Park recently caused a public outcry in the borough. 

Poplar and Limehouse recorded a relatively high number of spills – 247 – compared with the hours of spillage, which was 334. 

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Ilford North and Leyton and Wanstead both experienced more than 500 hours of spillage. 

The sewer system is built using a combined drainage model, meaning stormwater drains and household plumbing goes into the same system. 

Anneka France, a data analyst at the Rivers Trust, explained: “In the Victorian era, they realised if a pipe becomes overwhelmed and reaches its maximum capacity it would just back up and flood people’s homes and businesses with sewage.”  

Overflows were designed as release valves in this system, triggered automatically when the system reaches a certain threshold, but discharges are only permitted in circumstances such as extreme rainfall. 

But according to Anneka: “A lot of these sewage overflows are discharging even when we haven’t had an extreme weather event.” 

She blamed a lack of investment from water companies, along with population growth, urban creep and climate change, and suggested a mix of improved infrastructure and nature-based solutions to tackle the issue. 

Thames Water, which is responsible for most of the public water supply and waste water treatment in London, did not respond to a request for comment.