Cornwall sewage leaks by South West Water MAPPED

Two-year-old Oli Kinshine from Falmouth, out campaigning to protect our water
-Credit: (Image: Greg Martin / Cornwall Live)


While in Cornwall the focus has always been on foul sewage leaks into the sea, the scourge runs much deeper than that. The same rules that allow South West Water (SWW) to pour millions of litres of raw sewage into our swimming waters also let it do the same into our rivers and from pumping stations.

And while we all know where the sea is - and the main waterways like the Rivers Camel, Fal, Tamar and Helford River - there are dozens of smaller tributaries being polluted with faeces and urine and other waste for thousands of hours a year. And then there are the hidden treatment works we don't even know are practically in our backyards and spewing sewage into our midst.

Now we have mapped all of the leaks from SWWs combined storm - or sewage - overflows (CSO). These are the gadgets that combine household sewage and land run-off that it is legally allowed to pour poo from when they get overwhelmed, usually after heavy rains.

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As bad as we think it is, it turns out that SWW is only towards the bottom of the league table of the worst offending water firms in terms of CSO spills in 2023. However it is second worst in terms of the overall duration of spills, in total number of hours (SEE interactive table lower down in this article).

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But the sheer number of outlets in Cornwall is staggering - even more so the hundreds of leaks and tens of thousands of hours of leaks. They include CSOs, emergency overflows (EO) and pumping stations (PS) all over Cornwall, on the coast and inland.

You can see how long the overflows near you were open our interactive map of

As Labour plans to crack down on water companies, their bosses could face jail-time under sweeping new laws proposed by the Government to reduce the amount of pollution of England’s waterways. The Water (Special Measures) Bill, introduced to Parliament on Wednesday, will hand new powers to Ofwat and the Environment Agency to take action on companies damaging the environment and failing customers.

Under the Bill, harsher penalties for law-breaking will be introduced, including jail sentences of up to two years for executives who fail to cooperate or obstruct Environment Agency and Drinking Water Inspectorate investigations.

Years of under-investment by the privately-run firms combined with ageing water infrastructure, a growing population and more extreme weather caused by climate change have seen the quality of England’s rivers, lakes and oceans plummet in recent years.

Sewage spills have contributed to a situation in which no single river in England is considered to be in good overall health, and beauty spots including Windermere in the Lake District have been polluted.

Annual data from the Department for Environment Food and Rural Affairs shows how often each water company has used storm overflow to empty excess rain water along with sewage into the country’s waterways, and for how long those overflows were open.

See where SWW places in terms of both number and duration of spills in this interactive chart

Water companies in England spilled from storm overflows into the country’s waterways 464,056 times in 2023. That’s the equivalent of 1,271 times a day. Those spills lasted for a combined total of more than 3.6 million hours. That’s the same as a single overflow pipe running for 412 years non-stop.

United Utilities, which covers the North West of England, had more spills than any other water company in England last year. A total of 656,014 discharges were made from the company’s storm overflows into the region’s waterways in 2023. Those lasted a combined total of 97,537 hours, which is also the highest of any water company in the country and equivalent to a single overflow pipe running for 75 years.

Yorkshire Water’s storm overflow discharges lasted a combined total of 77,761 hours (59 years), Severn Trent Water’s lasted 60,253 hours (50 years), and South West Water’s lasted 58,249 hours (61 years).

See SWWs number and duration of spills in this interactive chart - and compare to other companies

Environment Secretary Steve Reed said: “The public are furious that in 21st century Britain, record levels of sewage are being pumped into our rivers, lakes and seas. Under this Government, water executives will no longer line their own pockets whilst pumping out this filth. If they refuse to comply, they could end up in the dock and face prison time.”

A Water UK spokesman said: “We agree with the Government that the water system is broken. Fixing it requires the Government to deliver the two things which it has promised: fundamental regulatory reform and speeding up investment.

“Ofwat needs to back our £105 billion investment plan in full to secure our water supplies, enable economic growth and end sewage spilling into our rivers and seas.”

Mike Keil, chief executive of the Consumer Council for Water (CCW), said: “Our research shows consumer trust in the water sector has been badly fractured by concerns about the environment, which is why we welcome the measures laid out by the UK Government to ensure there are more serious consequences for water companies if they harm our rivers, lakes and seas.

“These changes will complement the work we’re already doing to help transform the culture of water companies, so they are focused on providing the best possible service for their customers.”

Gary Garter, GMB union National Officer, said: "This is the first step to cleaning up the UK's rancid waterways - as well as the whole sector. GMB members want to see rivers and waterways restored to good health.

"For too long water companies have used public money to pay big bonuses and huge dividends, but failed to deliver the investment we desperately need.

"Tougher regulation is welcome but the Government must fundamentally overhaul the way water companies are run. They must be accountable not only to ministers and regulators but unions, consumers and environmental groups too.

"The unaccountability of water companies must end."

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