Inside Southern Water's 'super sewer' keeping the sea off Brighton safe to swim in

How do we solve our region's sewage issue?

It's one of a number of questions we'll be asking as part of ITV Meridian's 'What's In Our Water' special programmes.

Just last week, the Environment Agency criticised water companies over their "unacceptable" performance on sewage spills last year.

The regulator said five out of nine companies in England were rated as "requiring improvement" in its annual report.

There were 47 serious pollution incidents - up from 44 in 2022. Four companies - including Southern Water - caused 90% of those incidents.

We began our investigation, venturing into one of the oldest sewers in the country - the Victorian system below Brighton.

These sewers date back to the 1870s, built by hand in an incredible feat of engineering.

Still in use, despite their age, they became a blueprint for many that followed - raw sewage flowing through them and then pumped into the sea.

That didn't change until the 1990s.

"This overflow sewer is still performing its job to this day," Simon Judd of Southern Water said.

"With every heavy rainfall it would overflow and then come out through outfalls onto the beach.

"Years later, Southern Water realised that's unacceptable and something had to be done. That's when we constructed a storm tunnel under Brighton beach."

The result was a 'mini-super sewer' constructed below Brighton and Hove in the 2000s - fully operational since 2012.

The super sewer cost more than £40 million pounds and is designed to withstand all but a one in 50 year storm.

Few ever realise its there, its entrance hidden under a small kiosk on the promenade.

Yet, because of it, Southern Water say they've had no sewage discharges in the Brighton area for twelve years - despite popular beliefs.

So if it has solved the issue in this area, why not elsewhere? Why not in Whitstable? Why not in Worthing?

"These projects are massively expensive and they are not good for the environment," Alex Saunders of Southern Water said.

"So for sure, they can play part of solving the problems, but they're certainly not the solution."

Yet the sector faces a national crisis after years of under-investment combined with ageing infrastructure, a growing population and wetter conditions caused by climate change.

Alan Lovell, chairman of the Environment Agency, said: "This is unacceptable. The results we see are, yet again, simply not good enough."

Since being privatised in 1989, its thought water companies paid out more than £70 billion in dividends - while presiding over leakage and pollution failures, including unknown quantities of untreated sewage pouring into coastal waters and rivers.

Mr Lovell said the culture within some firms "can also perpetuate poor practices" and warned that the regulator will not take "bad weather" as an excuse for poor environmental performance.

Hastings town centre was seriously flooded twice last year, after its sewers were overwhelmed.

Businesses and homeowners were left counting the cost - with Southern Water under fire once again after its systems were caught out by high tides and heavy rain.

60mm of rain fell in 24 hours with the drainage overwhelmed in October - as it was in January.

The company organised help for those affected, but many were left angry and upset.

One newsagent told us the floods left his business on the brink, amassing up to £50,000 in damages and lost trade.

Following repeated incidents, he can't get insured.

"It was up to my thighs following the main burst, water gushed in within seconds," Dhaval Patel said.

"Rather than being helped, I felt insulted. It's not the value I expected. If it happens in the future, I'm doomed."

Experts say the lack of capacity at wastewater treatment plants means companies are releasing sewage into waterways even during dry periods.

A study by Imperial College London found almost 80% of sewage spills are attributable to insufficient capacity - a lack of investment in infrastructure to keep up with demand.

Meanwhile, the Environment Agency has slashed the number of homes it expects to protect from flooding over the next five years as higher costs have forced it to scale back.

A National Audit Office report said the agency had pledged to protect 336,000 properties from the risk of flooding by 2027 – but that this had been cut to 200,000 – a reduction of 40%.

We spoke to Ian Nunn from the Environment Agency at an emergency flood depot in Rye.

"What we're seeing, I think, is more significant rainfall events, higher tides, bigger storms. And fundamentally, we cannot protect everyone from flooding forever," he told us.

"The biggest challenge is definitely climate change. Without a doubt."

Mr Lovell added: "We know that with a changing climate, the country is going to experience more extreme weather patterns, increased rainfall and more rapid drought.

"Water companies must ensure that assets are resilient enough to withstand these challenges."

Environment Secretary Steve Reed called last week's findings "shocking".

"For too long, water companies have pumped record levels of sewage into our rivers, lakes and seas. This Government will never let this happen again."

The new Government has announced plans to crack down on water firms, including tougher fines for pollution incidents and ensuring money is invested into infrastructure rather than paid out in bonuses.

A spokesperson for Water UK, the sector's trade association, said: "While results show overall water company environmental performance has improved, it is clear there is more to be done.

"The performance of some companies, as they acknowledge, is not improving fast enough and pollution incidents remain too high.

"Water companies have proposed investing a record £105 billion to secure our water supply in the future and stop sewage entering our rivers and seas.

"Ofwat needs to approve these plans in full as any less will put critical improvements at risk."

Victorian sewers, often blamed by politicians, were never the cause of our sewage spills, experts say - the vast majority are far more modern.

It's thought that less than 12 per cent of the sewage network in England and Wales was built in the 19th century.

The majority of the network was instead built in the years before privatisation, with approximately a fifth constructed during the 1960s and 1970s.

Yet change is now desperately needed - and if not £40m super sewers like the one under Brighton, now estimated to cost more than £100m to build, fresh ideas need to come on line, and fast.

You can catch the full report on Southern Water's 'super sewer' on ITVX.

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