Jet equipment in a transparent tube shifting a melon to demonstrate how fatbergs are unblocked from sewers

The menace of fatbergs: how Southern Water battles festive plumbing challenges

There’s a grim fascination with fatbergs – those vile lumps of fat, oil and grease mixed with wet wipes and other unmentionable material which clog sewer pipes and cause gardens and even homes to flood. 

And during the holiday period, these blockage balls are particularly at large, thanks to the contribution of turkey fat, cooking oils, and even leftover Baileys unhelpfully tipped down the kitchen sink. We’ve even seen wrapping paper and fairy flights flushed down pipes. 

Now, for the first time, Southern Water is lifting the lid on the lengths we are going to destroy these alien objects across our network. 

So, what is the last thing a fatberg will see?  
A super-powered heavy jet sending surges of incredibly fast water at a pressure of 2,500 pounds per square inch (psi) – a thousand times more powerful than the average home power washer. 

To prove this power, our teams staged and filmed a stunt run – akin to the iconic Day of the Jackal sniping scene of 1973 – at a special training zone, and smashed through a watermelon placed in a sewer as if it wasn’t there.  

But a watermelon was easy pickings. This year, our teams used the same equipment to bust a 400lb monster fatberg in Horsham in West Sussex, as well as punch through a range of other big blockages caused by everything from scaffolding planks to cat litter bags.  

Diamond: Too dangerous to turn on hose above ground
Scott Diamond leads 30 sewer jetting teams across our region, working 365 days a year – including the festive period. 

He said,

“We would never turn on the hose above ground – it would be too dangerous.

“The power of the jet is gigantic – the water is travelling at high pressure and several hundred miles an hour.

“That’s why we have the above ground training area.” 

During winter, our jets are being put to good use as we aim to keep our sewers moving, as wet and stormy weather add extra surface and groundwater into our 49,500km sewer network. 

As well as moving around the region to proactively clean and clear sewers, many of the team’s callouts come reactively either from community reports or from information our control room gathers from our 24,000 electronic sewer monitors, which can detect when a fatberg begins to grow – allowing us to respond before a blockage fully forms. 

Saunders: Crews will spend Christmas Day dealing with aftermath
Alex Saunders, our Head of Wastewater Networks, explained,

“Unfortunately, it isn’t just proactive work – all too often the crews will spend Christmas Day dealing with the aftermath of pouring turkey fat or other unflushables down the sink. 

“These crews total more than one hundred people, which will be working over Christmas and New Year, ready to respond to blockages or other damage to the sewer network.” 


News shared by Southern Water, in their own words. Ed