'Concreteberg' The Size Of A Football Field Found In London Sewers

Three sewers in London have been nearly blocked with a "record-busting" concreteberg forming.

The rock-hard mass measures at over 100 metres long and weighs 105 tonnes -- as heavy as a blue whale.

The mass is the largest Thames Water, the company that maintains London's waterways, had ever seen, it said in a statement.

The "industrial amount of solidified cement" is plugging sewers under Goswell Road and Hall Street in the Inner London borough of Islington.

Because the sewers are Victorian brickwork, workers will have to manually chip away at the block, with Thames Water warning of traffic disruptions for at least two months.

Image Thames Water

It is estimated to cost "several hundred thousand pounds" to buy the equipment, such as jackhammer pneumatic drills and high-pressure jets, to completely remove the blockage.

Thames Water operations manager Alex Saunders said the "mindless abuse" of the sewer system is "frustrating".

“This is not the first time damage has been caused by people pouring concrete into our sewers but it’s certainly the worst we’ve seen," he said.

"We’re now doing everything we can to deal with it as quickly as possible, making sure our customers don’t have to suffer because of this mindless abuse of our network.”

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Thames Water is investigating where the concrete came from and how to recover costs.