Christmas menu: Roast potatoes, stuffing and a turkey-berg down the sink

Some of the tons of "fatberg" which have been dug out by engineers in the sewers

Water firms are warning of a build-up of blocked drains in the festive aftermath, as households prepare roast potatoes, buttered greens, basted birds and greasy pigs in blankets for the traditional Christmas dinner.

Yorkshire Water said it was aiming to help tackle problem “turkey-bergs” with its innovative fat-vat scheme, launched in Bradford in 2014, which instead allows residents to collect unwanted oil for use as bio-fuel.

The scheme, run with the Karmand community centre, has collected 3,000 litres of oil from 268 households since it started.

There are plans to eventually expand the scheme throughout the Bradford Moor district, covering up to 6,000 homes.

Duncan Woodhead, from Yorkshire Water, said the project was aimed at changing the behaviour of residents who had been unaware of the risk of “fatberg blockages”.

He added: “The local community in Bradford have really bought into the scheme and since it launched in 2014 there has been only one sewer blockage due to fats, oils and greases compared to 85 blockages between 2011-14.”

Meanwhile, Severn Trent said work to dig out a blockage in Fairfax Street, Coventry, was continuing after several floodings were reported in the area in recent months.

Fat, oil and grease is the cause of more than three-quarters of all of the tens of thousands of blocked drains the firm has to deal with every year.

Severn Trent said its engineers were also preparing for call-outs during the festive period to move more unusual items which in previous years have included a motorbike, a pair of novelty Muppets slippers and underpants.

James Jesic, operations manager for Severn Trent, said: “Everyone loves to indulge at Christmas time and you may find your kitchen turning into a factory, churning out endless festive snacks and treats - but please, please don’t pour hot fat and grease down the sink.

“It might seem harmless when you’re doing it, but that grease quickly solidifies when it cools and sticks to the sides of our sewers forming a concrete-like solid that attracts other debris, eventually causing a blockage.

“With no way through, the waste water backs up the system, coming out of drains and sewers in roads or even into homes - nobody wants a flooded house for Christmas.”

Yorkshire Water said 110,000 tonnes of used cooking oil is disposed of each year by UK households, which could power 110,000 homes with carbon-neutral electricity.