A 1.5km section of pipe beneath Grantham town centre will be flushed out when Anglian Water carries out urgent works at the weekend.
Workmen will be on site on Sunday, at the junction of London Road with Wharf Road and St Peter’s Hill.
Temporary traffic lights will be in place from 9am to 3.30pm.
A spokesman for Anglian Water said the works form part of a planned programme of jetting. He added: “The sewers under London Road and Wharf Road have been highlighted as having problems with blockages in the past so we have scheduled an annual clean of around 1.5km of pipe in that area.
“We see around 30,000 blockages in our sewer pipes every year and 80 per cent of those are a result of unflushable items – the most common of these are fats and wipes. These can mix together and stick to the insides of pipes to cause blockages and leaks.
“We would ask all our customers to think about what they’re putting down their toilets and sinks. Please put any left over fat from cooking into your bin or recycling caddy – and all wipes must go in the bin. It costs us £15 million a year to clear blockages like these and that all adds to our customers’ bills.”
A spokesman for Lincolnshire County Council said that by carrying out the works on a Sunday, congestion during the half-term will be avoided.