ENGINEERS have embarked on a £250,000 project to strengthen Bolton's ageing and decaying sewer system in a bid to prevent a possible future collapse.

work began this week on roads in and around the town centre and is set to continue until the end of the year.

Bolton Design Group, part of the council, has been contracted by North West Water to undertake the work which they say is not being carried out as a matter of urgency but is part of a planned programme.

But a NWW spokesman said: "If the Victorian sewers were left any longer they would degenerate further and possibly collapse altogether in some parts which would result in very disruptive emergency work."

Recently council planners were forced to restrict heavy goods traffic on Bradshawgate because a tunnel running underneath it, another legacy of the town's Victorian past, may collapse.

Council engineer Steve Walsh said the work was being carried out to "pre-empt the worst case scenario" of a sewer collapse.

Work has already begun on Gilnow Road and will continue on Tudor Avenue, Chorley Street, Saint Helena Street, Back Gilnow Street and Park Street in the months ahead. In total 651 metres of sewer will be repaired.

But both the council and NWW have pledged that disruption to traffic and residents will be reduced to a minimum because most of the repair work will be carried out below the road's surface.

Using relatively new techniques water will push a liner tube through the sewer which then hardens and sets into place on the sewer wall.

NWW project manager Joanna Matzen said: "This method is relatively new and the benefits for customers are improved sewers in double-quick time with minimal disruption."

But Mr Walsh added that temporary traffic lights would have to be installed in Gilnow Road, Tudor Avenue and Chorley Street.

"The disruption to motorists really will be minimal," said Mr Walsh. "There may be slight delays in and out of Bolton town centre when we have to remove a manhole cover but much of the work is being carried out in back streets."