£12m for sewer

A MILE-long underground sewer is soon to be laid through central Lewes but Southern Water is hoping that it won't be necessary to dig up large stretches of road, causing months of untold traffic misery.

The plan is to sink shafts in convenient areas and then drive the new 4ft diameter concrete sewer through the chalk with drilling machines and labourers.

They will be working in harsh and wet conditions between 15ft and 25ft below ground level.

Lewes will be one of the first towns in the south-east to undergo such a major sewerage scheme.

Including preliminary works, the huge operation is expected to cost in the region of 12 million and take a year to become operational.

It will supplement a whole series of Victorian sewers in the town, most of which are between 12 inches to 18 inches in diameter.

The new sewer will reduce the occasional release of stormwater and sewage from outfalls into the Ouse, the Winterbourne and Pells wetland.

And it could also store more stormwater during periods of heavy rain, lessening localised flooding from sewers into homes in areas like Talbot Terrace and Friars Walk.

Southern Water officials were anxious this week to make it clear that the new sewer will not solve the wider problem of river flooding.

Water business manager Wayne Middleton said: 'In Lewes there is the problem of diluted sewage getting into the Ouse and other local watercourses such as the upper Pells and Winterbourne after heavy rainfall.

Victorian

'That is because there is a combined system of sewers, some Victorian, in the old central part of the town which means that a single pipe takes away both rainwater and sewage for treatment.

'During heavy storms these sewers are simply not big enough to cope with the increase in flows from both sewage and rainwater, so flows have to be released into local watercourses.

'By constructing a single larger sewer and closing off overflows, and building just a single overflow to release stormwater into the Ouse near the end of Railway Lane, we can substantially reduce this problem and meet water quality standards.'

Site investigations are currently being carried out in Lewes by contractors Black and Veatch/Costain with a series of boreholes being dug over the next few weeks to detemine ground conditions.

Lewes is almost entirely made up of chalk and silt. Contractors are looking for solid chalk through which to drive the sewer.

Work has already started in the magistrates and NCP car parks and more will be dug in Court Road car park, Pinwell Road, railway station car park, Friars Walk, Tanners Brook, Dumbrell Court, High Street, Western Road Primary School, Phoenix Place, Court Road, Garden Street and Southover Grange.

* The new sewer will run essentially from the Pells to Pinwell Road via Brook Street and Eastgate Street.

The work does not affect the Cliffe area which has its own sewerage system.