Urgent work to a main sewer under the B2259, by the Royal Oak (pink pub) double roundabout, started today October 3.
The section of Chichester Road is closed as a result, with diversions in place.
A statement, released by Southern Water which is undertaking the work, explained it anticipates ‘the work will take approximately ten days to complete’.
It added: “We recognise this could cause significant inconvenience to our customers and commuters who use the road, and we would like to assure everyone that we are committed to keeping any noise and disturbance to a minimum.”
A spokesperson said the hope is the road could reopen sooner and that the matter is being treated ‘with the utmost importance’.
The road diversions, as agreed with West Sussex County Council and Highways England, are along Rowan Road and the new relief road.
Emergency vehicle and pedestrian access will be maintained at all times.
Southern Water added: “We would like to apologise in advance for any inconvenience caused by our repairs, and we appreciate your co-operation and patience whilst we work to resolve this matter as soon as possible.”