Up to 15 properties are expected to shortly lose their water supply while work is carried out on the damaged main.
An inspector is in the area talking to those who will be affected and bottled water will be delivered.
A Southern Water press officer said: “We do not envisage having to close the road and we hope to be able to complete the repair this morning. We apologise for any inconvenience.”
A spokesperson from Stagecoach, Marine Parade, Worthing, said buses were not picking up on the way to Lancing and there was a slight diversion avoiding South Street, Worthing.