Hastings borough councillor Becca Horn told BBC Radio Sussex that the prospect of Christmas without water was “just really unthinkable” and she was “really hoping that it doesn’t get to that point”.
John Bownas, of the Hastings Business Improvement District, said he had “a degree of confidence that a lot of people don’t share that this will get sorted”.
He said it was still “business as usual” in the town while the water supply remained on.
Ms Dollimore said she was “really angry about the impact this could have on our pubs, our restaurants, our hotels”, but that “Hastings is open for business, we have got a water supply”.
The main had burst multiple times in recent years but only once led to a supply failure, according to Mr Bownas.
Southern Water said a £50m project to replace the 5.6 mile (9km) pipe over three years had been brought forward to begin in January.