South East Water says it has repaired the burst main which left Hailsham residents high and dry on Sunday evening (June 11).
Some properties in Hailsham were left without water.
Incident manager for the company Desmond Brown said a 10 inch diameter pipe burst leading to flooding and the closure of the Diplock roundabout on the A22.
A diversion was put in place while the carriageway was cleared of mud and debris as the repair was carried out.
Mr Brown said, “Our teams worked through the night to repair the burst main and restore drinking water supplies to normal.
“It was a very complex repair needing specialist replacement parts, but our teams worked as quickly as possible.”
Mr Brown said technicians changed the flow of water around the network to avoid disruption to supplies where they could.
South East Water could not confirm how many customers were without water or for how long.
Customers in Hailsham have experienced water supply issues in the past, most notably when a large pipe burst two years ago.
According to South East Water, the latest burst was not on the same section of the network as in 2015, but reassured customers that action would be taken to try and prevent a repeat of the problem.
A spokesperson said, “We would like to thank our customers for their patience and apologise for any inconvenience caused.”