They said it had to be done in a “controlled way” to prevent any further issues.
“Hopefully it will not be too much longer until your supplies are fully restored, thank you for your patience and understanding,” they added.
Speaking to the BBC on how the incident has impacted her Christmas, Sam Anderson said her plans to celebrate with a “house full” had been scuppered.
“I’d laid the table already, and it was going to be a really, big celebration for Boxing Day, but we’ve had to cancel all of that,” said the mother-of-two.
Steve Benton, the water company’s incident manager, told the BBC the outage had “impacted our boosters that push water around our network in this area”.
Customers can pick up bottled water from a water station at Solefields car park, on Solefields Road in Sevenoaks.