In a statement, the company said a burst main on Rouse Gardens, SE21, is affecting tap water supplies, with disruption also being reported by customers living in SE21 (Dulwich) and SE27 (West Norwood).
Thames Water confirmed specialist repair teams are currently on site and working to restore water supplies.
In a statement on its website, the company acknowledged the disruption caused and apologised to residents.
In an update, Thames Water said: “We know how disruptive it is if you lose your water supply, so we’ll work hard to get things back to normal as soon as we can.”
Residents who require additional support during the disruption are being encouraged to sign up to Thames Water’s free Priority Services Register.
Thames Water has said a further update on the situation will be provided on its website by 2pm today (January 4).
