The pipes on Kings Highway in SE18 burst, leaving residents without water.
Thames Water said it was aware of the issue and its team worked overnight to fix the pipes.
Water tankers were brought in to help keep the supply going for as long as possible.
The essential repairs were completed by 8am on October 20, but Thames Water warned that it could take a couple of hours for water pressure to return to normal.
It also warned that the water may look slightly different as it returns.
A Thames Water spokesperson said: “We’re sorry if your tap water isn’t running as normal at the moment.
“We’re aware of two burst water pipes in the Kings Highway, SE18 area, and our specialist team is on site working to fix it as quickly as possible.
“Both repairs will be carried out overnight.
“Water tankers are in the area to support, adding extra water into the pipes to keep as many people in supply as possible while we carry out the repairs.
“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.
“If you or someone you know needs a little extra support, our free Priority Services Register can help us to understand your situation so we can take it into account as best we can.
“We’ve completed the essential repairs to the burst pipe that was affecting your water supply.
“We’re sorry for any inconvenience this may have caused.
“After an issue like this, it can take a little time for water pressure to return to normal across the network.
“Depending on your location, this may take a couple of hours.
“You may also notice that your water looks slightly different as the water returns.
“This is normal, but we’re here if you’d like any advice or support.
“Thank you for your patience and understanding.”
