A major incident was declared by police as Lee High Road flooded near Lewisham on Saturday night.
Some people had to be moved to a temporary shelter while many living in surrounding areas have been left without any water supply.
Thames Water has apologised and said the repairs were "complicated".
The coach remains trapped in the sinkhole.
London Fire Brigade (LFB) said it had assisted 40 tourists from the stranded coach which was carrying 90 people, while 40 local residents had to be evacuated from their homes.
A Lewisham Council spokesman said the tourists were taken to a local community centre but another coach was arranged so they were able to continue their journey without needing to stay the night.
The spokesman for LFB said six fire engines had been sent to the scene which had also affected about 50 shops and businesses.
Thames Water said the burst 60cm (24in) pipe had affected supplies for people living in large parts of south-east London, including those in SE3, SE10, SE12 and SE13.
The water company said it had "successfully re-routed the water" as the pipe could not be repaired until the coach was removed but that "some properties" were still "experiencing problems".
Blackheath resident Rob Carrick said he had been without water since Saturday night.
Foyeg Ahmed Kazi, who runs a restaurant in Lee High Road, said he had been told to remain closed until repairs had been made to the pipe, which he said had cost him a lot of money.
About 3,000 homes were at one point thought to be without a water supply and bottled water was being made available at a number drop-off points.
At about 18:00 GMT on Sunday, Thames Water tweeted it had "completed some works on the network" and those affected should see their supplies returning to normal.
Lee High Road remains closed, with police warning it will be shut "for some time".
A coach carrying dozens of tourists became trapped in a sinkhole when a water main burst beneath a busy south-east London road.