UPDATE:
Water has been restored to Karragarra, Macleay and Lamb Islands as of about 11am.
Water supply is back on at Karragarra, Macleay and Lamb Islands, with a Redland City Council spokeswoman warning that water pressure will build as pipes fill.
"Seqwater advises the water is safe to drink and does not require boiling," she said.
"Residents and visitors at Karragarra, Macleay and Lamb Islands are asked to let their taps run for two to three minutes before using water after a main pipe was replaced overnight.
"There may be some air in residential pipes or some discoloured water when residents first turn on their tap.
Thank you to Seqwater and council crews who replaced the burst pipe and island ambassadors, rural fire service, SES, ferry operators and community members who provided invaluable assistance during this emergency incident."
She said any inquiries should go to Seqwater on 1300 737 928 or visit the Redlands Coast disaster dashboard website (disaster.redland.qld.gov.au)
9.20am:
Water to be restored to Southern Moreton Bay islands by mid-morning
Seqwater advises water will be progressively restored to Karragarra, Macleay and Lamb islands on Redlands Coast this morning.
A burst water main on Karragarra Island was successfully replaced overnight and drinking water is being restored to island residents. All residents should have supply back by mid-morning today.
The water is safe to drink. Treated water samples will be taken at various points along the network and laboratory tested to ensure there is no concern for public health.
There may be some air in residential pipes or some discoloured water when residents first turn on their tap.
Residents are advised to let the water run for 2-3 minutes to clear. The tap water will be safe to drink.
Thank you to community champions, Rural Fire Service, SES, ferry operators and community members for helping to get information out to island residents and thanks to Seqwater and Council crews for their work.
For more information, call Seqwater on 1300 737 928 or visit the Redlands Coast Disaster Dashboard website at disaster.redland.qld.gov.au.
Water has been cut or supplies reduced to some parts of Macleay, Karragarra and Lamb Islands due to a burst Seqwater trunk main in East Street at Karragarra.
Seqwater and Redland City Council crews are at Karragarra to investigate the cause.
The first step is to drain ponding around the burst main so crews can inspect the pipeline. This is expected to take most of the day.
An Seqwater spokesperson said water pressure would need to be further reduced late this afternoon to allow inspection of the pipe.
For some areas, this might result in low or no water pressure.
Seqwater will determine the repair work required once the pipe is assessed.
The aim is to undertake the repair work tonight, meaning supplies will be cut from 7pm.
A Redland City Council spokeswoman said there was no need to boil drinking water.
"Currently, the water supply to Karragarra, Macleay and Lamb islands remains safe to drink," she said.
Residents are advised to begin preparing for an overnight water shutdown by:
# filling suitable containers with drinking water and storing them in the fridge
# store water in the bathtub that can be used for toilet flushing
# plan to shower or bath early this evening or later tomorrow morning.
"We will provide more details and updates as information becomes available," the Seqwater spokesperson said.
Maintenance works continue on the mainland in the Alexandra Hills area to ensure continuity of supply.