Power supplies are gradually being restored to premises in the London Bridge area - including Guy's Hospital and Southwark Council's call centre - as the clean-up from Sunday's Tooley Street flood continues.
"EDF Energy Networks staff have worked around the clock at the main substation in SE1 where equipment was damaged following a burst water main," a spokesman told the London SE1 website on Wednesday afternoon. "This affected power supplies to a very localised business area."
"Considerable work has been completed since the flood damage on Sunday and we are now able to supply the full demand of the local area from our main substation. Our work will continue to further secure our power distribution network.
"We are liaising directly with customers in the affected area to arrange the reconnection of their supply to our main distribution network.
"We apologise for the inconvenience caused and assure customers we continue to work quickly and safely to resume normal service."
Guy's Hospital says that full mains supply power was restored at 1.30am on Wednesday and planned operations were able to go ahead as scheduled after two days of disruption.
"We apologise for any inconvenience caused to our patients," says Jon Findlay, director of clinical services,
"We would also like to take this opportunity to thank all staff for their hard work during this incident."
Southwark Council says that limited power is now being provided to the Cottons Centre – where its call centre is based – by both mains and generator power.
"Power is yet to return fully to the Cottons Centre but work continues to test the supply's stability," says a council spokeswoman.
"A strategy to restore business to the Cottons Centre has already begun with some staff already working at Cottons Centre from Wednesday morning. Full operational recovery plans are in review with the council."
The council says that callers to its customer service centre "can expect a reduced capacity ... while work continues".
Meanwhile motorists are still being advised to avoid the Tooley Street area whilst repairs continue.