Residents in Skelmorlie, Wemyss Bay and Inverkip have been left without tap water for over eight hours.
Scottish Water were in the process of investigating the cause as residents made personal pleas to the water board over Twitter for supplies.
Councillor Ian Murdoch, pictured, said: "I have contacted Scottish Water and they are working through investigations as to the cause of the problem.
"I have asked for water to be supplied to my constituents.
"They say that they are supplying water to vulnerable people when they request it.
"I have registered a complaint with them as everyone without water is vulnerable, in my opinion.
"I have been informed that someone will contact me."
At 10pm this evening, a Scottish Water spokesperson said:
"Our operatives have located the fault which has been causing the interruption and have managed to resolve the issue.
"The supply will now gradually restore to the area.
"We apologise for any inconvenience caused by this and thank you for your patience
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