About 7,000 people were without water Saturday after technical problems arose while pipes were replaced at Netley Mill Water Treatment Works.
The water supply is starting to return, but Councilor Liz Townsend said people were “annoyed” and added “the service is not fit for purpose” after multiple outages were reported in the area this year.
Lib Dem’s representative for Cranleigh and Ewhurst said: “We are no strangers to water loss. We have had supply disruptions in February and July and one village has had three disruptions this year alone.
“This is happening more and more, and the service is not fit for purpose, and residents are rightfully getting very annoyed.
Ms Townsend added: “Thames Water is intended to provide water to vulnerable people, but that system broke. I got messages from people who had not been given water.”
A Thames Water spokesperson said: “We are very sorry if you have no water or low pressure. We know this has been incredibly disruptive during the very hot weather.
“Supplies are gradually starting to return to the area and will continue to do so throughout the day. As they return, you may experience low water pressure at first, especially if you live higher up.
“Our engineers are busy identifying and unblocking air bubbles in the system so that supplies return to normal as soon as possible.”
Three bottled water stations remain open at Cranleigh Leisure Center in Village Way, Surrey Hills Business Park and Gomshall Village Sports and Social Club.
The affected zip codes were GU5, GU6, RH4, RH5 and RH12.