In his statement,, external Mr Gosden said the shortage was the “single biggest water supply incident in our company’s history”.
He said hundreds of Southern Water employees had responded quickly and made a “huge effort”.
“But we failed and we let our customers down,” he said. “With 58,000 properties left without water, opening just one bottled water station on the first day was far from adequate.
“We had a lot of willing employees ready to staff more stations, but we and our partners failed to obtain sufficient quantities of bottled water.
“This left people queuing for hours, in cars or on foot. This fell far short of what the community needed.”