Taps unexpectedly ran dry in Hokitika for two hours yesterday after a contractor mix-up.
Westland District Council assets and operations manager Vivek Goel said Westroads was undertaking planned work on the Kaniere water supply at the time.
"However, someone accidentally shut off the main supply to Hokitika, which caused the town to run dry."
The mistake left Hokitika residents and businesses without water from about 11am and the council was inundated with phone calls.
Glow Hairdressing owner Liz Scott said the outage was an "unexpected inconvenience" but staff handled it well.