'Unexplained emptying' causes 200,000 litres of water to disappear from Glenorchy supply

Where has 200,000 litres of water disappeared to from Glenorchy?

That is the question staff at the Queenstown Lakes District Council have been trying to answer for two days.

On Sunday the council reported an "unexplained emptying" of the town's water reservoir sometime in the afternoon or evening.

Council communications manager Michele Poole said "an estimated 200,000 litres of water was drawn down in a short time", which almost resulted in the entire town running out of water.

"Put it another way, that's 200 tonnes of water," Poole said.

Engineers were able to reduced the "massive outflow" from the reservoir, with the town's water supply being maintained by a bypass direct from the bore to the town, but were still trying to trace the cause.

"We do know that it wasn't a burst main or infrastructure failure, because the outflow stopped around the time that we publicised the problem and [there] was no trace of large amounts of water ponding anywhere," Poole said.

It was also not believed to have resulted from developers working in the area.

"What we don't know is who was responsible or what they were using the water for," Poole said.

"This sort of draw down you can't attribute to people watering their lawns at the same time.