"Panuku would like to thank the member of the public for bringing it to their attention."
Watercare said earlier today that Aucklanders used 415 million litres of water in the past 24 hours, down 35 million litres (8 per cent) from the normal 450 million litres.
The company said more savings were needed to reduce usage to the target of 400 million litres a day to avoid the need to let partially treated water into the water supply, which would trigger a warning to boil water before drinking it.
A spokeswoman said the figures included commercial, industrial and institutional users which together use 25 per cent of Auckland's water, compared with 56 per cent used by households. The other 19 per cent is either lost from water pipes or pumped out through the Papakura bulk supply network.
"Our largest users have all been contacted and briefed personally. The message to them is consistent with all of Auckland: to please save water," the company said.
Kimpton said Auckland Council had switched off all fountains that use reticulated water and would be switching off fountains and water features which use recycled water.
"We have also begun asking customers to take shorter showers and generally use less water in our bathroom facilities," he said.
"We are also stopping hosing around pools. Slides and water features reuse water from the pools so do not need to be shut off.
"We have prepared water saving messages to relay to council staff on Monday to encourage them to reduce water use at work and home."
The region's hospitals, which are among the biggest users, said they could not save much water.
"Because we are an essential service, we have to be very careful to not interrupt any hygienic practices such as bathing patients, which we don't take long with anyway, and things such as handwashing," said Counties-Manukau District Health Board spokeswoman Lauren Young.
One of the region's biggest industrial water users, NZ Steel at Glenbrook, said it had its own water supply so it was not affected by the Watercare restrictions.
Watercare said it would only issue a warning to boil water "if Aucklanders continue to consume more water than we are able to treat for a sustained period".
"We will not issue a boil water notice without giving prior warning," the company said.
"At a minimum, we will give 12 hours' notice."