Auckland Mayor Phil Goff says the city's water situation is looking worse than it did before the drought of 1993/4, but it's not yet time to panic.
From May 16 Aucklanders will be told to reduce their water usage in order to buy a bit more time, but ultimately what the city needs is rain.
"We all had a fantastic summer - it was the longest and the finest and the driest on record. And that was the problem," Goff told The AM Show on Friday.
"We ended up from January to April with the driest months ever in recorded history of Auckland. That means we're getting through the worst-ever drought."
Lakes at this time of year are normally 76 percent full - right now they're at 46 percent.
"We're not yet in crisis, but we are facing a critical situation if the rain still doesn't come," said Goff.
"It's not yet a crisis, but if you look at the graph, the rain level and the lake level is lower than at a comparable time in 1993, 1994. We don't know what the weather is going to deliver us. NIWA says it will maybe be drier than normal - we're not quite sure what that means yet. What we're saying is right now is if we take action now, we won't have to take more urgent and more drastic action later."
In May 1994 Auckland's water supply reservoirs dropped to 32 percent.
"The drought was broken by a relatively wet second half of 1994, which, combined with significant water savings, resulted in reservoir volumes reaching 95 percent by the end of 1994," a University of Auckland study from 2004 reads.
At this stage, Goff and Watercare - the council-controlled organisation that looks after the city's supply - say all we need to do is use about 5 percent less water.
"We want Aucklanders to know this is serious," said Watercare CEO Raveen Jaduruam. "We're in a serious drought. Is it so serious that you have restrictions? Yes."
Those restrictions include not washing your car or house, or watering your lawns, as well as watering sports fields and paddocks.
If Aucklanders don't save enough and it fails to rain in any significant amount, the restrictions may get tighter.
"There's always some element in society who do not respond well to voluntary calls - we found that with COVID-19," said Jaduram. "Most Aucklanders are already responding well."
Goff is optimistic it won't come to that, saying Auckland gets its water from more sources than in 1993/4, including the Waikato River.
"We will always have some water. But the lake level will keep falling, and the lower it falls the more urgent the action that needs to be taken to restrict water use.
"There will always be drinking water, for hygiene, for basic needs and emergency services - but at the worst extreme, we'd have to look at putting real restraints on the water-hungry industries that we have operating in Auckland. Having come through COVID-19, we don't really want to do that."
A full list of restrictions can be found on the Watercare website.