The Auckland Council's decision to impose mandatory water restrictions is the first in more than 25 years as the city faces its worst drought in history.
The past four months have been the driest on record with storage lake levels dropping below 50 percent for the first time since the 1994 drought.
Today, the Auckland Council's Emergency Committee voted unanimously to introduce the restrictions that will ban residential and commercial outdoor water use.
Auckland Mayor Phil Goff said while it was a stunner of a summer, the city could not have the best of both worlds.
"We all enjoyed a really great summer; it was long, it was fine and it was hot. But the cost of a beautiful summer like that was that Auckland also experienced the worst drought on record."
The months January to April this year have proved to be the driest period in Auckland's history.
The city's water storage lakes - normally three quarters full this time of the year - sit at just 46 percent.
Auckland has been under level one water restrictions throughout the Covid-19 pandemic but the council's water company Watercare had been asking people to conserve water on a voluntary basis.
Goff said the council did not want to add stress to people's lives in the pandemic and there were also physical limitations of enforcing restrictions under the level 4 lockdown.
He said as pandemic measures eased, it was time the city ramped up efforts to conserve water ahead of what was expected to be another dry spell.
"This may be a one in a hundred year drought but that is the past. In the future, with the impact of climate change, this could become the norm but a one in a hundred year exception. We have to plan for that and improve our water resilience."
Goff said the council applied to draw more water from the Waikato River but that was seven years ago and the application was still waiting to be heard by the area's regional council.
He said it had been a frustrating wait and he had since written to the Environment Minister to help fast track the now-critical process.
"That is obviously the most direct and quickest way we can create greater resilience to deal with a new environment influenced heavily by climate change."
For now, the council has unanimously voted to invoke bylaws allowing Watercare to enforce mandatory water restrictions starting on 16 May.
The restrictions prohibit the residential and commercial use of outdoor hoses and water blasters.
They also ban commercial car washes and restrict the watering of sports fields, plants and paddocks.
Watercare chief executive Raveen Jaduram said with no rain in the long-term weather forecast, reducing water use was the only tool Aucklanders had.
"This is very real to us. My innate sense was this can get very bad; which is where we are today. If we don't do enough now and if we don't get the rainfall the coming summer, I just hate... I don't want to even think about it.
Waitākere Auckland councillor Linda Cooper remembers the 1994 drought well. It was a particular crisis for her as she was expecting a baby and had to source a water tank from Hamilton so her newborn's nappies could be washed.
Cooper said today's drought was just as serious and Aucklanders must conserve water - and quickly - to avoid harsher restrictions down the track.
"Like the Covid-19 crisis, we've all managed to follow the rules and keep ourselves safe. We're just asking you to follow these rules and keep our water supply secure."
Watercare head of servicing and consents Mark Bourne said he expected Aucklanders to tell off their neighbours if they see them using water outside their homes.
"I think we will be very reliant on neighbours watching neighbours and I hope in the first instance they just talk to each other and point out the fact we're in a drought and the activity should cease.
"However, if that's not the case, we will have dedicated telephone, web, and social media channels available for people to report."
Anyone flouting restrictions - in force from next Saturday - may face a fine of up to $20,000.