Auckland's consent to take extra water from Waikato River will be fast-tracked, Environment Minister David Parker has announced.
Auckland Council had called for the government to consider its water company Watercare's application to the Waikato Regional Council as part of its Covid-19 Recovery Bill projects.
Parker said the government was "calling in" the application to take an extra 200 million litres a day from the lower reaches of the river, meaning it would not have to go through the full RMA process.
The water would be used for drinking and other municipal uses.
Parker said future sources of drinking water for Auckland is a matter of national significance.
"The application obviously affects Auckland, but also other activities in the Waikato and the river itself," he said.
Auckland has been facing its worst drought in 25 years, receiving less than half its normal rainfall between November 2019 and May 2020.
Watercare has had a consent to take 150 million litres a day from the Waikato River since 1998. As a result of progressive upgrades to their infrastructure the full 150 million litres has been able to be used since 2019.
Its application for 200 million litres was filed seven years ago, with the expectation that the additional water would be needed from about 2030.
Watercare had already this month used emergency powers under the Resource Management Act to draw a further 15 million litres of water a day from the river.
Aucklanders had been asked to keep water usage down, and outdoor water restrictions were put in place for the city for the first time since the 1993/1994 drought.
With Watercare aiming for below 410 megalitres (million litres) a day usage in June, Jaduram said the city had averaged about 405 megalitres.
Watercare has also been looking at further options for water storage, including spending $57.5 million to recommission the Hays Creek dam in Hūnua, which was mothballed 15 years ago.
It also planned to have a new reservoir up and running by August on the outskirts of Pukekohe which could handle 50 million litres of water.
Waikato iwi have objected to Auckland Council's bid to more than double the city's daily take from the waterway.
Waikato-Tainui have said the fast-track application was never raised with them, and have criticised the move to include it in fast-tracked projects under the Covid-19 recovery bill, saying it was unrelated and should be subjected to the full process.
"We acknowledge the current low levels in Watercare's storage system, but don't support a short-term response that could cause long-term harm," board chair Rukumoana Schaafhausen said.
The matter would now go a Board of Inquiry led by a current or retired Environment Court judge, Parker said.
"The Inquiry will need to consider the viability of alternatives, including the treatment of storm and/ or waste water," he said.
"Water taken for Auckland from the Waikato already includes treated water from outfalls from storm water and treated waste water upstream of its take."
Auckland Mayor Phil Goff welcomed the announcement.
"We have argued strongly that the current system is broken and Auckland needs to be able to present its case without further delay.
"Auckland has been waiting over seven years and are still 106th in the queue to have our case heard."
The application is expected to still take up to nine months, through the inquiry.
Goff said the council would continue to work in good faith with the Waikato River Authority, the Waikato Regional Council and Waikato-Tainui to deal with the potential crisis Auckland may face over this summer and to find longer-term solutions.
"In the meantime, council and Watercare will work to explore every solution to increase Auckland supply and better conserve water to avoid Auckland facing a severe water shortage," he said.