"It was the perfect time to reinvest in this sacred taonga," he said.
''For more than 400 years, this ancient source of water direct from Papatūānuku has been a place for healing and rejuvenation. Now, post Covid-19, we're back better than ever as a place where locals and visitors can come for their health and wellbeing.''
The upgrade may also be well timed to make the most of changes in post-Covid tourism. NZ Māori Tourism marketing manager Kiri Atkinson-Crean said travellers emerging from the pandemic would be drawn to deeper, more authentic experiences operating in balance with the land, its people and culture.
Accounts of Ngāwhā Springs date back to 1600, when Ngāpuhi ancestress Kareariki discovered the water's curative powers, particularly for giving relief to mothers after childbirth.
Robust said warring iwi and hapū would bathe together after battles to embrace the water's healing properties.
Notable Ngāpuhi warrior Hone Heke Pōkai used the pools following the Battle of Mawhekairangi, on the shores of Lake Ōmāpere, in 1845.
''Ngāwhā has always been special," Robust said.
''When visitors come to enjoy the beauty of the Bay of Islands, they're only 30km away from these healing thermal springs so steeped in history. It's a short hop over the hill but a big step back in time. Visitors and locals can bathe in the healing waters and let the ancient energy revitalise their senses while the minerals from deep in the earth permeate their body."
While the Ngāwhā Springs complex was closed the trust opened the former Ginns Ngāwhā Spa, temporarily dubbed Ginns The Temp, so Northlanders would still have a place to go for a hot soak.
Ginns was closed in 2015 after power company Top Energy, which bought the land for a power station expansion, found asbestos in some buildings. That has since been removed, and the Ginns complex was bought in 2019 by the Parahirahi Ngāwhā Waiariki Trust as part of the power plant consenting process.
The lead contractor in the Ngāwhā Springs revamp was Kaikohe firm Henwood Builders. Council-owned company Far North Holdings managed the project.
The complex was blessed on Friday to ready it for today's reopening.
■ Ngāwhā Springs will be open daily except Mondays. Winter opening hours (April 1 to November 31) will be 9am-2pm and 4-9pm; summer hours (December 1 to March 31) will be 7-11.30am and 5-9.30pm.