Nearly 100 time capsules hidden within Tauranga's old civic building in Willow Street for more than 30 years have been rediscovered during the building's demolition.

One of the time capsules that's been in Tauranga City Council's safe room has been reunited with the 89 time capsules that have been recently found, making a total of 90 time capsules originally planned to be left unopened for 100 years.

The former Tauranga City Council building has been home to the council's chamber, offices for administration staff, and the city library. In 2013 many council staff evacuated the building following the discovery of toxic black mould. The council's customer service centre and city library are now located in Devonport Road at the recently opened He Puna Manawa site.

Demolition of the Willow Street site will be followed by the development of a new city precinct, called Te Manawataki o Te Papa.

'Before the contractors LT McGuinness commenced in May, we made them aware that the time capsules were in the library and that we wished to recover them before the demolition began,” says Tauranga City Council senior programme manager Beau Fraser.

The time capsules packaged up at the Tauranga Heritage Collection. Photo: Supplied.

Beau says the broad location of the time capsules was understood to be somewhere in the vicinity of the lift shaft.

'The demolition project manager was purposely exploring the area around the lift shaft to locate the time capsules prior to the demolition commencing," says Beau.

'The capsules were found after removing a wall panel in the rear of the lift shaft room exposing a small storage space.”

Once located, the time capsules were all collected and transported to council's Heritage Collection facility where they were all receipted, packaged up and stored safely.

'I knew they were under the stairs because there was a plaque about them on the wall, but none of the current library staff or past managers knew exactly where – it took the demolition team to carefully dig them up,” says Tauranga City Council libraries manager Joanna Thomas.

'I had no idea what the 'time capsule” would look like."

Joanna says one of the libraries team was working at Willow Street in 1989.

'She recognised one long plastic tube in the safe room as one of the time capsules that was donated by the spinners and weavers club,” says Joanna.

'When the others were dug up we reunited the lost one with the other 89. I was surprised that there were 90 of them!”

Tauranga City Council's old building in Willow Street is being demolished. Photo: John Borren.

Families and community groups donated the time capsules through the Leo Club of Otumoetai in 1989 and 1990, with the intention that they would not be open for 100 years.

'From some of our Facebook posts about the demolition and the time capsules being found, we heard from a few ex-Leo members that they remember doing the project,” says Joanna.

'All 90 time capsules have been safely stored with our Heritage Collection team for now until a longer-term home for them is decided upon. The library would be interested to hear from any family or group who remembers their time capsule and what they think should happen to them.”

Tauranga City Council says on their Facebook page that as a decision on how the new civic precinct will be brought to life is still to be decided, they don't yet know exactly where the time capsules' future home will be.

'But rest assured, its location will honour the original intent. This is something we'll be keeping in our minds as we work through the next design phase for the project. We'll be sure to keep the community updated,” writes a council spokesperson in the Facebook post.

As to the contents of the capsules, this is unknown, although one of them dated August 1990, has written on it: 'To our future generations with love”.