The Whangārei Quarry Gardens could need up to $100,000 to repair the damage caused by the weekend's storm.
The gardens, on Russell Rd in Kensington, recorded about 220mm of rain between Friday night and Saturday morning after the storm wrecked havoc across Northland.
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The gardens experienced substantial damage with a number of slips causing debris to cover many of the walking tracks. Large holes were gouged into the tracks and the passages where water ran down from above the gardens were blown out after the intense rainfall.
"I'm absolutely gutted," gardens manager Guy Hessell said.
"On Saturday, I walked around with my eyes and mouth open wide with the extent of the damage and to see the sheer damage that can be caused by water."
Hessell, who had been in the role for just over 18 months, estimated he would need between $50,000-$100,000 to repair the damage to the gardens.
Volunteers were hard at work this week, shovelling debris from the tracks. The gardens had a core group of about 30 volunteers who helped with maintenance twice a week.
While he said there wasn't a severe need for more volunteers currently, Hessell would love to hear from anyone with access to a 3-12 tonne digger, as such resources would be a vital in restoring the gardens to their former glory.
He said 2020 had been a tough year for the gardens. As well as the environmental impact of the drought and the financial impact of Covid-19, the gardens were also robbed three times with a few hundred dollars being taken from their donations collection, which they no longer kept on site.
Hessell said the gardens relied heavily on donations and encouraged anyone who wanted to donate to head to their website and click on the "Contribute" tab.
While the gardens would be closed for the remainder of this week, Hessell hoped to open areas such as the camellia and upper bromeliad gardens by next week.
With a monumental job in front of him and his volunteers, he was confident the gardens could be repaired with a focus on limiting potential flood damage in the future.
"It's broken but not irreparable. It's not just a matter of reinstating it how it was, we need to future-proof it by putting in swale drains and possibly drains under the tracks to mitigate against damage in the future."