Twenty years ago she attended a meeting among a group of friends and planned to overhaul the former quarry site.
She's since held the helm of the project, inspiring others to join her cause and create a garden wonderland.
Last year, Mrs Sparks was recognised for her efforts in the regional NZME Person of the Year Awards, winning the environment category for her efforts.
Over the past two decades, she spearheaded a campaign to turn 33ha of wasteland and rubbish into a flora and fauna paradise.
Part of this project involved persuading local government to hand over enough reins to allow Mrs Sparks and her band of volunteers to start work.
It's the volunteers who come every day. They deserve the credit, not me.
"I took them up to the top terraces, the councillors, and looked down into the depths of the quarry where there was this idea of an amphitheatre and I said 'can you imagine Kiri [Te Kanawa] singing in the quarry?' I think that was one of the things that stuck with them and it's nearly come to pass," she said.
Dame Kiri has yet to sing at the park but in 2010 fellow opera great Dame Malvina Major performed as part of a fundraiser for Te Puna School.
The park has become popular for performances, with the Outdoor Shakespeare in the Bay's production of Shakespeare's As You Like It featuring later this month.
"It's just wonderful, just fabulous," Mrs Sparks said.
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She said it was rewarding to see the park used so regularly by a range of people.
It was "astounding the number of volunteers who have come over the years", she said. "Some have come and some have gone, some have died, and we remember them. They have left their heritage in the quarry."
Kiwibank New Zealand Local Hero of the Year awards spokeswoman Nicky Barton said Mrs Sparks might not be able to help out on the ground much anymore, but its success was a testament to everything that she has done.