A simple observation while on holiday in Europe spurted a grand ambition for 9-year-old Lilah O'Leary - to double the number of drinking-water fountains in Auckland.
Takapuna resident Lilah noticed while gazing at a large bank of public water fountains in Warsaw - slurped at by human and dog alike - that similar scenes were remarkably absent from her homeland.
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In fact, the budding Year 4 environmentalist rarely recalled seeing a single water fountain at most parks and playgrounds she visited in Auckland.
"Before this, I had never really thought about water that much but I couldn't help but notice there was a very noticeable increase in water fountains overseas.
"I also noticed that people were filling up big plastic bottles that otherwise would be single use, and I thought that was a really cool idea, because so much plastic goes into the ocean.
"So when we came back to New Zealand we started researching, and we found out that Auckland is very behind on the amount of water fountains."
The Auckland Council region has only 370 public water fountains in total - equating to one for every 4480 residents.
In contrast, Brisbane has a water fountain for every 1600 residents, and Melbourne has one water fountain per 1125 residents.
This discrepancy motivated Lilah, with help from mum Kate, to conceive the Public Water Project.
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Their fundraising aim is three-pronged.
Firstly, have a multitude of companies sign up to sponsor $10,000 to install a new public drinking-water fountain - which will be gifted to the 84 per cent of Auckland's parks without a single one.
Secondly, a competition will be run with local schools to design artwork to be printed on the fountain to raise community awareness and pride in the fountain installation.
Thirdly, a series of environmentally appropriate collectables for children when they use a fountain is hoped to incentivise children to seek out the fountains and drink water - avoiding more sugary drinks.
Ultimately, the public water project aims to double the 370 public water fountains in the Auckland region by the end of 2020.
The O'Leary family say they already have about 20 fountains locked in via developers.
"The interesting thing is they're doing all these big affordable-housing developments, and there's no requirement to put any fountains in," Kate O'Leary says.
"One of the developers we're talking to was like, 'oh, this is a brilliant idea'.
"A 400-house development in South Auckland and they're building a playground and they're not even thinking about water fountains."
Auckland is also in desperate need of an upgrade to its water fountains for another reason. In May, the Herald uncovered four in 10 drinking fountains in the Super City are dirty and mouldy.
Auckland Council's service development manager, Bryce Pomfrett, said the council supports the O'Learys' project in principle and is happy to work with them once planning and funding is more secured.
"It's great to hear about Lilah and Kate's project - we couldn't agree more with the need to reduce the amount of plastic and increasing opportunities for people to access tap water in public places," Pomfrett said.
"Once they are ready, we are happy to work with them on the best way to approach the right local boards, who are responsible for this infrastructure on public parks."
Wai Auckland - a new collaboration between the Healthy Auckland Together coalition and several council-controlled organisations (CCOs) which aims to facilitate tap water as an easier choice over sugary drinks - also supports the Public Water Project.
"It depends where the drinking fountain is and who owns the land, because they're the ones responsible for the water going into it and paying for that upkeep and maintenance. So there's just a few things we need to figure out," Wai project manager Amanda Brien says.
"But there have been previous examples where members of the public donated resources to council. We support the Public Water Project in principle."
Unsurprisingly, Kate O'Leary says another precocious child environmentalist is a common topic of conversation at home: "We hear a lot about Greta in our house."
Lilah too can't deny the parallels between Thunberg and her own youthful ambitions.
"I think what she's doing is great - my sister's a huge fan of her," Lilah says.
"A lot of our inspiration is Greta. I think it's really cool how one person can make such a big difference."