Bright green Wellington stream result of attempt to track leak

Wednesday, 3 February 2021

The Kaiwharawhara stream running bright green on Monday evening, a result of safe vegetable dye used by the council to trace leaks.

Locals voiced concern on social media after a Wellington stream was dyed bright green on Monday evening.

Photos of Kaiwharawhara stream at Trelissick Park, Ngaio, showing the water turned bright green, were posted online, sparking concern about algae and engine coolant.

In fact, the colour was a result of Wellington Water tracing a leak, but some members of the online community were concerned the stream was polluted with engine coolant or another poisonous substance.

The Greater Wellington Regional Council environmental pollution team confirmed the green tinge was caused by non-toxic vegetable dye, used by Wellington Water contractors investigating historic pipe issues upstream.

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Johnsonville resident Ginette Spence discovered the bright green stream while out walking her dog, Luca.

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Council spokesperson Stephen Heath said the dye helped trace the source of any leaks in water pipes, and was commonly used for that purpose.

There were no negative health effects on the water or its inhabitants but, while dogs might be okay, people should avoid swimming in the Kaiwharawhara stream, dyed or not, Heath said, due to poor water quality trends.

Johnsonville resident Ginette Spence, who posted the pictures on Facebook, discovered the stream’s unusual colour while walking her dog, Luca, who was unimpressed at being kept away from the water.

Commenters on Spence’s post suggested the green tinge was caused by engine coolant or antifreeze, which are commonly coloured bright green to prevent accidental poisoning.

Heath said, “In terms of the dye, people shouldn’t be concerned. However, if they do have concerns about discoloured water they should call our 24-hour environmental hotline on 0800 496 734, and we’ll look into it”.

Wellington Water spokesperson Alex van Paassen said this particular dye test came after a service request from a member of the public in the area of Warwick St, Wilton.

A leak in one of the water pipes was discovered, and the next step would be to send in a camera to plan repairs. The dyed water had then made its way from the water pipes into the stream.