An environmental group has labelled the dumping of an unknown substance in a West Auckland creek "disgusting".
Residents woke up this morning to discover a tributary of Whau River had turned white, and it's feared the pollution could impact endangered species.
Whau River Catchment Trust environmental coordinator Amber Simmonds says discovering strange substances in the local creek is demoralising.
Her group has been working to restore the area for nearly 20 years.
"It's really the community that would be quite saddened to see that this is happening, because they're the ones that put the hard work and the thousands and thousands of hours into restoring the riverside."
There are also concerns about the impact on wildlife.
"We've got kingfisher, and we do have other birds feeding here - a lot of seabirds, so they're going to be eating food that's possibly contaminated now," says Ms Simmonds.
It's feared the substance could seep down to the mouth of the river, where there's a marine reserve inhabited by endangered species such as banded rail and fernbird.
Auckland Council says it's taken samples, but it hasn't yet confirmed what the substance is.
It's believed the source of the contaminant is from the stormwater drain. Earlier, it was overflowing into the creek, but it's now been stopped by council workers who've been pumping it out.
The council says it's tracked down the source, and is considering enforcement action if appropriate.
Newshub.
