Upper Hutt residents are furious that the flushing of a local dam has left dozens of fish dead in the creek below, and washed up on people's property.
The Greater Wellington Regional Council's flush of the lake at the top of the Birchville dam left heavy sediment downstream, alarming residents who came across dead trout, smothered in mud.
Upper Hutt resident Euan Green was one of the first to take a look.
"Me and my father went up there, I grabbed my waders and dropped in at the first waterfall and the sediment's like 200-300 millimetres thick and there's dead trout.
"So I walked up with a fishing net and kept finding no sign of life, no insects, no eels, no freshwater crays and just kept pulling out dead fish every 100-odd metres."
He said that part of the river was usually teeming with life.
"Quite regularly we'd see a dozen trout sitting there quite happily in the stream... feeding on cicadas in the summer."
Upper Hutt city councillor and Regional Council candidate Ros Connelly also went for a walk up to the creek, which feeds the Hutt River, and was disturbed by what she saw.
"The whole length of the stream from the dam down to the Hutt is absolutely coated in sticky, muddy sediment that's coated the entire stream bottom.
"It's killed fish species but it's also killed all of the invertebrates and insect life that lives in the river."
The debris and dead fish then paid a visit to downstream properties.
Georgie Payne whose property backs onto the creek was one of them.
"We had dead fish - a total of seven eel and trout as well as some of the creepy crawlie crab like things - on the bottom of our property and still have debris sitting in the stream on our side of the water.
"The sediment at the bottom of the stream in the waterfall area is thick with debris, the stream in places where I can see, is absolutely covered with at least a foot of sediment still."
Mrs Payne said it was "very smelly" and the Regional Council should have notified residents that they were flushing the dam, for health and safety reasons.
She said there were signs put up near the walkways by the creek, but property-owners near the creek weren't told and a Facebook post on 23 September, the day the work was carried out, was not good enough.
Many residents soon took to the council's Facebook page, demanding answers.
The council replied saying a ranger had checked out the creek multiple times since the flush, but never saw any dead fish.
In a statement, the council said while a number of observations had been made, the facts had yet to be established and it could not comment until the creek had been inspected.
It would visit the site, with Fish and Game, tomorrow.