Health officials have renewed warnings about a toxic algae washing up on the edges of the Hutt River, after a dog died from coming into contact with it.
The Greater Wellington Regional Council and Regional Public Health Service says the level of cyanobacteria in the river is high, with thick clumps of algae mats washing up from Birchville downstream.
They say a one-year-old cocker spaniel died shortlyafter coming into contact with it near Heretaunga Park.
The health service says the toxins can cause vomiting, diarrhoea and skin irritation to humans.
It says the algae level will remain high until heavy rain.
It says there is a moderate risk from toxic algae mats in the Waikanae and Waipoua rivers.