Toxic algae in Hutt River

Toxic algae has again been found in parts of the Hutt River.

Monitoring of the Hutt River at Silverstream shows the amount of toxic algae mats growing on the river bed has returned to moderate levels. 

If ingested the algae can kill livestock and dogs, and contact can cause vomiting, diarrhoea and skin irritations in humans. Authorities are warning dog owners to keep their dogs on the lead and for people to take care.

“Rainfall earlier in the month had washed toxic algae out of the Hutt River following a warning over the Christmas/new year period but the warm temperatures and dry weather since then have seen it return to moderate levels” says Wellington Regional Council Senior Environmental Scientist Summer Greenfield.  

“The warning doesn’t mean that people shouldn’t use the river but we advise people to find out what toxic algae looks like atwww.gw.govt.nz/toxic-algae-faqs and to avoid it if they come across it while swimming.  We also recommend people keep their dogs on a lead.”

Upper Hutt City Council has posted toxic algae information signs at key access points to this part of the river.

Monitoring of Wellington waterways and coastal areas is carried out by Greater Wellington Regional Council and local authorities on a weekly basis over the summer months. Results of the monitoring and latest warnings are posted at www.gw.govt.nz/summer-check.

Other information about toxic algae, including a guide of what to look for and what to do if you are worried about possible contact with toxic algae can be found at www.gw.govt.nz/toxic-algae-faqs . 

Media contact: 021 914 266 or comms@gw.govt.nz


Summer Greenfield

Senior Environmental Scientist

Environmental Management Group

Greater Wellington Regional Council

04 830 4069, summer.greenfield@gw.govt.nz


Medical Officer of Health

Regional Public Health

04 570 9002