Update on toxic algae throughout the region

Here is an update on the presence of toxic algae around the region. Please note there are changes from conditions that applied last week. In general, the Hutt valley has improved but warnings remain in place in Kāpiti and Wairarapa. Forecast rain is likely, and Greater Wellington will advise the community of any changes arising from it.

Kāpiti Coast - Levels of algae are still high in the Waikanae and especially the Otaki rivers. People are advised not to swim in the Otaki River, to monitor children playing by the riverside and to keep dogs on leads.

Hutt Valley - the level of algae in the Pakuratahi River has stayed under the guideline level and so the warning has been removed.  Although toxic algae levels are generally low in the Hutt and Pakuratahi Rivers keep an eye out for toxic algae and avoid contact if seen.

Wairarapa - Algae has reached high levels in the Ruamahanga River at Double Bridges and remains at high levels in the Waingawa River at South Road. People are advised not to swim in these areas, to monitor children playing by the riverside and to keep dogs on leads. Toxic algal levels are approaching guideline levels elsewhere in the Ruamahanga Catchment, so people should look out for the signs of toxic algae and avoid contact if seen. Levels of algae in the Waipoua River are currently low.

Wellington south coast streams - the Waipapa stream (which is near the Red Rocks car park) is assumed to have high levels of toxic algae, but wasn't tested this week.

"Given conditions quickly change, people should be remain vigilant around rivers and streams throughout the region. This is the prime season for toxic algae, so look out for algae covering rocks and for detached mats in the water and lining riverbanks. If in doubt, stay out of the water and keep a close eye on children and dogs," says Dr Mark Heath, Senior Environmental Scientist, Marine and Freshwater, Greater Wellington.

"The good news is relief looks like it's on its way. Rain is predicted for this weekend, and Greater Wellington's hydrology and climate scientists predict there will be enough to flush toxic algae from the Otaki and Waikanae rivers. But it is less clear whether there will be enough rain in the Wairarapa to fully flush the Waingawa and Ruamahanga rivers.

"The toxic algae warnings will be updated early next week if enough rain falls to get rid of the algae."

For more information on toxic algae, people should visit our webpage.