Wellington Scoop
Network

Weekend rain washes poison from region’s rivers

News from GWRC
A rainy weekend has flushed toxic algae from the region’s rivers.

“We expect that all rivers in the greater Wellington region are now free from toxic algae. That’s certainly the case in Kapiti where the Otaki and Waikanae rivers flowed at around six times the flow required for flushing to occur,” says Dr Mark Heath, Senior Environmental Scientist, Marine and Freshwater, Greater Wellington.

“High flows were also seen in the Hutt River and Wairarapa rivers and we are very confident that they are free from toxic algae.”

The council’s water quality team will be out and about testing rives over the next couple of days, and the Is it safe to swim? website will quickly be updated with new – and almost certainly positive – information.

“The only drawback of the rain is that it can also flush potentially harmful contaminants into rivers and harbours, such as e.coli, which is why we urge people not to swim for at least two days after rain.”

Press Release – Greater Wellington Regional Council – February 22
Toxic algae warnings remain in place in Kapiti and Wairarapa.

Kapiti Coast – Levels of algae are still high in the Waikanae and 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.

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.

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.

“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.”

Content Sourced from scoop.co.nz
Original url