Fresh warnings concerning several Wellington and Canterbury waterways

Red alert level warnings have been issued for several Wairarapa and Hutt rivers, including Ruamahanga River, the length of the Waipoua River, the Te Awa Kairangi Hutt River and upstream of the Silverstream Bridge.

And moderate to high cover of potentially toxic algae have been detected in the Waikirikiri Selwyn River at Glentunnel and Whitecliffs.

Health officials say exposure to skin can cause rashes, nausea, and numbness around the mouth and fingertips.

They're urging people to keep their dogs away from the waterways, until the warnings have been lifted.