River health warnings
We monitor river sites regularly over the summer to check for bacteria (faecal contamination) and toxic algae.
Each river site is given a long-term grade prior to the summer monitoring season for suitability for swimming and recreation. The grade is based on the last five years of sampling. Sites that are not recommended for swimming because of their long-term grade are red on the Land Air Water Aotearoa (LAWA) website and signage should be in place at the site. Temporary Health warnings are issued when a site is graded as good to swim but there is now an increased risk of cyanobacteria or faecal contamination.
- Toxic algae (cyanobacteria) can occur in any waterway, at any time, so it is important that you know what it looks like. Find out more about toxic algae and how you can protect yourself and your animals.
- Faecal contamination poses a risk to health, it can cause gastrointestinal illnesses, respiratory diseases, and eye, ear, nose, throat and skin infections.
Temporary health warnings
Waihao River at Gum Tree Flat Road
Health New Zealand, National Public Health Service has issued a health warning for Waihao River at Gum Tree Flat Road (Don's Hole).
The warning follows finding moderate to high cover of potentially toxic harmful algae (benthic cyanobacteria) in the Waihao River at Gum Tree Flat Road (Don's Hole).
People should avoid the area and animals, particularly dogs, should not be allowed near the water until the health warning has been lifted.
There are also other access points along the Waihao River at Gum Tree Flat Road that may have benthic cyanobacteria present. People are advised to treat every low-flowing river cautiously, check for the presence of benthic cyanobacteria and avoid contact.