Health Warning - Unsafe Recreational Water Quality at Waihao River at Gum Tree Flat Road (Don’s Hole)
South Canterbury
10 March 2026
Health warning lifted at Waihao River at Gum Tree Flat Road (Don’s Hole)
Health New Zealand has lifted its health warning at Waihao River at Gum Tree Flat Road (Don’s Hole).
Latest water testing results show faecal bacteria levels at this site are now below guideline values and this health warning has been removed.
Dr Imogen Evans, Public Health Medicine Specialist for the National Public Health Service, says an existing health warning remains in place at Waihao River at Gum Tree Flat Road (Don’s Hole) for harmful algal bloom (benthic cyanobacteria). People should avoid the area and animals, particularly dogs, should not be allowed near the water until this health warning has been lifted. This warning was issued on 21 November 2025.
For further details
Canterbury region - LAWAexternal link
23 February 2026
Health New Zealand | Te Whatu Ora has issued a health warning after high levels of faecal bacteria were found in consecutive samples taken from Waihao River at Gum Tree Flat Road (Don’s Hole).
Dr Claire Salter, Medical Officer of Health for the National Public Health Service, says water quality at affected sites is not considered suitable for recreational uses including swimming because of the risk to health from the bacteria and other pathogens.
Water contaminated by human or animal faecal matter may contain a range of disease-causing micro-organisms such as viruses, bacteria and protozoa.
An existing health warning at Waihao River at Gum Tree Flat Road (Don’s Hole) remains in place for harmful algal bloom (benthic cyanobacteria). This warning was issued on 21 November 2025.
For further details and sites where water quality is affected visit:
- https://www.lawa.org.nz/explore-data/canterbury-region/river-quality/waihao-river/waihao-river-at-gum-tree-flat-road-dons-holeexternal link
- https://www.lawa.org.nz/explore-data/canterbury-regionexternal link
To contact your local National Public Health Service office visit:
To keep up to date with current health warnings visit: