Faecal contamination and toxic algae (cyanobacteria) can occur at popular recreational swim sites throughout Waitaha Canterbury.

The National Public Health Service issue health warnings for our region based on the information we provide through our monitoring programme. 

We monitor 99 sites across Waitaha Canterbury for faecal contamination and toxic algae (cyanobacteria). Regular monitoring helps us to assess conditions, trends and public health risks.  

Long-term grades

Every year, swim sites are given a long-term grade prior to the summer monitoring season for suitability for swimming and recreation. The grades are based on guidelines established by the Ministry for the Environment and the Ministry of Health and consider the last five years of sampling and sanitary surveys. Sites that are not recommended for swimming or other water-based activities such as kayaking, surfing or paddleboarding are red on the Land Air Water Aotearoa (LAWA) website(external link) and the local territorial authority will erect signage at the site.

Temporary health warnings

Temporary health warnings are for sites that were graded as suitable for swimming or other water-based activities at the start of the monitoring season, but high levels of faecal indicator bacteria or toxic algae (cyanobacteria) have recently been found. 

They are issued by National Public Health Service who release the information to the community and the relevant territorial authority will erect signage at the site. Temporary health warnings can be found on our website (below) and on the LAWA website. 

Sites may also have advisory notes, such as information on shellfish, toxic algae and to avoid swimming after rainfall.  

Mahinga kai

Water containing micro-organisms, chemicals, phytoplankton or cyanobacteria can pose a risk to health through recreational contact, drinking and gathering mahinga kai. Find out more about mahinga kai and health warnings(external link).

Avoid swimming after heavy rain

Swim sites can be affected by rainfall, especially those with a long-term grade of fair or poor. It’s important to avoid swimming and all other water-based activities for 48 hours after rain because there is an increased risk of faecal indicator bacteria in the water. Even if the water looks clear, it doesn’t always mean it is good to get in. 

River, marine and lake health warnings

River health warnings

View the latest river health warnings.