Use Land, Air, Water Aotearoa's (LAWA) online guide (external link) to find safe swimming spots in Canterbury or keep up to date via our Facebook page (external link)

Swimming water quality monitoring is carried out at popular recreational river, lake and coastal bathing sites throughout Canterbury during summer, which allows us to assess baseline conditions, trends and public health risks.

Water samples are collected weekly from around 100 sites from mid-November to the beginning of March. Each bathing site is given an overall swimming water quality grade based on the testing of water samples collected by our staff and an assessment of the site’s susceptibility to faecal contamination.

Individual faecal indicator bacteria results are updated on our map when they are received from Hill Laboratory Services (external link) , generally within 24 to 48 hours of sampling.

Swimming water quality grades

testing swimming water quality

Our swimming water quality grades are based on guidelines established by the Ministry for the Environment and the Ministry of Health. They assess the risk of contracting a disease from faecal bacteria, such as campylobacter, giardia, salmonella, cryptosporidium or norovirus.

Sites graded very good, good and fair are considered suitable for contact recreation; however good and fair sites may not be suitable at times — for example, after heavy rainfall.

Sites graded poor and very poor are generally considered unsuitable for contact recreation; there is typically notification of this via signage at the site and/or through the media.

Even the cleanest spots can be unsuitable to swim in from time to time when they get contaminated. We recommend you avoid swimming during or shortly after rainfall as urban or agricultural run-off may result in high bacterial counts.

  • For a factsheet about how and why we test recreational water quality and how we grade different sites, click here.

Potentially toxic cyanobacteria

Our swimming water quality grades do not consider risks from the presence of potentially toxic cyanobacteria. Please note cyanobacteria warnings override the usual water quality grades for swimming.

  • For more information about potentially toxic cyanobacteria, click here.

Annual swimming water quality reporting

We provide information on the suitability of recreation grades at popular recreation sites in rivers and lakes across the region, as well as warnings for potentially toxic cyanobacteria, at the beginning of each summer.

  • For the latest annual report, click here.