Swimming water quality

Information on the general suitability for swimming at popular sites in Canterbury during summer, based on risk of faecal contamination and water testing for faecal indicator bacteria. Swimming water quality grades do not cover toxic algal blooms - current warnings on toxic algae are provided at the links below.

Is your favourite swimming spot healthy?

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Swimming water quality

Recreational water quality monitoring is carried out at a number of popular river, lake and coastal bathing sites throughout the Canterbury region; to assess baseline conditions, trends and public health risks from contact recreation. Each site is graded according to its general suitability for recreation. A suitability for recreation grade is based on the risk of faecal contamination to a site, supported by water testing for faecal indicator bacteria 1,2.

1.Faecal indicator bacteria: Escherichia coli (E. coli) is used as the faecal indicator for fresh waters (rivers and lakes). Enterococci is used as the faecal indicator for marine waters.

2 The suitability for recreation grade follows the Microbiological Water Quality Guidelines for Marine and Freshwater Recreational Areas (2003) produced by the Ministry for the Environment and Ministry of Health

Note: the snapshot is merely of part of the map of swimming water spots in Canterbury. View the full map.

This map will give you an indication whether a swimming spot is generally suitable for swimming, based on risk of faecal contamination and water testing for faecal indicator bacteria. However, even the cleanest spots can be unsuitable to swim in from time to time when they get contaminated. We recommend that you avoid swimming during or shortly after rainfall as urban or agricultural run-off may affect bathing water quality at these times. If recent faecal contamination at the swimming spot is detected, the district council will erect signs, warning of the health risk.

Considered satisfactory for swimming at all times. Therefore these sites may not require monitoring on a regular basis.

Good

Satisfactory for swimming most of the time. Exceptions may include following rainfall.

Fair

Generally satisfactory for swimming, though there are many potential sources of faecal material.Poor

Generally not suitable for swimming, as indicated by historical results.

Very poor

Avoid swimming, as there are direct discharges of faecal material.

The Suitability for Recreation Grade describes the general condition of a site at any given time. The risk of becoming sick from swimming increases from sites graded ‘very good’ to ‘very poor’. Sites graded ‘very good’, ‘good’ and ‘fair’ are considered suitable for contact recreation, although ‘good’ and ‘fair’ sites may at times not be suitable (for example after heavy rainfall resulting in high bacterial counts). Sites graded ‘poor’ and ‘very poor’ are generally considered unsuitable for contact recreation, and there is typically public notification of this, via permanent signage at the site and/or through the media.

The faecal indicator bacteria results are updated weekly on the swimming water quality map, with the result typically available within 36 - 60 hours of the sample being collected. There is no current analytical method that will provide “real-time” faecal indicator bacteria results. At present the sample needs to be incubated for 24 hours to culture the faecal indicator bacteria to provide a result. Once the results are sent through to Environment Canterbury they have to be downloaded to a database with the results then uploaded to the website at midnight. Faecal indicator bacteria vary greatly in space and time, therefore a one off sample is not indicative of the sites suitability for recreation, and with a timeframe of 1-2 days before results are reported, a site can change rapidly. It is recommended that the suitability for recreation grade is used to determine whether a site is suitable for swimming.

For more information of how recreational water quality is monitored and grades are calculated visit this page.

Summary report of 2013–14 monitoring season

This summary report provides information on the suitability for recreation grades for popular swimming sites across the region, and warnings for potentially toxic cyanobacteria (‘toxic algae’) in rivers and lakes that occurred over the 2013-14 summer season. Read the report (pdf 8.36 MB)