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Factsheet: What do the swim icons mean?

LAWA provides the most comprehensive recreational water quality information in New Zealand for you to use as a guide in deciding when and where to swim.

  • Check that water is clean and clear, and avoid swimming for 2 - 3 days after heavy or prolonged rainfall, even at sites that usually have good water quality.
  • Know what potentially toxic algae (cyanobacteria) looks like in rivers and lakes and do not swim in areas where it is present.  

 

Latest result

The most recent result from weekly water quality monitoring or the current predicted risk. 

Suitable for swimming.  This site met the water quality guidelines for faecal indicator bacteria and/or potentially toxic algae when sampled, OR the predicted result is that this site has a low health risk and likely to meet water quality guidelines for swimming.

Caution advised.  Water quality usually suitable for swimming, but young children, elderly or those with compromised health may be at increased risk.

For lakes and rivers that are routinely monitored for potentially toxic algae – this site exceeded the surveillance criteria when recently tested.  Avoid contact where potentially toxic algae is present.

Unsuitable for swimming.  This site did not meet the water quality standards for faecal indicator bacteria when sampled, OR the predicted result is that this site has a high health risk and is unlikely to meet water quality guidelines for swimming.

For lakes and rivers that are routinely monitored for potentially toxic algae - this site exceeded the action level criteria when recently tested.  Avoid contact with the water and potentially toxic algae on the edge of the water.

Not available. The predicted data is temporarily unavailable, or the weekly monitoring result is more than 2 weeks old (or more than 3 weeks old for toxic algae).

 

Councils test the water quality of popular swim sites each week over the recreational bathing season.  These results provide a snapshot of what the water quality was like at the time of sampling.  Auckland Council and Greater Wellington Regional Council use modelled data to predict the water quality result.  This provides real-time information on the current water quality at a site.  Results are shown against national water quality guidelines - see the Recreational water quality monitoring in New Zealand factsheet for more. 

 

Special status

This category is used for sites that are no longer regularly monitored and have enough historical data to assign a long-term result, or for sites with temporary water quality issues.

Suitable for swimming. 

This represents some of the best recreational water quality sites in New Zealand.  A site assigned this status has been shown over a number of years and conditions to have water quality that is considered excellent for swimming.

These sites have met the following criteria:

  • no known risk factors (e.g. algal blooms or discharges),
  • no exceedances of the national guidelines within the last 3 years, and
95th percentile result is less than 50 Enterococci / 100ml or less than 160 E. coli /100ml for data measured over the last 6 years with a minimum of 60 data points. 

Caution advised. 

Current conditions at this site may pose an elevated risk to swimmers. 

This site may be experiencing temporary water quality issues or is known to be susceptible to intermittent toxic algae blooms from time to time. 

See the site page for more information on why a site has been assigned this special status.

Unsuitable for swimming.

This site has a history of poor water quality or has been temporarily assigned this status due to a recent event causing water quality issues (e.g. a pollution event, a potentially toxic algal bloom, etc).  

See the site page for more information on why a site has been assigned this special status.

 

Long-term grade

A precautionary risk guide to water quality at a site over the recreational bathing season.  The long-term grade is calculated from the weekly monitoring results for faecal indicator bacteria collected over the previous five years.

Excellent.  This represents some of the best recreational water quality sites.  A site assigned this status has been shown over a number of years and conditions to have water quality that is considered excellent for swimming.

 

Good. This represents sites that usually meet water quality guidelines, and water quality is considered generally suitable for swimming.

Fair. This represents sites in New Zealand that sometimes exceed the water quality guidelines, and water quality is often suitable for swimming.  To better understand the risk at this site, we recommend looking at the monitoring history.  

Poor.  This represents sites that occasionally or frequently exceed water quality guidelines.  To better understand the risk at this site, we recommend looking at the monitoring history or contacting the council for more information. 

Not available.  There are not enough monitoring data to calculate a long-term grade for this site.

Long-term grades are determined using national guidelines - see the Recreational water quality monitoring in New Zealand factsheet for more information.

 

Reminder - water quality can change 

When deciding where and when to swim, we advise that you check to see that the water is clean and clear, and to avoid swimming for 2 - 3 days after significant rain, even at sites which usually have good water quality.  At some sites, LAWA can access nearby real-time rainfall or river flow data.  At these sites, the raindrop icon will appear when there has been enough rainfall to potentially affect the water quality.

Conditions may have changed. 

There has been significant rain since the water quality was last tested.  This may have affected the water quality at this site.

    

More information

  • Faecal indicator bacteria (Enterococci and E. coli) factsheet
  • Potentially toxic algae factsheet
  • Recreational water quality monitoring in New Zealand factsheet