Water monitoring for recreational activities
The Otago Regional Council monitors the levels of bacteria in a number of rivers and coastal areas, particularly during the summer months when many people will be using rivers for contact recreation purposes.
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Recreational water quality monitoring
Water is not always safe for recreational activities, as it can sometimes become contaminated with human or animal effluent which contains large numbers of organisms capable of causing illness. The most common sources of bacterial contamination are human sewage, stormwater and rural run-off.
Samples are collected weekly from two of Otago's most popular coastal beaches and three freshwater swimming spots throughout the bathing season (1 December to 31 March) and tested for the presence of bacteria. In addition, six sites are monitored on a monthly basis. Coastal water is tested for enterococci, while fresh water is tested for Escherichia coli (E. coli).
Enterococci and E. coli are harmless bacteria that live in the gut of all warm blooded animals. Their presence in sea water or river water indicates that faecal matter (from sewage or animal effluent), and possibly disease-causing organisms (pathogens) may be present. It is impractical for councils to test for the pathogens directly because there are far too many kinds.
The results of the recreational water quality sampling are compared to national guidelines set by Ministry for the Environment and Ministry of Health.
Recreational water quality guidelines and standards
Water quality safety is assessed and reported according to the Ministry for the Environment and Ministry of Health 'Microbiological Water Quality Guidelines for Marine and Freshwater Recreational Areas' revised and issued in 2003.
The guidelines recommend a three-tier (traffic-light) management framework according to single sample results of E. coli (freshwaters) and enterococci (marine waters) bacterial counts. These categories are given below:
If the results from regional monitoring show levels elevated above the national guidelines, they are forwarded to the district and city councils, as well as Public Health South for follow up action.
Otago recreational water quality results 2009 - 2010
Depending on which site is monitored, between four and 17 samples will be collected during the bathing season from December 2009 to the end of March 2010.
Blue vertical bars show the bacterial count measured in the water on particular days. These are single sample counts.
Note the logarithmic scale of the bacterial indicator axis. This means that each mark on the vertical scale represents an increase of ten times the number, rather than just a doubling of the numbers.
Select a site from either the map or the list below to view the latest recreational water monitoring results.
Freshwater
Weekly Sampling:
Kakanui at Clifton Falls
Taieri at Outram
Manuherikia at Galloway
Taieri at Waipiata
Waikouaiti at Bucklands
Monthly Sampling:
Lake Waihola at jetty
Pomahaka at Glenken
Lake Hayes at surface
Marine and Coastal
Weekly
Pacific Ocean at Kaka Point
Otago Harbour at Macandrew Bay
Waikouaiti at Fishermans Wharf
Monthly Sampling:
Kakanui Estuary at Kakanui Bridge
Dunedin City beaches
For information on beaches that the Dunedin City Council monitor (St Clair, St Kilda, Middle Beach and Blackhead beach) visit the Swim Safe page of the Dunedin City Council website.
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