Coastal Water Quality Monitoring

Waikato Regional Council monitors a number of popular open coast beaches during the summer months to assess the suitability of the water for recreation such as swimming and surfing. We monitor these beaches weekly from November to March and the results are presented on the Council's website. This monitoring programme considers the suitability of the water at a number of recreational beaches by measuring ‘faecal indicator bacteria’ (enterococci in coastal waters). The number of bacteria present in the water indicate the likelihood of contracting a disease from many possible pathogens in the water such as bacteria or viruses. Results from the monitoring programme are compared to national guidelines to determine the suitability for recreation. The Waikato Regional Council also conducted a one-off survey of 18 coastal stream mouths in the Coromandel area during January and February 2015. Sites were selected based on their popularity and whether members of the community had previously raised concerns regarding water quality. The purpose of the survey was to investigate the water quality at these locations to provide an initial assessment of the suitability of these water types for the organisms that live there and the people that use them recreationally. Some of these water bodies were found to be particularly susceptible to contaminants (excess nutrients and faecal bacteria) that are washed from the surrounding land, particularly 24–48 hours after heavy rainfall. A more comprehensive follow-up study was carried out during January and February 2017 in four catchments (Opito Bay, Kuaotunu, Whitianga, and Tairua) to further identify potential causes of contamination. This study was designed to identify the source of faecal contamination within the catchment, linked to land use where possible, and whether it was from humans or animals. It also investigated how the concentration and source of contamination changed during dry and wet weather and during spring and neap tides. Estuary water quality monitoring is also undertaken every month in Raglan and Tairua Harbours.

Enterococci concentrations provided online for each site and date.

Swimming beaches on the eastern Coromandel Peninsula and West Coast of Waikato Region. Historical data may be available from other sites.

Recreational beach water quality November - March ongoing. Stream mouth water quality snapshot January-February 2015. Catchment study January-February 2017. Estuary monitorin October 2017-present

When collecting stream mouth data, water samples were collected during the outgoing tide to ensure sampling water that was coming down the stream. Laboratory results for each sample were compared to ANZECC guidelines and results relating to the suitability for recreation were compared to the New Zealand recreational water quality guidelines. The ANZECC guidelines are conservative, which means that exceedances do not imply that there are any adverse effects. Instead, further investigation may be necessary to determine the extent of the effects, if any.

Water quality can change dramatically over relatively short periods of time due in particular to rainfall events. These measurements are just a snapshot.

Data available online (see link below)

Used to provide water quality information online over the summer months.

Freely available.

Freely available.