Water quality for swimming maps

Search the map above to find out if your local river or lake is suitable for swimming. See key below.

See the LAWA website for updates on swimming water quality at popular sites during the bathing season.

Swimming maps launched in early 2017 now include all rivers over stream order 4 and all lakes greater than 1.5 km in perimeter to ensure that they are consistent with the national target.

Swimming in our rivers and lakes is part of our way of life and we want future generations to enjoy this pastime too.

These interactive maps show which rivers and lakes are generally suitable for swimming, and where water quality for swimming could be improved. The maps are based on sampling of E. coli and toxic algae (by regional councils, NIWA and Cawthron), as well as information on catchment conditions such as climate, land use and geology.

The new target is 90 per cent of our rivers and lakes are swimmable by 2040. These maps sit alongside these targets, and will help inform community discussions about improving water quality for swimming in their region.

See Water quality for swimming categories (attribute states) in detail

Additional information shown on the maps

Warnings are also included at certain sites where other water quality factors may affect recreation. These warnings are based on regional council monitoring data.

For river sites these are:

  • low water clarity
  • a history of toxic algal blooms.

For lakes these are:

  • low water clarity
  • elevated E. coli levels.

What water bodies are shown on the maps?

  • Rivers stream order 4 and above with a permanent or intermittent flow. Note sections of rivers which are dammed and diverted, and do not require a minimum flow are not shown.
  • Lakes with perimeters over 1.5 km.

The underlying data to generate the water quality for swimming maps can be found on the MfE Data service as follows:

  • The Water Quality for Swimming Data for rivers
  • The Water Quality for Swimming Data for lakes


At a site level, there is some statistical uncertainty associated with each of the categories. On any one day a site could be in a higher or lower category for swimming.

Other factors can also affect how suitable a waterway is for swimming including flow, access, health and safety around infrastructure, heavy rain events, and other weather conditions. The maps don’t provide advice on these.

For these reasons, always check regional council websites and the Land, Air, Water Aotearoa website or infrastructure operators for the latest conditions and warnings at popular swimming spots before you swim.