New Zealand's beaches, coastlines and rivers are shining jewels in the country's crown, but which ones need a bit more polishing?

For most, a Kiwi summer typically means inordinate amounts of time relaxing on a beach or near water, but a number of popular spots fail water quality measures used by councils including Auckland, Greater Wellington and Environment Canterbury.

Areas which don't meet the standards are normally signposted with warnings it is unsafe to swim, and undergo increased testing.

Safeswim has assessed all of the more than 180 beaches and freshwater sites in Auckland, and has selected 69 for weekly monitoring over the 2014-15 season.

The Greater Wellington Regional Council, along with other local councils, monitor 61 beaches and 24 river sites across the region where people frequently swim. Wellington sites are monitored weekly from mid-November to the end of March.

Water temperature and seaweed or algae cover are also measured, while river sites are tested for clarity.

Water from test sites is compared with national guidelines set by the Ministry for the Environment and the Ministry of Health.

The guideline "trigger level" for beaches which would require more monitoring is more than 140cfu (colony forming units) of enterococci bacteria per 100ml of water, while the threshold for rivers is at 26 cfu/100ml of E.coli.

"Surveillance mode", the lowest of three levels, means there's a risk of illness from swimming, but is acceptable eight in every 1000 swimmers in freshwater and 19 in every 1000 in coastal water.

If water quality reaches the "alert" category, the risk of someone getting sick is increased but still in the acceptable range and increased monitoring is carried out.

See the rest here:

Which NZ waters shouldn't you swim in?