KEY POINTS:
Nearly a third of 500 swimming spots surveyed around the country are not safe, it has been revealed.
A Consumer New Zealand water quality survey has found 29 per cent of beaches, lakes and rivers have bacteria levels so high that the Ministry for the Environment recommends staying out of the water.
Consumer NZ chief Sue Chetwin said a lack of helpful information from councils means swimmers at many other beaches may be at risk of campylobacter and ear, eye and skin infections.
Fine weather sent swimmers to the beaches yesterday, with temperatures above 20 degrees in much of the North Island. Weather forecasters expect good beach weather to last through the Christmas and New Year holidays.
See the list of best and worst beaches
However, the Consumer survey shows those cooling off at some popular swimming spots risked getting sick.
During summer, councils test enterococci and E.coli levels at popular swimming sites weekly.
About half compile the results over several years to rank beaches in five grades, from very good to very poor. The likelihood of contamination from sources such as stormwater, sewage or agricultural run-off is also taken into account. Good and very good beaches are safe for swimming most or all of the time, while poor and very poor beaches are not safe for swimming.
Consumer NZ compiled results from 10 regional councils and found only 17 per cent of 501 graded swimming spots ranked "very good". Twenty-nine per cent were "good", a quarter "fair", and the rest - 29 per cent - ranked poor or very poor.
Ocean Beach stream in Northland and Kawakawa Bay, south of Auckland, were among those ranked very poor - the level where the ministry says councils should have up permanent "no swimming" signs.
Beaches ranked poor included spots at Paihia, Mangawhai, Gisborne's Waikanae Beach and Rere Rock Slide, which is featured on AA's "101 Must-Do" list.
Ms Chetwin said it was "completely inadequate" that about half of councils used the five-grade ranking system. In Auckland, only Manukau ranks its beaches in five grades, while the others simply tell swimmers whether the water was safe at the latest test.
"Grades give a better picture of what the recreational water quality is like," said Ms Chetwin.
"The grades are done over time - the E.coli count just tells you at a moment in time.
"Some [councils] are saying they need five years of results but I would have thought they could just use the results they have now."
Auckland City beaches were among those that did not provide information for the survey, which comes as the Auckland City Council is preparing to cut $86 million from stormwater improvements over the next decade.
The cuts will result in sewage overflows at popular Eastern Bays beaches - St Heliers, Kohimarama and Mission Bay - occurring for years longer than planned.
However, utility and environmental manager Mike McQuillan said the beach grading system was subjective and less scientific than using the latest test results. He said Auckland councils had been talking to Government ministries about different ways of grading beaches but no one had come up with a system appropriate for Auckland. One of the problems was that the tests took days to be processed in the lab.
Mr McQuillan said Auckland's water quality was generally very good.
"There are very, very few - maybe 5 per cent - of failures ... and when we test it again it's generally okay," he said.
"The message we have is, if it's been raining think a little bit about where you swim."
For councils who do not use grades, safety thresholds are based on an "acceptable level of risk" of getting sick, Consumer NZ said. For coastal sites, the acceptable risk is 19 in every 1000 bathers getting sick; for freshwater sites, it's eight in every 1000 bathers.
Very Good
Maraetai beach
Russell beach (mid north and mid south)
Mt Maunganui beach (Ocean beach surf club)
Papamoa beach (surf club)
Lake Rotoiti
Very Poor
Mangere Bridge
Kawakawa Bay
Whangarei Falls
Paihia (Te Haumi)
Mangawhai (Norfolk Pine)
- Additional reporting: Bernard Orsman
