Most of Auckland’s beaches have do not swim warnings or are classified at high risk due to sewage overflows.

Swimmers have been warned to stay out of the water at 21 places, including Mission Bay, Kohimarama, and St Heliers, Herne Bay, St Mary’s Bay, Beach Haven, Narrow Neck, Mairangi Bay, Milford, Howick, Point England, Taipari Strand, and Chapman Strand.

“Overflows are more common in wet weather, but they can happen in dry weather if pipes are blocked or damaged,” Safeswim’s website states. The region was hit by thunderstorms and heavy rain this week.

Other major beaches have been classified as “high risk” and swimming is not advised, including at Long Bay, Takapuna, Bayswater, Stanmore Bay, Orewa, Red Beach, Te Atatu Beach, Titirangi Beach, Blockhouse Bay, Litlle and Big Bucklands, and Cockle Bay.

Even Waiheke Island didn’t go untouched, with several beaches having a high risk alert, which indicated levels of Faecal Indicator Bacteria breached national guidelines for swimming.

Several areas also have a long-term high risk alert, including at Piha Lagoon and North Lagoon, Bethells Lagoon, Wood Bay, Green Bay, Lynfield Cove, and Coxs Bay.

Long-term alerts are issued when water quality samples taken at a location consistently fail to meet national guidelines.

Water quality at west coast beaches, including Piha and Muriwai, is rated as good.

For the latest information, see Safeswim’s website.