Many of Auckland's "high-risk" swimming spots have been cleared for the public after water quality measuring systems indicated high levels of faecal contamination.
Auckland Council issued red warnings to over 50 beaches on Monday after testing found there was a greater than 2 percent chance of getting sick from swimming at these spots.
As of Tuesday, 12 places are deemed long-term high-risk areas where the rule is "do not swim". Three additional beaches have short-term risk notices.
Monday's warnings came after wastewater systems were overwhelmed by heavy rain during the weekend.
Long-term high-risk areas
West:
- North Piha Lagoon
- Piha South Lagoon
- Bethells Lagoon
- Fosters Bay
- Titirangi Beach
- Wood Bay
- Green Bay
North:
- Wairau Outlet
Central:
- Oakley Creek
- Meola Reef
- Cox's Bay
Waiheke Island:
- Little Oneroa Lagoon
Short-term high-risk areas
West:
- Huia Beach
North:
- Little Manly
- Okoromai Bay
When contaminated by human or animal faeces, the water can contain disease-causing bacteria, viruses, and protozoa, which can cause illnesses and infections.
Safeswim's water quality forecasts take rainfall, wind, tide, sunlight, and beach-type into account.
There are no beaches currently at a black alert or "very high risk" of illness from swimming, which occurs when water is directly contaminated by human faeces.
According to Safeswim's website, their water forecasts are built using high-frequency targeted sampling on top of historical monitoring results and are underpinned by the best available meteorological data.
Safeswim's forecasts are automatically overridden if sensors detect unpredicted events - like a wastewater overflow in dry weather - that are likely to cause a public health risk.