16 Auckland beaches are officially too risky to swim at.

Auckland Council's new water quality forecast website, Safeswim, lists 16 beaches where swimming is not recommended because of high enterococci levels - a bacteria produced in the guts of animals.

They are Cox's Bay, Weymouth Beach, Wairau Outlet, North Piha Lagoon, Laingholm Beach, Taumana East, Clarks Beach, Fosters Bay, Meola Reef, Little Oneroa Lagoon, Piha Lagoon, Te Henga Lagoons, Wood Bay, Green Bay, Titirangi Beach and Armour Bay.

The faecal contamination could be from any animal, including humans.