Monday’s rain in Auckland has again washed faecal matter into the Waitematā Harbour, making many Auckland beaches unfit for swimming. 

That’s according to the council-led Safeswim website, which provides real-time water quality information for the city’s beaches. 

Ten beaches around the harbour have been assigned a black flag today including Ōkahu Bay, St Mary’s Bay, Cox’s Bay, Howick Beach and Herne Bay. Swimming at these spots comes at a “high risk of illness” due to wastewater overflow, the website says. 

And at least 17 are red-flagged, including popular beaches like Takapuna, Milford, Cheltenham, Mission Bay and St Heliers. 

These beaches have “water quality predicted to exceed guidelines”, also bringing a high risk of illness, according to Safeswim. 

The Safeswim website shows swimming at many Auckland beaches brings a high risk of illness today thanks to heavy rain washing sewage into the sea. 

It’s still okay to swim at several beaches in East Auckland including Maraetai, Eastern Beach, Bucklands Beach and Cockle Bay. However, Mellons Bay and Kawakawa Bay are red-flagged and Howick Beach has a black flag. 

Other low-risk options include beaches around Massey and Te Atatū, as well as the popular Pt Chevalier. 

Safeswim predicts water quality will improve at some beaches during the day, with Mission Bay likely to be safe by lunchtime and Takapuna and Howick both low risk by this evening. 

Most beaches on the Manukau Harbour also have good water quality today, although swimmers are advised to take care because the harbour has strong, dangerous currents. 

Pt Chevalier beach is among the low-risk options for swimmers. Photo / Alex Burton 

There are more swimming options available than in late December, when a swath of beaches across the Waitematā had red and black flags in the sweltering hot week after Christmas. 

The flags have become a common sight in Auckland following heavy rain, which causes sewage to overflow from manholes, pump stations and gully traps and make its way to the sea. 

Damaged, ageing pipes also contribute to the water pollution. Judges Bay in central Auckland has been black-flagged for months after a sewer line in Parnell collapsed in September, opening a massive sinkhole and pouring millions of litres of sewage into the harbour. 

Watercare in October built a bypass around the blocked sewer main, which had a massive sinkhole open in Parnell. Photo / Watercare 

The damaged pipe should be repaired by March, but more work will be needed to strengthen the line. 

Long-term the completion of the Central Interceptor — a huge new wastewater tunnel — should make most sewage overflows a thing of the past. The project is expected to be finished in 2026.