Why is my tap water brown, and is it safe to drink?

Aug 07, 2023

When Auckland woman Lorraine Vawdrey ran her grandchildren a bath at her daughter's Māngere Bridge home, she was shocked to see the bath fill with yellowish, brownish water.

According to her daughter, this was nothing new. The water at her home had been running tea brown following the big weather event that hit the region back in February. Since then, she had had only a few days of clear.

She had contacted Auckland's water management company, Watercare, which had sent someone out to flush the pipes beyond her property. That worked initially, but the brown water came back a few days later.

"My daughter thought it may be residual stuff in the hot water tank, so she ran three baths to empty the cistern, it's been two weeks again and the water is still brown."

READ MORE: * Yellow tap water plagues south Auckland residents for three months * Napier's murky water nightmare - when will it end? * Napier residents reported black water months before chlorination of network * Discoloured tap water stains clothing, raises health concerns on Auckland's North Shore * Warning for murky water over weekend due to Watercare maintenance * Coastal family unhappy about brown-tinged tap water

Stuff has heard of brown or discoloured water in several streets in the Māngere Bridge area, including Tapuwae Way and Coronation Road.

Watercare spokesperson Mel Verran said in an email, that the last reported fault from Tapuwae Way was from December last year, and at the time the local pipes were flushed, and the issue was resolved.

She said they had had one report of discoloured water from Coronation Rd, Māngere Bridge in the past six months.

"On May 1, our crew flushed the watermain on Coronation Rd after a report of discoloured water. The customer then confirmed their water was running clear again."

They re-confirmed that the water they supply is safe to drink.

She said anyone who has had discoloured water should report the fault on Watercare's website or by calling them on 09 442 2222.

"Our standard advice to customers who experience discoloured water is to turn on their outside tap for about 10 to 15 minutes to clear their private pipes. If the problem continues, we ask them to give us a call so we can investigate.

"All the water we supply in Auckland – including Māngere – is safe to drink. There is no need to boil or filter the water".

Have you been affected? Email [email protected]

A Wellington plumber, who did not wish to be named, said discoloured water is a common issue that is often caused by one of two issues: the water company turning off the water, creating a build up of sediment, which flushes out when the water is turned back on. Turning the water on again may make taps sputter and run brown briefly. It could also be due to older galvanised steel pipes in the home that may need removing.

If the mains pipes are cast iron, the yellow-brown colour could be iron in the water, which isn't ideal, but is not dangerous.

Vawdrey did not think the issue could be old pipes in the daughter's home, as the family had new plumbling put in when they renovated the bathroom about four years ago. When they contacted a plumber for advice recently, he advised them to collect a bottle of the water for possible testing.

"I'm trying to arrange an undersink filtration unit for her drinking water, because it's not cool to keep having to use plastic water bottles," says Vawdrey. "She doesn't even want her children sitting in it, let alone drinking it.

"It seems that people along Coronation are the ones that are having the biggest problem in the community. When I put a post up about it on the community Facebook page, there was a lot of people saying the same thing."

It's not the first time Māngere Bridge residents have complained of discoloured water.

In 2019, yellow water with a "clay-like" substance ran from the taps in the south Auckland suburb for three months. Resident Philippe Gauthier described the water at the time as, "cloudy and yellow like urine".

At the time, Watercare spokesperson Sifa Pole said he believed the issue was caused by minerals from cast iron water mains in the area.

"Changes in the flow through the network, for example increased usage or higher flow can cause these minerals to become disturbed."

He said a fire at Māngere Mountain could have been partly to blame, saying there would have been, "changes in network pressure when large quantities of water were used to tackle the blaze".

In 2017, several homes on Eversleigh Rd in Belmont, near Devonport, on the far side of Auckland also had discoloured water issues. On that occasion, the water stained clothes, towels, sheets, and wrecked an expensive bathroom sink, forcing locals to question whether the water was fit to drink.

One local had water from the pipes tested, after having her home plumbing replaced to no effect. The test results showed a high level of manganese and iron, which testing company Aqualab attributed to "severe corrosion of the reticulation pipes", which were also cast iron.

At the time, Watercare put temporary pipes above ground to remedy the situation, until the old cast iron pipes deemed to be causing the issue could be replaced.