(File photo.) Photo: 123RF
Watercare is still working to flush the network after West Auckland residents reported discoloured tap water.
The reports came from households in Kelston, Henderson, Rānui, Glen Eden and Oratia on Friday night.
Watercare posted on Facebook on Saturday morning, saying that crews were flushing the network to clear it.
"We understand many of you still have discoloured water running from your taps. Our crews are on the ground in your communities and are continuing to flush the network to get rid of the discolouration. Thank you for your patience.
"Just a reminder that while the water flowing from your taps looks different, it is still safe to drink. Our rigourous water sampling programme confirms that all the water we supply is compliant with the Drinking Water Standards of New Zealand."
The agency said discoloured water was most often caused by naturally occurring minerals, such as iron or manganese, which build up in pipes.
Water could sometimes take on a yellowish tinge as those minerals were stirred by a change in water flow.