The levels of water in Auckland's dams are expected to drop below 50 percent full after significantly low rainfall throughout autumn.
At this time of year, Auckland's dams are normally 76.4 percent full but as of Thursday, they have dropped to just 50.26 percent.
The drop is due to low rainfall, with eight of the past 12 months reporting lower than average monthly rainfall. The last time Auckland had equal or more than normal rainfall was in November 2020.
Watercare chief executive Jon Lamonte said with no rain expected until next week, dam storage is likely to drop below 50 percent by the weekend.
However, he said Watercare has put in work to add resilience to Auckland's water supply and prepare for a dry year, after a series of failings by the water management agency in 2020.
"Since restrictions were put in place last May, we have built two new water treatment plants in Pukekohe and Papakura, and boosted production capacity at our Waikato water treatment plant.
"Work on our new water treatment plant in Waikato is also progressing steadily, and when the first stage is completed this winter it will provide up to 50 million litres a day. This provides a good safety net if the rest of the year turns out to be drier than anticipated."
Auckland Mayor Phil Goff agreed, saying although the dams are approaching the 50 percent mark, "we are in a significantly more resilient position than last year".
"Had we not taken these steps to increase supply and reduce usage and leaks, our dam levels would likely now be approaching 30 percent - a far more serious position than we are currently in.
"However, we do not know how much rain the winter will deliver so it's important that Aucklanders keep up with their water savings efforts."
Auckland residents are being urged to take shorter showers to help with the water supply.
The city was on the cusp of a water emergency last year amid the region's worst drought in 25 years.