Photo: Wairoa Dam in the Hunua Ranges (6 April 2021) is currently 57.73 per cent full.
Auckland’s dams are edging closer to the half-full mark, but the city’s water supply is in a stronger position this year thanks to new water sources and a significant reduction in consumption.
The total dam storage level is currently 51.9 per cent (ironically almost the same figure as last year when it was 51.89 per cent), and normally at this time of year it would be about 77.3 per cent. However, if the forecast rain due to fall at the weekend (April 10-11) and next week misses us completely and our dam levels drop below half full, there’s no cause for alarm.
We are in a stronger position than we were a year ago thanks to the new water sources that have been brought online, and the phenomenal effort Aucklanders are making to reduce water usage. Together, we have become more resilient as a city. This is proof that a successful drought response requires action from the water provider and the affected community. Now, we just need to keep up the good work.
By increasing our take from the Waikato River, reinstating an underground aquifer in Pukekohe and upgrading the Onehunga Water Treatment Plant, we have reduced our dependence on our dams. Work is also progressing at pace on the first stage of the new Waikato Water Treatment Plant which will deliver up to 50 million litres a day (MLD) when it goes live this winter. We brought this project forward as part of our drought response, and it will provide a safety net if the forecast rainfall doesn’t show up. It’ll also allow us to minimise our take from our dams while they recover from the drought.
River and underground sources are still dependent on rain but are more resilient to drought because their catchment areas are far greater. For example, Waikato River’s catchment area is more than 14,000 square kilometres, while the combined catchment area for Auckland’s water supply dams is 158 square kilometres.
Later this year, the permanent Papakura Water Treatment Plant will boost supply by another 6 million litres a day (MLD) and an upgrade of the Waitakere Water Treatment Plant will lift capacity by 8 MLD.
By the end of this year, we will have increased our peak supply by more than 100 MLD and mostly with non-dam sources. That’s a huge amount of water and would provide for 330,000 people – an equivalent size of Palmerston North, Tauranga and Hamilton combined.