Recent rainfall has seen Auckland’s total water storage level reach 80 per cent, easing pressure on the city’s water supply.
In July and August the dams in the Waitakere Ranges filled steadily as they received 495mm of rainfall. The dams in the Hunua Ranges are much bigger and the catchment received less rainfall in the corresponding months (376mm in July and August), but now total storage has reached a more comfortable level as we enter spring.
Watercare head of water value, Roseline Klein is pleased to see the turn-around: “We’d like to thank Aucklanders for answering our call to be waterwise in response to the record-breaking dry weather. In July and August, water use dropped by 2.5 per cent compared to June and we’re very grateful to everyone who reduced unnecessary water use.”
We encouraged Aucklanders to take simple steps such as reducing shower times and only running washing machines when they were full. The free water advice service delivered by EcoMatters Environment Trust experienced a 24 per cent increase in referrals over July and August from residents wanting to book an in-home water audit service, compared to the same time last year.
Over the dry spell, water sources were carefully managed. Production from the Waikato River and Onehunga Aquifer were maximised to reduce demand on the dams. When the rain arrived, production at Huia Water Treatment Plant was boosted as the western dams replenished.
The current total storage is still 10 per cent below the historical average for this time of year but more rain is on the way.
Metservice is forecasting rain or showers for the next 10 days, with a cold front expected to arrive on Sunday -Monday.
- The dams in the Waitakere Ranges are significantly smaller than the dams in the Hunua Ranges. For example, the capacity of all five dams in the Waitakere Ranges is less than the capacity of the largest dam (Mangatangi) in the Hunua Ranges.
- In the last six weeks (up to the end of August), Auckland’s dams received rainfall equivalent to the first six months of the year.
- On 1 July, the city’s total water storage was only 59.2 per cent after recording-breaking dry over the first six months of the year.
Left - before (June 2019) and, right - after (5th September 2019) scenes of the valve tower in the Mangatawhiri Dam, Hunua ranges.