Critical water shortages: Aucklanders urged to cut consumption after floods

Friday, 10 March 2017

Watercare's dams in the Hunua Ranges are contaminated with silt in the wake of heavy rain.

A boil water notice could be issued for Auckland if residents don't urgently reduce their water use, Watercare says.

The Ardmore Water Treatment Plant - which is sourced from four water storage dams in the Hunua Ranges - is treating 50 per cent less water than usual in the wake of the storms that battered the region this week.

Dam water flowing into the plant post-storm contained a lot of silt due to slips and erosion, making it more difficult to treat.

Watercare spokesman Mark Bourne holds silted floodwater from the Hunua Dam.

On Friday, Watercare said if residents did not cut their water consumption by 20 litres per day until the end of March, partially treated water might have to be released into the region's supply.

* Hunua farmer loses cattle and fencing as water sweeps through property

* Flooding, slips and heavy rain lash top of North Island**

Silted floodwater from the Hunua Dam compared to treated water.

That water 'would not meet New Zealand's stringent water quality standards', spokesman Mark Bourne said.

A sustained period of dry weather was required in order for the water in the dams to settle so that the plant could resume full activity.

Watercare's website had been updated to reflect water savings targets and advertising would be rolled out over the next week, Bourne said.

Saving 20 litres just meant spending three less minutes in the shower each day.

'The savings are achievable, we all just have to play our part . . . the storm is still top of mind, there's no need to water the garden.'

The shortage would not affect water pricing, Bourne said.

The water was currently 'safe to drink straight from the tap' - the only issue was the quantity available.

The storm was an 'extraordinarily rare event', and cyclones and water cyclones had never had this sort of impact on the water supply, he said.

And he thought scientists and water analysts would eventually confirm how rare the storm event was.

'I've been in this industry now for 27 years but I've never seen an event like this.'

He said Watercare had worked through a number of significant cyclones over the years but never any that had such an effect on water quality in the Hunua ranges.

'The last time there was a need for any water savings in Auckland was 20 years ago [in] 1994.'

Auckland experienced a severe drought that year, which later saw Watercare call for the drought security standard to be lifted and water from the Waikato River to be piped into Auckland's water supply.

Watercare staff were working 24 hours a day to manage the issue and production from the region's four other water treatment plants had been maximised, the organisation said.

HOW MUCH IS 20 LITRES?

Twenty litres of water is equal to two standard water buckets.

Water can be saved by cutting shower times, turning off taps while brushing teeth and only running dishwashers and washing machines when full, Watercare said.