A Wellington Water report has recommended universal water metering in every Wellington home.
Water meters in every house and daily water-use reports will be necessary for Wellington to avoid drought-like water shortages.
A new Wellington Water report prepared by Ernst Young and Beca recommended the region adopt a $144 million advanced metering infrastructure, with daily water consumption feedback and leak alerts provided to residents via a smartphone app.
The report warned leaks and over-consumption could put the region’s water stock under severe strain, and potentially cost hundreds of millions to fix.
“Without intervention or investment, demand for water will continue to grow and expose the community to risk of severe water shortage,” the report said.
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At the current rate of water use and population growth, the amount of water needed to meet drought resilience water levels could exceed supply by as early as 2026.
That would lump councils with a $250 million bill to build a new water supply lake in Upper Hutt, a cost which councils would struggle to afford on top of other urgent infrastructure spending.
A 10 per cent reduction in water consumption would allow councils to defer building a new water source for 12 years, Wellington Water modelling found.
Wellington uses through 370 Litres of drinking water per capita each day, including commercial use and water lost through leaks
Around two-thirds of that water (227 litres) is estimated to be residential use, about 70 litres per day more than Auckland, though a lack of metering means Wellington Water does not know exact figures.
Around 20 to 30 per cent of all drinking water in Wellington is estimated to be lost to leaks before it reaches the tap, around 33 million litres a day.
Residential water metering was seen as an important mechanism to reduce consumption, both by identifying leaks and encouraging people to use less water at home.
The “do maximum” option recommended by the report was estimated to cut residential consumption by 2.5 per cent and reduce water lost through leaks by 7.2 per cent.
The recommended option would come at a cost of $144 million, but was preferred because it would have a net benefit of $138 million, making it near break even.
Other options considered were cheaper, but had proportionately fewer cost benefits.
The report did not explicitly consider whether to charge residents for water at a volumetric rate, but noted that all the options considered would be economically viable if…