The risk of water restrictions has been blamed on the fact that nearly half of the capital's water is being lost through leaks. File photo. Photo: RNZ / Angus Dreaver
Wellington region mayors are warning residents to conserve water where possible this summer, despite positive usage modelling.
The likelihood of Wellington, the Hutt Valley and Porirua being plunged into level three water restrictions reached as high as 60 percent last summer.
Wellington Water largely attributed the risk to nearly half of the capital's water being lost through leaks.
In February, at the end of that summer, water regulator Taumata Arowai asked for a "step change" from Wellington Water to avoid similar risks to the water supply.
The two agencies agreed that if water demand was reduced by 7.4 million litres per day in February 2025, it would reduce the risk of an acute shortage.
Wellington region may face summer water shortages
Modelling has indicated Wellington Water was trending towards reaching that goal, with demand being down 9 million litres per day year on year.
Wellington Water acting chief executive Charles Barker said as leak repairs and water loss reduction work continued, they expected demand to decrease.
Lower Hutt mayor Campbell Barry said the region was tracking well, given the demand reduction was being led by fixing leaks.
But Barry said the latest modelling did not mean people should get complacent about water use.
"We're not out of the woods, even though things are looking better than what they did last summer when it comes to reducing our consumption or water loss, so it's going to be important that we still [are] really conscious of the water we do use."
He said the region would be facing the risk of water restrictions in summer for years.
"We are dealing with a network that is pretty old and is leaking like a sieve, to be quite frank."
Porirua mayor Anita Baker said despite the likelihood of severe water restrictions going down, there will probably be some measures put in place.
She said this included asking people to conserve their water when brushing their teeth or using the shower.
Baker said the advice around restrictions last year had educated people on the problem.
"I think people are prepared and people are a lot more patient about it now because they do realise the severe problem."
Wellington mayor Tory Whanau said as the region avoided restrictions under last year's dry summer, she was hopeful they could steer clear of them this year.
Whanau said Wellington City Council had 300 water tanks for residents arriving in two weeks, with the goal of keeping their stocks as consistent as possible.
Wellington Water expects to have a clearer picture of this summer's risk when NIWA releases modelling next month.
Less water leaking from the Wellington region's pipe network
New data from Wellington Water shows in 30 June this year the total amount of water being lost through leaks was 41 percent.
That compared to 44 percent in July the year prior.
Acting Wellington Water chief executive Charles Barker said the result was a reflection of increased funding from their shareholding councils being made available in the second half of the financial year, and the associated increased leak repair work starting in late January 2024 or later.
Barker said with ongoing funding for leak repairs, they expected that the region will see a further reduction in annual water loss.
He said the backlog of open leaks had also reduced by around 57 percent over the past eight months with 1,261 open leaks on 26 August down from over 3,000 in January 2024.
The new data also comes as the region prepares for the upcoming Summer season, with level one restrictions coming into force in the Hutt Valley, Porirua and Wellington on 28 September.
Those rules mean residents can only use sprinklers every second day.