‘Bottomless’ – the cost to fix water woes
Millions of litres of sewage have spilled into Wellington Harbour and a broken pipeline means sludge is being trucked to the Southern Landfill 24 hours a day – but there is a deeper problem.
Wellington’s pipes are in the worst condition of any major centre in New Zealand, according to Water NZ. Thirty-three per cent of pipes in the region are in poor or very poor condition and at an average age of 51 years, they’re also the oldest pipes in the country.
That’s leading to more leaks across the city every year. In 2019, Wellington Water recorded 16,000 leaks, up from 10,000 in 2014.
The average repair time for leaks is 21 days, which is outside of council targets.
Approximately 20 per cent of treated water never makes it to taps – though in reality the council has no idea exactly how much water is lost, because there is no reliable data.
Wastewater overflowing into public places is now so prevalent that Wellington Water has set a baseline anticipating 43 incidents per month. The strain on the ageing infrastructure became far more intense after the 7.8-magnitude quake in Kaiko¯ura in 2016, suggesting that was partly to blame.
Wellington City Councillor Sean Rush said the scale of the problem was forcing the council to take a new approach when it comes to prioritising which pipes to fix.
‘‘What we’ve done previously is to service and replace pipes based on their age, but we think the focus should now be on pipes where a break would be of high consequence for the city.’’
Replacing the entire network would not be possible due to costs and disruption.
With the council already spending a third of its annual budget on water systems, its not clear what more can be done to maintain and upgrade the network.
‘‘If we’re not able to manage the system like other cities with similar budgets and similar issues, we’ve got to ask ourselves if we’ve got some issues,’’ Rush said.
Councillor Iona Pannett said it was impossible to estimate how much a network upgrade would cost.
‘‘It’s bottomless, the amount of money you would need. There’s so many issues in the water space that we need to fix.’’
‘‘You could spend the whole council budget on water without too many difficulties.’’
A major cash injection in 2018 had focused on the stormwater system to reduce the impact of flooding, but the drinking and wastewater systems lagged behind.
Rush said the amount of drinking water lost to leaks was starting to put a strain on the supply coming from the Hutt River.
‘‘We’re supposed to get 50-80,000 people over the next decade and we need to supply water to them. We could do that if we just fixed all our leaks.’’