Creaking infrastructure gobbling up dollars

If any doubt remained over the challenges of failing Three Waters infrastructure in the Hutt (and wider in the region), latest water loss data from Wellington Water (WW) surely drowns it.

It’s an issue that throws sharp focus on the different Three Waters proposals of Labour and National as we head to the polls in October. (See ‘Where did we get to on 3 Waters reform?’)

Wellington Water has recently advised that water loss from Hutt City’s public and private water network for the 2022/23 financial year has been calculated at 46% – a massive jump on what was assessed 12 months ago (20%).

It’s estimated that 37% of the loss is from HCC’s public network, with a further 9% from pipes and taps on private land.

It’s not so much that the pipe network has degraded drastically in 12 months but rather that the information WW has, following the installation of 16 small area meters, provides a more accurate means of assessing water loss.  The figure is still just an estimate but information gleaned from the area meters on night and day use, an improved methodology and independent review, means Wellington Water believes it has significantly increased (effectively doubled) the confidence in the estimates.

One piece of good news: In the last year something like 18.6 kilometres of pipeline have been renewed across the Wellington Water region, with the lion’s share of that – 14.5km – in Hutt City.

HCC’s rates increase is 9.9% for the financial year that started July 1, meaning an annual rise for the average valued residential property of $261.  About half of that ($126) is related to investment in Three Waters infrastructure. 

Hutt City’s capital programme, heavy on critical infrastructure, totals $1.6 billion over the next eight years, which is $277 million more than we previously budgeted for.

But there’s such a mountain of work ahead of us, no small amount of it driven by higher expectations and regulations relating to stormwater, wastewater and the protection of our waterways.

Lower Hutt has more than 90% of the region’s galvanised water pipes – the ones that rust away as they age.  We need to renew some 110km of galvanised piping, at an estimated cost of $125m.


This table of estimated costs of three waters investment needed in the Hutt excludes the Wastewater Joint Venture trunk network, the Seaview WW Treatment Plant and water quality improvements that may be required by new discharge consents.

Around 30% of pipes have reached their nominal useful life and many are in poor condition. A further 20% reach life expectancy in 2050.   Also, a lot are at or near capacity.

The Seaview long outfall pipe is suffering more frequent joint leaks and failures, leading to increased operational costs and environmental impact.  The huge capital expense of renewing it may need to be brought forward.

On Three Waters infrastructure alone, it’s estimated $1.27b is needed over next 30 years to meet projected population growth, and to bring existing networks to ‘target levels of service’.  (The ‘target’ for stormwater, for example, is protection from flooding of habitable floors in 100-year flood that includes predicted impact of climate change, a 20% increase in rainfall intensity.)

Some 18% of this funding – $230 milllion – is already in the 2021-31 Long-Term Plan. The $1b shortfall is in today’s dollars, but it includes a large contingency/risk allowance.

In summary, on average, $35m in additional funding will be needed per year for the next 30 years just to meet likely growth demands.  Developers will be expected to take on a hefty chunk of this via development contributions.

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