Risk to hospitals, rest homes if Wellington runs out of water

Friday, 8 December 2023

A burst pipe sends huge plume of water spouting over Aro St in Wellington. Wellington Water admits it is losing the war against leaks and is seeking emergency powers to take extra water from catchments.

Wellington Water is warning that if the region’s water runs dry, it cannot guarantee it will be able to prioritise the supply to hospitals and rest homes.

With the number of leaks increasing steadily, it is predicting a one in four chance of an “acute” water shortage over summer.

Given the poor state of the water network, Wellington Water said that if that happens it may not be able to prioritise the supply to hospitals and rest homes.

“Given the nature and condition of the existing infrastructure, it is not possible for WWL to have confidence in being able to prioritise uses (i.e. more sensitive uses such as hospitals or rest homes) or areas (where there is a high concentration of sensitive uses) by simply limiting, turning off or diverting supply.”

A Wellington Water team fixing a leak in Maungaraki, Lower Hutt. (File Pic)

The stark message about the severity of the situation facing the region, is contained in a report to be considered by the Wellington Water Committee on Monday.

As well, Wellington Water is seeking emergency powers to take more water from local rivers and aquifers because of the looming acute water shortage.

That could mean parts of the region without water and with boil water notices.

The Haywards reservoir, which supplies Porirua and Johnsonville/Tawa, would fail first in a dry summer. In the central city, the Carmichael reservoir was likely to fail first and backup systems would supply water for about only three days.

Late last month Wellington Water “formally notified” Greater Wellington Regional Council and Taumata Arowai, the national water services regulator, that Wellington could run dry.

It is seeking their support to declare a “water emergency” giving Wellington Water the authority to take more water from various catchments at a rate above that allowed in their consents. The extra powers would only come in to force, once the situation becomes serious.

Taumata Arowai can declare a water emergency under the Water Services Act if it believes there is a serious risk to public health, including insufficient supply. Taumata Arowai then has access to a range of powers to manage the situation.

Taking more water from the Te Awa Kairangi/Hutt River would not be a popular decision. Local Māori have expressed on-going concerns about the impact of taking water from the river. There is also a widely held view that too much water is being taken already and is a contributing factor to the increasing number of toxic algae blooms.

The pipes near Diane Calvert's home in Karori were recently replaced, allowing the councillor a glimpse of the rusted insides of Wellington's aging drinking water system.

There are just under 3000 active leaks across the region. Upper Hutt is losing 52% of its water to leaks and regionally the figure is 44%.

Wellington Water has been concentrating on communication, emphasising the need to save water, as it prepares for a predicted dry summer. Water use, however, remains high compared with other parts of New Zealand.

Although Wellington Water remains committed to fixing the leaks, the report said it lacks funding and the number of leaks had grown steadily since 2015.

The report notes that Wellington Water had introduced a range of “risk mitigation activities” but the situation remains serious.

Wellington Water wants to take more water out of the Hutt River as the region runs low on drinking water.

“At the root the risk is caused by the very high level of water loss in the network, and significant funding will be required to control the risk.”

It asked Greater Wellington and Taumata Arowai to “exercise their powers” and allow Wellington Water to take more water than their consent allows from catchments across the region.

The letter said there is an “imminent risk” that it will not be able to supply drinking water and its best option is to take more water from the catchments.

“WWL is placed in an irreconcilable position when the demand for water exceeds the supply, and it is not able to provide sufficient quantity of water (and which may cause the drinking water to be unsafe), unless it takes more water than the minimum flows allow for under the conditions of the existing resource consents.”

It also warned that with leaks increasing and an ageing water network, its ability to supply drinking water would continue to decline for years to come.

– Correction: Paragraph 11 has been amended to reflect that a drinking water emergency under the Water Services Act is different to a state of emergency under the Civil Defence Emergency Management Act. (Amended December 12, 2023, 10.55am)