Improving Porirua’s Water Supply Resilience

The Team from Wellington Water

Like the rest of the Wellington region, Porirua’s water supply is vulnerable to seismic activity and needs to improve its water supply resilience.

This is the message from Porirua City Council and Wellington Water who are encouraging residents to be prepared for an emergency and embarking on plans to improve Porirua’s water supply infrastructure.

Porirua has no water sources of its own and is supplied with water from the Hutt Valley by a single pipeline. In addition, the Ohariu Fault runs through the middle of Porirua, separating residents on the west side from the rest of the city. This makes Porirua particularly vulnerable to extended water supply outages.

“Improving Porirua's water resilience starts at home” says Laurence Edwards, Wellington Water’s Acting Chief Advisor, Potable Water.

“We are encouraging everybody to make sure they have 20 litres of stored water, per person, per day for at least seven days.”

Residents can purchase 200 Litre tanks directly from Porirua City Council.

Planning is also underway to improve Porirua’s water supply infrastructure.

“We have identified that two new reservoirs are needed in Porirua - one on each side of the Ohariu fault line.”

The reservoirs will improve the city’s resilience to an earthquake, reduce disruption on a day-to-day basis and provide for future population growth.

On the east side of the Ohariu faultline, a new reservoir (11.3 million litre capacity) is proposed at Aotea next to the two existing water reservoirs. This reservoir would service the wider Kenepuru, CBD and Ranui Heights, Porirua East and Cannons Creek areas.

On the west side a smaller reservoir (approximately 3-5 million litre capacity) is proposed in the general Takapūwāhia area. This reservoir would service the wider Titahi Bay area.

“Originally, we were looking at one site for a single reservoir. However, it makes more sense to have two reservoirs – one on either side of the fault line - to lessen the risk that parts of the city are left without water supply for long periods after a disaster situation” says Laurence Edwards.

Wellington Water is currently talking with some of the directly affected stakeholders and will be engaging further with the community in early 2018.

The proposed Aotea site is likely to progress first and our engagement will be focused with the Aotea community in early 2018. This will include face to face meetings and open days where there will be opportunity to see details of the proposed Aotea reservoir and provide feedback.