Pressure Management Project
On behalf of Wellington City Council, we are working to minimise areas of excess water pressure in the water distribution system to reduce leakage and water consumption and help increase the life of our water network.
If you have any questions about this work, please contact:
Wellington Water, 04 912 4400
Current Status
We have completed the physical works on the pressure management project which recently took place in parts of Brooklyn, Johnsonville and Melrose.
This pilot project involved installing pressure reduction valves in parts of the water network. This work just prior to December 2023. Please see the 'background tab' above for more information.
We're currently working on analysing the results of this pilot project and we'll share key insights and results once available.
If residents have any queries regarding the above work, please contact our Customer Hub (customer@wellingtonwater.co.nz), or on 04 912 4470. You can also contact Wellington City Council on 04 499 4444.
What's happening?
Wellington Water has an ongoing programme to improve pressure management across the region. Pressure management is usually done by installing pressure reducing valves to reduce water pressure within areas of the network. This is common both internationally and nationally, to reduce water use and loss, extend the life of pipes and reduce the number of leaks.
Three projects will serve as pilot studies to improve how similar projects can be delivered, by refining the costs and benefits of pressure management within the region, and informing further pressure management opportunities. Modelling indicates that pressure management within these zones may provide water savings of up to 300,000 litres per day, and reduce the number of new leaks by as many as 40 per year, as well as extending the life of the pipework.
FAQs
Where are the Water Pressure Reduction Pilot Projects being done?
The Water Pressure Reduction Pilot is being done in parts of the water network in Brooklyn, Johnsonville and Melrose.
At what phase are these pilot projects?
The work installing Pressure reduction valves started just before the December 2023 holiday period.
We’re now in the process of reducing water pressure in Brooklyn and Johnsonville. Residents should not notice a significant difference in water pressure in their showers, taps and hoses etc. The pressure will be reduced gradually, only to parts of each suburb and to varying levels too.
We’re also reducing water pressure in parts of Melrose (Houghton Bay) too. This work is scheduled for around March/April 2024.
What happens at the end of these pilot projects?
The results of the pilot project will be shared, once analysis is complete. If successful, the pressure reduction will be implemented permanently in these three areas.
Will the reduction in pressure effect the operation of any of my household items?
The reduction in pressure should not affect the operation of any household items, as the minimum pressure will be above the required minimum.
Will the pressure reduction affect my current installed PCV?
There is a risk that the pressure reduction may require recalibration of some private PRV’s (pressure control valves). Upon making the pressure change to the network, Wellington Water have provided a plumber on standby to respond to any customer complaints, at no charge to the customer.
Do I need to install new fittings (taps, shower head, garden hose connectors) once the pressure is reduced?
No, all existing fittings should operate under the reduced pressure.
What should I do if I encounter a sudden drop in pressure?
Contact Wellington Water on customer@wellingtonwater.co.nz (04 912 4470).
Will you be inspecting individual properties or taking any pressure measurements on site?
Individual property pressure measurements are not initially required as pressure reduction covers the overall network. Investigation is not done on a house-by-house basis. We have completed hydraulic models that indicate by how much we need to reduce excess pressure, and we will monitor flows and pressures in the wider network to assess the operation of the pressure reduction.
If problems arise with your water pressure after the pressure reduction has been carried out, please let us know. We will then assess the need for individual property measurements.
Where will the PRVs be installed and what’s involved?
We will be installing the PRVs at sites off the road and away from residential properties where possible. We expect each installation to take 1 – 2 weeks and it will involve a brief shutdown of the water supply of less than 4 hours. We will let you know in advance before that happens.
We have low water pressure where we live. Will this project make it even lower?
You may experience a slight reduction in water pressure. However, it will always remain within Wellington Water pressure guidelines. We will also be working with customer feedback during the process of pressure reduction to ensure service levels are not adversely affected.
We have a PRV installed in our home. What do we need to do?
Nothing! We will only be lowering excess upstream pressure which should not adversely affect your personal PRV. However, if any issues with your water pressure are experienced during the project, please let us know.
What happens if our PRV has to be replaced or removed, who covers the costs?
We do not expect that your personal PRV will need to be replaced or removed as the project PRV will function independently- the pressure reductions are not compounded. The pressure downstream of the PRV (i.e., at your house) should remain the same, although you may experience a slight reduction in water pressure if your property is at a higher elevation. However, it will always remain within Wellington Water pressure guidelines.
If any issues are experienced during the pressure reduction, please let us know.
I don’t know whether we have a PRV installed or not? Do I need to know?
It shouldn’t matter if you have a PRV installed or not as we do not expect any issues for existing PRV’s. You do not need to know if you have a PRV installed for the success of this project as the pressure change will be the consistent with or without one.
We have a siphon hot water system that relies on mains pressure to siphon hot water from our water tank. Will the project affect this?
The pressure supplied to households will still remain within Wellington Water guidelines and should not significantly affect the operation of hot water cylinders. We will be working with customers during the pressure reduction, seeking feedback to monitor and if need be manage any effects.
We have PRVs on a low-pressure hot water cylinder in our home. How will the project affect us?
We do not expect that personal PRVs will be adversely affected as the project PRV will function independently- the pressure reductions are not compounded. The pressure downstream of the PRV should remain the same, although you may experience a slight reduction in water pressure if your property is at a higher elevation. However, it will always remain within Wellington Water pressure guidelines.
We have a fire sprinkler system in our house. Will the project affect that?
Please contact us if you have a sprinkler system in your house or property and we will arrange a site visit to check your system
Where exactly is the pressure reduction work in Johnsonville?
This area is located on the western part of Johnsonville. The topography is relatively hilly, with properties located between 175m and 265m above sea level.
The pressure in the Johnsonville West PMA is controlled at two points:
- The Broderick Road Pump Station (head approximately 290m during pump operation)
- The Johnsonville West Reservoir (287m TWL), supplied by the Broderick Road Pump Station via the distribution network.
Impacted area:
Will there be a reduction in pressure at my property in Johnsonville?
The pressure reduction work is taking place in Johnsonville West (see map below). If you’re in this area, water pressure will be reduced to a pressure rating of 25 meters.
The actual drop in water pressure residents will experience does depend on the exact location of their property, its age and the current pressure reduction valves you have installed (i.e. older properties furthest away from reservoirs, at the bottom of hills may notice the water pressure drop the most. This depends on the pressure reduction valve currently installed at a property.)
The pressure range applied is within the acceptable range set for new housing developments, which is within the range of 25-90 meters.