Pressure Management Project

The Water Pressure Reduction Pilot is being done in parts of the water network in Brooklyn, Johnsonville and Melrose.

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.

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.

The reduction in pressure should not affect the operation of any household items, as the minimum pressure will be above the required minimum.

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.

No, all existing fittings should operate under the reduced pressure.

Contact Wellington Water on customer@wellingtonwater.co.nz (04 912 4470).

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.

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.

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. 

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.

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.

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. 

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 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.

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

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:

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.