Trunk mains: fix your water pressure

Problems with your trunk main water pressure? Here’s what you need to do.

Being connected to a water trunk main can present you with water pressure and water quality problems. Here are some steps you can take.

If your property is located between a water treatment plant and the reticulated town supply, your water is safe to drink, but the pressure can be very unpredictable. 

If your property is located between a water source and a treatment plant, you have the compounded problem of water quality and erratic pressure. 

If you are unsure where on the trunk main your property lies, contact us. 

Water pressure problems explained 

Let’s say you run a tap at the same time we pump a large amount of water from a treatment plant to a reticulated system head. In this instance you would get a sudden increase in pressure that can be messy at best, and at worst it can ruin home appliances such as washing machines and dishwashers. 

The opposite can also happen, where pressure can unexpectedly drop, or disappear, at a time when you may need water the most. 

Unlike reticulated systems, trunk main connections cannot be isolated. This means water can be turned off without warning for many customers if urgent work on a trunk main is needed. 

Fix your water pressure 

This can be done in two ways: 

  • Pressure reducing valve: Contact your local plumber to ask about fitting one of these simple and inexpensive devices to your incoming water supply. While they work great for preventing those unexpected bursts of water, they offer no solution to little or no water pressure.
  • Tank and pump: Installing a small tank and pump is the best way to deal with too much, too little, or no pressure at all. Connecting a float valve to a tank will ensure your tank automatically refills as you use water in your house. There is no need for a large tank, just something sufficient to see you through any unexpected times when we need to work on the trunk main.

How to set up a tank, pump and valve system

Our recommended home set-up to end your water pressure worries.

  1. Your connection to the water trunk main
  2. A pressure reducing valve (PRV) is installed at your water meter
  3. A small water tank with an airlock and float valve is installed, ensuring your tank never overflows or feeds back into the system
  4. A water pump delivers water to your home without any pressure fluctuations.

Image showing how to set up a tank, pump and valve system.


To learn more about improving the quality of your water supply, click on the 'Is my water safe to drink?' button below:

Water flowing over rocks.

Is my water safe to drink?

Get the lowdown on the quality of your water and how to make it safe to drink.

Find out more

Installation of a water flowter.

Water trunk mains explained

Everything you need to know about drawing water from one of our water trunk mains.

Find out more

Water pipes being laid in a trench.

Can I connect to a trunk main?

Trunk mains have water quality and pressure problems, so we currently don’t allow new connections.

Find out more

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