Orchard Hills Water Filtration Plant

Orchard Hills Water Filtration Plant filters rainwater collected in the stunning Lake Burragorang, which sits behind Warragamba Dam.

WaterNSW’s monitoring expertise ensures the best quality source water is selected.

We then filter 100% of your water to make sure it's safe to drink straight from your tap.

Orchard Hills

Orchard Hills Water Filtration Plant filters 120 million litres of water a day in summer!

Want to visit a water filtration plant?

Come behind the scenes and see how we protect public health by providing safe, clean drinking water.

We offer excursions and technical tours to high schools, universities and community groups.

Request an excursion.
Location Orchard Hills
Population served 200,000 people
Areas served Greater Penrith, including St Marys, Emu Plains and the lower Blue Mountains. Occasionally, water from Orchard Hills may be pumped further up the Blue Mountains for emergencies, like bushfires.

Find out where your water comes from in our water network.
Source water Warragamba Dam
Average amount of water filtered each day in winter 65 million litres
Average amount of water filtered each day in summer 120 million litres
Maximum capacity 215 million litres
Year the plant was built 1993
Treatment type Direct filtration

Find out more about the plant in Orchard Hills technical data.
Orchard Hills flow chart

Filtration flow chart. Select the flow chart to see a larger version.

Our water filtration processes can be different at each of our plants. We tailor the process to suit the quality of incoming water.

Orchard Hills receives water from the local, natural catchment of Warragamba Dam. Because this water is high quality, we use a modern filtration process called direct filtration.

Direct filtration means the water can be filtered straight away and doesn’t need lots of additional treatment steps before or after filtering. It also uses less chemicals and energy than other types of filtering processes.


Fine screen

We use a fine mesh screen to remove debris, like twigs and leaves from the water.

The mesh screen acts like a sieve, trapping the debris as the water passes through.

Rapid mixing

Rapid mixing

We add solutions to the water to aid the filtration process.

The solutions:
  • adjust the pH
  • make small particles ‘stick’ together to form larger ‘flocs’, making them easier to filter out.

We use a large, rapid mixing paddle to spin the water around very quickly and mix the solutions.


Dual media filter

We use filters made of tightly packed beds of sand and crushed coal to trap and remove the floc.

We clean our filters several times a week and continuously monitor their performance to ensure your water quality always remains high.

Learn more about Drinking water filtration.

Protecting the quality

We carefully balance the pH of the water.

We add small amounts of chlorine to protect the water from harmful pathogens, keeping it safe for us to drink.

As a final step, we add small amounts of fluoride to the water as a safe and effective way of preventing dental decay. It’s not part of the filtration process, but is added under the advice of NSW Health.

We don’t just want to provide safe water, we want to provide great water!
We take many steps and work around the clock to produce high quality drinking water.

It all starts with collecting the best quality water sources. We then filter your water to meet the Australian Drinking Water Guidelines. These are some of the strictest in the world. We clean our filters several times a week to ensure your water quality is always high.

We check and assure the quality with continuous monitoring at key steps. This includes the catchment, water filters and the water supply network.

On top of this, we do up to 70 laboratory tests all the way from our water filtration plants to customers’ taps. This confirms your drinking water is high quality.

Learn more about water quality and filtration.


We continuously monitor water quality.