Facts about your drinking water

What do you know about your water?

If you're curious about your water and where it comes from, read some essential facts about our drinking water quality and operations.

Most of the drinking water in Sydney, the Blue Mountains and the Illawarra comes from rainwater collected from natural catchment areas. It's then stored in lakes that are surrounded by some of the most unspoilt native bushland in the region - including world heritage national parks.

WaterNSW manages these catchment areas to ensure they can continue to deliver the best quality water for years to come.

WaterNSW's expertise and monitoring ensures they select the best quality source water for us to filter. Warragamba Dam provides about 80% of greater Sydney's drinking water.

Not all of the water is sourced from lakes. In the North Richmond area, we source water from the Hawkesbury River. In times of drought,  Sydney Desalination Plant uses a process called reverse osmosis to turn seawater into drinking water.

No matter where the water comes from, every drop of drinking water is filtered before it's delivered to your tap.
We filter 100% of your water. Experienced operators, state-of-the-art monitoring and computer controls ensure that your water meets the Australian Drinking Water Guidelines. These guidelines  are some of the strictest in the world.

Our filtration plants are run by teams of dedicated and experienced people. They're committed to ensuring that people across Sydney, the Blue Mountains and the Illawarra region have safe, filtered water every day of the year.

We clean our water filters a few times each week to ensure your water quality is always high.

Find out more about water quality and filtration.

We add a small amount of chlorine to your drinking water at our filtration plants to protect you from micro-organisms. It's safe and effective. The amounts we add are informed by the Australian Drinking Water Guidelines.

We try to minimise the taste and smell of chlorine in your drinking water. If you still notice it, let your water stand in a jug or put it in the fridge overnight.

We also use other steps to make sure your drinking water remains safe after it leaves the filtration plant. These include:

  • state-of-the-art leak detection programs
  • secure, covered reservoirs and inspection programs
  • secondary chlorination in the network
  • pressurising the pipes to keep things out.
We continuously monitor your water quality at key steps. 

We work together with WaterNSW to take samples every step of the way from the lake or river, to just outside customers' homes and businesses.

Our state-of-the-art laboratory works throughout the year. We do up to 70 different tests to make sure your drinking water meets the Australian Drinking Water Guidelines.

The  Sydney Water Monitoring Services TM laboratory is one of the leading water testing facilities in Australia. It provides a range of biological and chemical tests.

Our laboratory and field sampling teams are accredited by Australia’s National Association of Testing Authorities.

We're committed to honesty and transparency. If there's ever a threat to Sydney's drinking water quality, we'll work with NSW Health to notify the public immediately. We regularly report to NSW Health on the quality of your water.
Sydney's drinking water is great quality. It's much better value than buying bottled water.

If you live in Sydney, the Blue Mountains or the Illawarra, you pay less than 1 cent a litre for water! However, keep in mind that your Sydney Water bill includes more than water use charges.

Read more about how tap water compares to bottled water in this recent Choice article -  Spinning the bottle.

We add small amounts of fluoride to your drinking water to strengthen teeth and prevent decay.

We do this in line with guidance from NSW Health. There's a lot of research to support this. In fact, the United States Centers for Disease Control and Prevention identifies drinking water fluoridation as one of the top ten public health achievements of the 20th century.

Find out more about fluoride in drinking water from:

Why does your water look or taste different?

Occasionally your water might look or taste a little different to normal. Learn more below.

If you still have concerns, please call us on 13 20 90.

Glass of cloudy or white water clearing from the bottom up

Cloudy water is caused by tiny air bubbles

From time-to-time, the water may appear 'cloudy' when you turn on your tap.

Cloudy water is just tiny air bubbles caused by water of different temperatures entering our system.

This is completely natural, particularly in the warmer months. Your water is safe to drink.

When you fill a glass, the water will clear from the bottom up and should be completely clear in a few seconds. If you're concerned, let the water rest for 30 seconds.


Changes to the colour of your drinking water can happen from time-to-time and are normally safe.  They can happen because:

  • the pipes on your property are old or need to be repaired. Call your local plumber to check the condition of your pipes
  • your hot water service needs to be repaired or replaced.  Check if the discoloured water only comes from your hot water taps. If so, call your local plumber
  • we're working on the water pipes in your area. Check our Water supply & service updates map.

If your water is discoloured, we recommend running the cold water tap for a few minutes to see if it returns to normal.  If it doesn’t improve, please call us on 13 20 90.

If you notice black specks in your water, it's normally caused by the rubber from your tap washers or o-rings wearing out.

This happens most often in taps that you don’t use often.

Please call us on 13 20 90 if you're concerned about this problem.
The taste of your water can change from time-to-time, for various reasons.

Some people are quite sensitive to taste and might sometimes notice metallic, chlorine or earthy tastes and odours.

We need to add small amounts of chlorine to protect the safety of your drinking water. The smell and taste of chlorine will disappear if you put a jug of water on the bench and allow it to stand for an hour - or pop it in the fridge overnight.

If you're concerned by these or any other taste and odour issues, please call us on 13 20 90
Couple with bicycles sitting on grass drinking water

We protect your health by providing locally sourced, clean and safe drinking water.