How Drinking Water Gets To And From Your Home

“I can’t believe there is so much traffic.” said the apprentice staring out of the widescreen of the work truck. I from the driver’s seat nodded in agreement. He was right – a column of cars stretched out in front of us into the distance.

It had been a long day starting with an excavation to replace a fractured water service in Cronulla, then it was off to Sylvania to install a new water heater at a private address.

Although I had been pleased with the outcome of both of these jobs and our customers were satisfied, I was feeling weary. The temperature had been an energy-sapping 43 degrees for most of the day and even now in the late afternoon it still hovered around 30 degrees, so all I wanted to do was get home have a nice cold drink and a shower. Looking back out at the traffic I bet each of those commuters’ had similar thoughts and intentions on their minds.

Fresh Drinking Water – A Little Miracle of Daily Life image7

It’s funny to think that Sydney, the city I choose to live in is ranked the 31st largest in the world with a population of 4.9 million residents, and that number is growing annually and yet to survive iconic city with its beautiful harbour, stunning beaches, and world-famous bridge, each and every one of us need on a daily basis a basic equipment of life.

I’m sure you’ve guessed it fresh drinking water, and a way of getting it to our houses and then safely disposing of it as waste.

Yet most of us go about our daily business without giving it a second’s thought. In the morning, whether by turning a handle, pressing a button, or lifting a lever, we fill up our kettles form the tap to make a drink, doesn’t matter if you drink tea, coffee, smoothie, or plain water, you turn on the tap and expect and take for granted that clean fresh drinking water will appear as if by magic.

And most of the time it does, then if like me after my coffee with two sugars (which is my choice of beverage to start the day) I have a shower before setting off to work.

Then there are plenty of other things we use water for thought the day. Whether by machine, or by hand we wash our clothes, water our gardens, flush our toilets, cook our food, wash our cars, mop our floors, and when we add another magic ingredient gas, give our children hot baths.

How Water Gets To Your Home

But how does all this work? And who are the guys behind the scenes keeping this all going? How does this necessity of life arrive at the tap?  The water we drink starts its life up in the hills and mountainous areas, flowing naturally into catchment areas. To harvest nature’s supply. Sydney Water has ten major and eleven minor dams which collectively store 2500 billion litres of water!!, a vast amount until you consider that Sydney consumes around 1300 million litres per day.

Warragamba dam supplies the majority of water to Sydney, along with the desalination plant at Kurnell.


Warragamba dam

The Role Of Pumping Stations

But to get the water to your tap it first has to pass through pumping stations and filtration plants. To do this there is a mind-boggling amount of pipework involved. There are  21,000 kilometres of pipes – enough if laid out end to end to cross the Pacific Ocean to the USA and back again!!

First, it has to be pumped to your regen, then others pump it to the suburbs then again to the neighbourhoods before finally reaching its destination in your street.

So now you have your drinking water “Hey presto” But that’s only half the story. So now how do we dispose of the wastewater which we have used?

How Wastewater Is Taken Away

When we pull out the plug from the sink or turn off our shower tap, hopefully, all that wastewater disappears from view down the plug hole forever and that’s that.

But in fact, it’s only the beginning.

Underneath our streets and houses lay a vast labyrinth of interconnecting tunnels. There are 25,000km of wastewater pipes owned by Sydney Water along with another 20,000k m of wastewater pipes owned by customers on their private land.

There are several types of systems operated by Sydney Water. Depending on where you live is what you get.

For low lying communities like Kurnell, they use a vacuum system and at Stanwell Park, they use the pressure system relying on individual pumps.

The third and most common type is the gravity system, either the outdated combined type which carries stormwater and wastewater combined, or the more modern sentry type which carries wastewater only. This is the type we are going to concentrate on.

Sentry Type Wastewater Systems

When your wastewater disappears down the sink waste pipe, it will travel downstream along the house line underneath your property. It is then discharged along with all the water from other houses in the street into the main sewer located under the road. image9

These are sometimes known as submains.

From there using gravity it will continue on its journey until it’s directed into a much larger sewer, sometimes referred to as trunk mains.

Trunk mains are very large sewers can run for many kilometres underground.

The longest in Sydney travels from Blacktown to North Head – it’s close to 50 km long.

Because this system relies on gravity it needs fall, consequently, some of these mains are located very deep underground, the deepest is 100m below East Turramurra.

When The Gravity Stations Can’t Go Deeper

What happens to gravity systems when they aren’t able to run any deeper, either due to the rock substrate, or the water table?

Well at this point there will be a lift station to pump the wastewater to a higher elevation to continue its journey along another gravity pipe, or if necessary, via a forced main which by using pressure will force waste along in the desired direction until it reaches a wastewater treatment plant.


Forced Main

Wastewater Treatment Stations


Now what happens at wastewater treatment stations could be a topic all by itself. Basically, large items are removed.

Sand, mud and grit are removed.

Oxygen is then added to the water along with chemicals that help break down any toxins and organic matter.

Sydney Water owns and operates 16 of these plants which collect 13 billion litres of wastewater from over 1.8 million homes daily.

North Head Sewer Treatment Plant

Wastewater Discharge

Once our wastewater has been chemically cleaned and had all its toxins removed, it’s final journey will be to take It along an outfall pipe.

From there it will be discharged at a designated point, typically into a river or in the case of North Head directly out to sea – approximately 2 km offshore via its submarine pipe.

These outfall pipes are the largest in the series. Some of them are 6m in diameter, the outfall at Ben Buckler measures 8m wide by 10m high, large enough to house a railway locomotive.


Outfall pipe

It takes a large number of highly skilled personnel to keep such a large network of tunnels operating efficiently.

An interesting point of trivia, Sydney Water maintenance engineers use canoes to travel along Bondi’s main sewer to carry out a yearly inspection.

The Role Of Plumbers

So there you are that’s how your water arrives and is later discharged from your home.

But where do I and the guy’s at Dalton Plumbing and the hundreds of other plumbers working in Sydney fit into this story?

Well as mentioned before, there’s a lot of pipework owned by customers on their private land, and if something goes wrong with it it’s their responsibility to get it fixed, so they are going to need a plumber.

Any part in this story is either at the end of the fresh water’s journey or the beginning of the wastewater’s journey.

So that’s some of the ways we plumbers can play a small part in the huge system that utilises vast amounts of manpower and monumental feats of engineering, in order to keep the water flowing to and from our homes each and every day so that we can all lead cleaner and healthier lives.

So next time you turn on the tap spare a moment to think about that.

Anyway, all this chatting has made me quite thirsty, so I think I’ll go and have a cup of tea.