• Me with rainwater collected at Sydney’s Sustainable House
by
Lucy Bamford, intern with Sydney’s Sustainable House
In January, a month ago when I arrived in Sydney from the United States, I had never thought about how using water for my daily life can hurt the environment that keeps me alive.
The further water got away down the drain, the further my thoughts about the impact of much water I was using or wasting – beyond the cost of a water bill – got from me.
How water moves
I hadn’t considered the amount of energy that went into bringing my water out of the tap until Michael asked me to pick up a bucket of rainwater being collected in the back of the Sustainable House.
In that moment, holding around 4kg of rainwater, I was suddenly aware of the great strength and energy Earth uses to provide clean water for us; the bucket was heavy. I tried to imagine the billions of tonnes of water that rains down on us, and the amount of energy it takes to move that and the 4kg into the air, clean it, and drop it back down as rainwater. And to do that lifting and rain-making causing no pollution, using just Earth’s natural water-lifting and rain making powers – how amazed I was to see and feel this with the bucket in my hand.
I found that the average Australian uses 274 litres of water each 365 days of thee year. That figure does not include the water needed to grow the food I’m eating. and then think about that water usage on a global scale. The amount of energy it takes daily for Earth to move, clean, and rain down that much water across the globe is almost incomprehensible to my mind. And the Earth does this effortlessly.
• How Earth lifts and cycles water 
Earth naturally cycles water on its own, cleanly.
I began to compare how much energy it take for our city water systems to clean and transport water to our taps? What are the environmental impacts of pumping this water through thousands of kilometres of pipes – Sydney’s water travels through 23,000 k of pipes, for example?
As a new user of Sydney Water since coming here from the US, I wanted to find an answer to these questions using numbers that apply to me. I spent some time looking for pollution figures on their website, and it wasn’t easy. By turning on taps to shower, wash, cook I was using town water pumped using almost entirely coal fired energy. What was my climate pollution by using town water?
Although Sydney water provides figures in their annual environmental performance reports, the figures are not easy for me to understand as they are given in yearly tonnes for greenhouse gas emissions and for the entire Sydney water system.
I found that Sydney Water is known for providing information about its pollution that is hard to understand. For example, a review of Sydney Water Corporation’s Environmental and pollution indicators done by independent auditor showed that the data that Sydney Water reports is “not readily able to be interpreted by Sydney Water customers” (GHD 2004).
Sydney Water is required to provide data on a wide array of environmental factors and impacts under the legislation creating it, the Sydney Water Act of 1994, and report these findings annually but there is no specific guidance on the way that they must display them (GHD 2004). This means we as readers have to take the time and effort to understand the meaning behind the numbers Sydney Water is throwing at us, which to me, an average water user, is hard to do.
Some of my pollution from my town water use
To better understand the carbon impact of water and wastewater usage for myself and other Sydney Water users, I’ve taken time to calculate the pollution from of my town water use in simple, easy-to-understand words.
Using the numbers provided in its annual report, I calculate that the average person on Sydney Water pollutes 0.169 grams of CO2 emissions for every litre of water they use.
Based on Sydney’s population (over 8.5 million) and Sydney Water’s yearly carbon pollution figures I’d pollute 20 kg of emissions, as does every other person here each year. That’s pollution equal to the pollution of driving an average car for around 100 km.
Although this may not seem like a lot, factor in the whole yearly emissions for all of Sydney Water users, which is 105,468 tonnes (105,468,000 kg) of emissions per year. That is equal to the pollution from driving 526 million km, over 13,000 times around Earth, in a single year, based on Environmental Protection Agency predictions. Factor in the wastewater treatment as well because the sewage is also pumped through thousands of kilometres of pipes, and these figures double.
But wait, there’s more . . .
Turning the tap on and flushing the toilet aren’t the only ways I waste water every day.
One of the main water losses comes from my wasted food. If food waste was a country, it would be the third highest polluter in all the world. The image below highlights how much water goes into producing food items that are consumed every day and thus when we waste them, we lose the water used in their production, transport, and preparation for eating. Various calculations of the pollution caused by waste food range from a low of 1.5 kg climate pollution to 23 kg of climate pollution for each kg of food wste. Taking the high estimate 3kg of my food waste creates 23kg of carbon pollution and a waste of the water used to produce the food.
• A thousand litres of water for a typical breakfast – the chicken for example, doesn’t drink 80 litres to produce that egg – that 80 litres counts the water to grow crops to feed the chicken, wash the egg and all that’s needed to create it Image from “Sustainable Food” book by Michael Mobbs
What if we change how we use water in cities, such as has been done for the last 28 years in Michael’s Sustainable House in Chippendale beside the city central business district, where rainwater is collected and reused in the home without a connection to Sydney Water’s pipes?
Rainwater in Sydney is wasted. As you can see in the graph below, more rainwater falls and is wasted than is imported in Chippendale
• This graph by Mat Faint highlights how more rainfall falls in the Chippendale area than is imported through Sydney water, further highlighting how rainwater is an underused resource. Refer to this blog to learn how money for the state drives this system.
The large amount of energy it takes to clean and transport water from outside the city is partly why the climate pollution by Sydney Water is so high since the water out of the tap that I am using is pumped through the 22,804 kilometres of Sydney Water pipes. The graph below shows the potential impact of using rainwater, as has done at Sustainable House, compared to the emissions of an average Sydney Water property using the most recent data.
• Climate pollution based on Sydney Water Supply Annual Report, measured in kg CO2 equivalents. 
I eat three times a day so I get three chances daily to reduce my waste of water in that food.
I can “recapture” the water in my waste food by composting it, and that’s what I’m doing here in Sydney. I’m doing this using a Coolseat composting garden. Designed by Michael Mobbs, Coolseats are both composters and garden beds that I can put my food waste into along with carbon-waste such as cardboard, toilet rolls, paper towels or tissues. The carbon combines with the food waste and water in it to make compost that I then put in gardens such as pot plants at home or in the community gardens in the footpaths of Chippendale streets. Coolseats also save water through a water storage bed under the plants that feeds water to the roots of the plants above in the garden bed; these are called “wicking cells”..
• This diagram shows the Coolseat garden bed and dimensions. Click on this link to learn more. 
The best thing for me about using a Coolseat for composting, gardening and as a seat is that it’s simple and I can immediately start saving food waste and water. Check out this video I made about how I compost using Coolseats!
• Here is the Coolseat I used in a Chippendale footpath garden and put my waste into; the food waste is decomposing and offsetting emissions inside!
In just those five days in which my three roommates and I composted, we produced around 3kg of food and other carbon waste. Using the Coolseats calculator, which is a free tool available to use online, I was able to see that we avoided 6 kg of CO-2-equvialent emissions avoided and was able to see graphs that highlight the impact of composting over wasting. I can see now how important it is for the ‘waste’ carbon (paper, cardboard, etc) to be redirected into the soil and not being wasted in the total waste values.
• This graph highlights how over five days, my roommates and I redirected more carbon into the soil and thus were able to cut our carbon emissions and save water. 
How Overuse Affects Us
I now see problems from wasting water and food playing out, and which I’m facing, in and around Sydney.
International media has covered the mysterious black or coal-looking balls that have started to appear on some of Sydney’s most famous beaches. Though some people have speculated that these have come from coal or oil or other various substances, according to the Guardian – a newspaper – they have formed as a byproduct from Sydney’s offshore wastewater pipes which contain a large amount of human waste and by-products such as oil, grease, fats.
I could not imagine the beautiful Coogee Beach in Sydney, that I just visited for the first time this past week, potentially full of these black balls of human matter that have caused many Sydney beaches to be shut down.
• Map of the beaches affected by these mystery balls from the nearby wastewater ocean outfalls. Source-Guardian 2025.
• People enjoying the Giles baths at Coogee Beach in January 2025 when I visited for the first time.
By using town water I can’t flush or wash away my carbon pollution.
But by composting my wasted food I can save the water in it and prevent the climate pollution from it had it gone to landfill.
Going outside and exploring has been one of my favorite parts about living in Sydney. I want people to experience the same joy that I feel living in this city every day by having a world where the natural beauty is preserved and where we can learn to further appreciate Earth and the rainwater that she and her clean energy provides us with to grow our food and live.
by
Lucy Bamford, intern with Sustainable House and Coolseats
Sources (hyperlinked throughout and also listed here:
https://www.sydneywater.com.au/content/dam/sydneywater/documents/annual-environment-report.pdf
https://www.sydneywater.com.au/water-the-environment/how-we-manage-sydneys-water/water-network.html
https://outlook.office.com/98d740e4-f283-422e-9dc1-555c6a51a792
https://www.sustainablehouse.com.au/products/sustainable-food-book