Sewerage / Sheet 7
The first sewers
Melbourne’s first homes were connected to a sewer in 1897, after a Royal Commission into a public health crisis; until then, household and factory waste ran in open drains to the rivers. Much of what the city built survives, and several pieces are on the Victorian Heritage Register.
History from Melbourne Water, the Victorian Heritage Database and Sydney Water, listed at the foot of this page.
Before the sewers
In early Melbourne, waste from houses and factories ran along open drains beside the streets and into the rivers people drank from, and typhoid spread. Toilets were buckets in backyard closets, emptied weekly by a nightman who carted the waste to market gardens on the city’s edge. The gold rush made Melbourne rich and crowded, and it earned the nickname “Marvellous Smellbourne”.
How Melbourne built it
- 1888A Royal Commission looks for an answer to the health crisis and settles on underground pipes carrying sewage to a treatment farm.
- 1889 to 1891Plans are drawn in 1889, and in 1891 the Melbourne and Metropolitan Board of Works is formed to run water supply and sewerage.
- 1892Construction starts, and the Board begins buying land at Werribee for its low rainfall and suitable soils.
- 1892 to 1894The Main Outfall Sewer is built by seven contractors and 1,300 workers, at a cost of £240,748.
- 1894Work starts at Spotswood on a 25-metre-deep pit, much of it blasted out of basalt, for a pumping station with twelve oval-shaped pump wells.
- 1897The first homes are connected, and the Werribee farm begins treating sewage.
- 1921The first electric pumps arrive at Spotswood; by 1925 electricity is pumping most of the daily flow.
- 1965Spotswood stops pumping in September, replaced by a new station at Brooklyn.
- 1975A second major plant, now the Eastern Treatment Plant, opens at Bangholme.
The plan was the British engineer James Mansergh’s. Every property would have a water closet; sewers growing wider downstream would carry sewage by gravity to the steam pumps at Spotswood; rising mains would lift it to Brooklyn; and the Main Outfall Sewer would carry it 25 kilometres to the farm at Werribee. The Heritage Register’s entry notes that Mansergh chose treatment by broad irrigation, sized for 50 years of growth, at a time when most cities sent raw sewage straight into rivers and the sea.
Treating sewage with paddocks
From 1897 the Werribee farm’s main summer method was land filtration. A paddock was flooded with sewage to about 10 centimetres over a day or two, then left to drain through the soil for several days, with the filtered water running off to Port Phillip Bay. Sheep and cattle grazed the paddock for around two weeks before the next flooding.
Grass filtration took over as the winter method in the 1930s, and the first lagoon was built in 1936. Today modern lagoons treat all the sewage at the site, now the Western Treatment Plant. It was added to the Victorian Heritage Register in 2021.
Geelong’s egg-shaped outfall
Geelong was among the first regional Victorian cities to plan a sewerage system. Its outfall sewer, part of the scheme built in 1912–15 for the Geelong Waterworks and Sewerage Trust, ran from the town to the coast at Black Rock and was made of reinforced concrete pipe in an ovoid shape.
Where it crossed the Barwon River floodplain at Breakwater, the pipe rode on a long reinforced concrete aqueduct designed by the Tasmanian engineers Edward Giles Stone and Ernest J. Siddeley, who set up a factory nearby to cast the pipe sections from 1912. Cracks appeared by 1922. The aqueduct was taken out of service in 1992, when a new main went under the river, but the structure was kept and is on the Victorian Heritage Register.
What you can still see
- Spotswood Pumping Station became the Scienceworks museum in 1992.
- The Main Outfall Sewer has been replaced in use by the Western Trunk Sewer, but much original fabric remains along its easement, unlike the rest of the system, which is out of sight underground.
- The Kororoit Creek aqueduct, part of the outfall sewer, is a five-span brick-arched aqueduct on brick piers, disused but described as in good condition and intact.
Sydney’s northern tunnel
Sydney’s Northern Suburbs Ocean Outfall Sewer was built in stages from 1916 to 1933, mostly tunnelled through rock. It was the city’s third major wastewater system, running along the north side of the Parramatta River as far west as Blacktown and carrying wastewater to the North Head plant at Manly.
It is 26 kilometres long, serves about 1.36 million people and collects around a quarter of Sydney’s wastewater each day. Its concrete lining has worn, and since 2017 Sydney Water has been clearing and restoring it while it stays in use, in places up to 90 metres below the street.