The Canning Contour Channel is a series of human-made

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

channels and steel and cast-iron pipelines in the

Darling Scarp The Darling Scarp (), also referred to as the Darling Range or Darling Ranges, is a low escarpment running north–south to the east of the Swan Coastal Plain and Perth, Western Australia. The escarpment extends generally north of Bindoon, to ...

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

constructed between July 1935 and December 1936. The project was a Depression era public works scheme to carry

potable water Drinking water or potable water is water that is safe for ingestion, either when drunk directly in liquid form or consumed indirectly through food preparation. It is often (but not always) supplied through taps, in which case it is also calle ...

from just below

Canning Dam The Canning Dam and reservoir are a major source of fresh water for the city of Perth, Western Australia. The dam is situated on the Darling Scarp and is an impoundment of the Canning River. It is noted for its innovative structural and hydraul ...

through the hills around and above Roleystone and

Kelmscott Kelmscott is a village and civil parish on the River Thames in West Oxfordshire, about east of Lechlade in neighbouring Gloucestershire. Since 2001 it has absorbed Little Faringdon, which had been a separate civil parish. The 2011 Census ...

to a screening,

fluoridation Water fluoridation is the controlled addition of fluoride to public water supplies to reduce tooth decay. Fluoridated water maintains fluoride levels effective for cavity prevention, achieved naturally or through supplementation. In the mou ...

and pumping station near Gosnells by following the natural contours of the Canning Valleyhence it was entirely

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

-fed. Where a tributary valley needed to be crossed, suspended or siphoning pipelines were used. From Gosnells, the water entered the city's pipeline distribution system. The channel supplied drinking water to the metropolitan area of

Perth Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...

from 1940 to 1975, before becoming redundant after the construction of the

Canning Tunnel The Canning Tunnel is a tunnel that originates just west of Canning Dam and runs for approximately through the granite Darling Scarp The Darling Scarp (), also referred to as the Darling Range or Darling Ranges, is a low escarpment running ...

in the mid-1970s. Until the construction of Serpentine Dam in 1961, Canning Dam and the channel were the main sources of water supply for Perth. Large sections of the disused channel and associated infrastructure remain and provide useful bush-walking routes. In 1950 a section of the channel collapsed at Araluen, causing severe water restrictions in Perth for several weeks.

Course

The channel starts at a stilling chamber on the north bank of the

Canning River The Canning River ( or ) is a major tributary of the Swan River in the South West Land Division of Western Australia. It is home to much wildlife including dolphins, pelicans, swans and many other bird species. Source and route With headwate ...

, just below the Canning Dam. After just over , it enters a siphon to cross the Canning River. It then flows alongside McNess Drive down the Canning valley. A siphon is used to cross McNess Drive near the junction with Bristol Road and it also crosses the Canning River to the north bank. The channel flows to the north of Croyden Road into Roleystone to a point above

Brookton Highway Brookton Highway is a long undivided single carriageway highway in Western Australia, running from the southern Perth suburb of Kelmscott, Western Australia, Kelmscott, through Westdale, to the southern Wheatbelt (Western Australia), Wheatb ...

, which is crossed with a siphon. The channel continues west, then north-west to cross Peet Road between Knuckey Drive and Beales Crescent. It follows Contour Road to the west, and uses a siphon to cross Slab Gully. Further channels and siphons continue west to cross Canning Mills Road near Martin Street, and then north, crossing Turner Road on its way to its destination in Martin on Mills Road.

Construction

It was built by the

Public Works Department This list indicates government departments in various countries dedicated to public works or infrastructure. See also * Public works * Ministry or Board of Public Works, the imperial Chinese ministry overseeing public projects from the Tang ...

for the Metropolitan Water Supply and was designed under the direction of several prominent engineers of the era:

Russell Dumas Sir Russell John Dumas KBE, CMG (17 January 1887 – 10 August 1975) was a public servant and engineer who led several large works projects in Western Australia. Early life Dumas was born in Mount Barker, South Australia second of five child ...

, E. W. Tindale, Victor Munt and Don Munro. Engineers E. H. Oldham and J. W. Allen supervised the construction project. This was the same team which had overseen the design and construction of the Canning Dam and which was completed in 1940. Construction commenced in June 1935 and was completed in January 1937. The project was a considerable technical achievement which required a high degree of manual labour due to the hilly terrain which made it difficult to access with mechanical equipment. Most of the construction was carried out by unemployed men on relief work. Prior to completion, water from the partially filled Canning Dam and the pipehead dam below was conveyed to Perth through a pipeline to Kelmscott and a pipeline from there to the storage reservoir at Mount Eliza in Kings Park. Once the dam wall was completed and the dam had filled, the pipeline was discontinued. A pipeline carried the water from Gosnells to Cannington where it was diverted to

Fremantle Fremantle () () is a port city in Western Australia located at the mouth of the Swan River (Western Australia), Swan River in the metropolitan area of Perth, the state capital. Fremantle Harbour serves as the port of Perth. The Western Australi ...

and King's Park. Three hundred and twenty men were laid off when construction was completed and the total cost of the project was

£A The pound (Currency symbol, sign: £, £A for distinction) was the currency of Australia from 1910 until 14 February 1966, when it was replaced by the Australian dollar. Like other £sd currencies, it was subdivided into 20 Shilling (Australian ...

125,000, equivalent to in , almost 20% less than the estimated

155,000. The typical profile of the channel is a culvert approximately wide at its base with raking sides at 45 degrees banking up to the natural ground level where the top of the channel is approximately wide with a depth of approximately . The channel was cut from the natural ground or rock and then lined with concrete made from Western Australian made

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...

mixed with locally sourced oolithic

laterite Laterite is a soil type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolo ...

aggregate. Pipework across shallow gullies was typically

cast iron Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its car ...

of varying diameters, joined by

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

seals. Deeper gullies were crossed using

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

pipes joined by welding. A separate contour channel ran north from Canning Dam to allow

Mundaring Weir Mundaring Weir is a concrete gravity dam (and historically the adjoining locality) located from Perth, Western Australia in the Darling Scarp. The dam and reservoir form the boundary between the suburbs of Reservoir and Sawyers Valley. The ...

to be replenished with water from Canning Dam. This is now inaccessible as it is within the dam's water catchment areas. Another channel ran from Kangaroo Gully near Karragullen into Canning Dam to augment the water catchment.

References

{{subject bar , auto=y , portal1=Western Australia , portal2=Modern history Water supply and sanitation in Western Australia Canning River (Western Australia) Aqueducts in Australia State Register of Heritage Places in the City of Armadale State Register of Heritage Places in the City of Gosnells Darling Range Transport buildings and structures in Western Australia