Canning Contour Channel, Water channel in the Darling Scarp, City of Armadale, Western Australia

The Canning Contour Channel is a water distribution system spanning about 16 kilometers through the Darling Scarp using concrete channels and metal pipes. It flows by gravity from Canning Dam through Roleystone and Kelmscott, ending in Gosnells.

The system was built between 1935 and 1936 during the Depression, employing local workers to ensure Perth's water supply. This project represented a major effort to develop the region's water resources during an economically difficult period.

The channel's name comes from the Canning River and its contour-following route. Most of it was dug by unemployed men on relief work during the Depression, and 320 were laid off when it was finished. Walkers today follow the concrete culvert, about 1.5 m wide at its base, past siphons that cross roads and gullies.

The channel runs from a stilling chamber below Canning Dam through Roleystone and Kelmscott to Martin on Mills Road, crossing roads and gullies by siphon. Disused sections serve as bush-walking routes, but the terrain is hilly and access is uneven. A separate contour channel north of the dam lies inside the catchment and cannot be visited.

A section at Araluen collapsed in 1950, revealing how much strain the infrastructure faced from the terrain. This event shows the challenges that early water systems had to overcome in this region.