The Canning Tunnel is a tunnel that originates just west of

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 ...

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 north–south to the east of the Swan Coastal Plain and Perth, Western Australia. The escarpment extends generally north of Bindoon, to ...

to the western portal trunk main in Soldiers Road about south of the Brookton Highway intersection. It measures . A separate pipeline from Canning Dam remains. The tunnel is more than below ground level at its deepest point.

History

The Canning Tunnel was constructed between 1973 and 1975 to link Canning Dam to Perth's Integrated Water Supply System.State Heritage Office record for "Canning Contour Channel (fmr)"
/ref> It was built to replace the Canning Contour Channel, which was a depression era public works project of the 1940s and constructed in conjunction with the opening of the dam. 110 men were employed in the first year of construction after which the workforce reduced to 60. The tunnel was built at a cost of , equivalent to in , and was officially opened by Desmond Henry O'Neil, the Minister for Works, Water Supplies and Housing, on 17 January 1975. The Canning Contour Channel was maintained and partially operated for two years after the tunnel's opening as a precautionary measure.

References

Tunnels in Western Australia Water supply and sanitation in Western Australia Tunnels completed in 1975 Darling Range {{Australia-struct-stub