Qualla: Serpentine Dam

Serpentine Dam: Introduction

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Arthur Taksin, CC BY 4.0. In 2011, water supplies across Perth and the South West reached critically low levels after nearly a year without significant rain. It was the kind of headline that forced a sprawling city of two million to confront an uncomfortable truth: in a drying climate, every reservoir matters. Serpentine Dam, completed in 1961 and tucked into the jarrah-clad Darling Plateau about 12 kilometres south of Jarrahdale, is one of the reservoirs that matters most. Supplying an average of 39 billion litres per year - with another 2 billion from natural inflows to its companion, the Serpentine Pipehead Dam - it forms a critical node in Western Australia's Integrated Water Supply System, the largest such scheme managed by the Water Corporation.

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Image: Arthur Taksin | CC BY 4.0

Serpentine Dam: Engineered for a Thirsty Coast

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Gnangarra, CC BY 2.5 au. The dam sits within a catchment of 664 square kilometres on the Darling Plateau, where the reservoir surface rests at 217 metres above sea level and the catchment's highest point, Mount Cuthbert, rises to 582 metres on the eastern boundary. The dam wall stands 55 metres tall at i...

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Image: Gnangarra | CC BY 2.5 au

Serpentine Dam: The Bauxite Bargain

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Museedesgueulesrouges, CC BY-SA 3.0. Beneath the jarrah canopy that feeds the catchment lies bauxite ore, and Alcoa has mined it here since 1963. The process is brutal on the landscape: forest clearing, soil stripping in two layers, blasting of lateritic duricrust, and removal of the friable bauxite underneath. The ...

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Image: Museedesgueulesrouges | CC BY-SA 3.0

Serpentine Dam: Guarding the Water

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit User:Orderinchaos, CC BY-SA 3.0. Pathogens are a persistent threat to any open catchment, and at Serpentine the risks arrive from unexpected directions. Off-road driving on unauthorised tracks accelerates erosion, lifting soil particles into waterways where pathogens adsorb to them and resist disinfection more e...

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Image: User:Orderinchaos | CC BY-SA 3.0

Serpentine Dam: Trails Through the Catchment

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit JarrahTree, CC BY 2.5 au. Despite its role as a protected water source, the Serpentine catchment is far from off-limits. The Bibbulmun Track, one of the world's great long-distance walking trails, passes through the catchment roughly 25 kilometres upstream of the dam, linking the Monadnocks and White Hors...

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Image: JarrahTree | CC BY 2.5 au

Serpentine Dam: A Drier Future

Fri, 27 Mar 2026 00:00:00 GMT

Photo credit Arthur Taksin, CC BY 4.0. Perth's climate is shifting. Rainfall has declined measurably since the 1970s, and the prospect of consecutively dry years is no longer hypothetical. The Serpentine Dam is intended to continue supplying the metropolitan area, but planners acknowledge that the existing IWSS dams a...

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Image: Arthur Taksin | CC BY 4.0