Gordon Dam: Tasmania's Largest Dam in the Wild Southwest

**Gordon Dam** on the Gordon River in the southwest wilderness of Tasmania, Australia, is the tallest dam in Australia — a **140-meter** double-curvature concrete arch dam completed in **1974**. With an installed capacity of **432 MW**, it generates approximately one-third of Tasmania's electricity from one of the most pristine and remote natural environments in which any major dam has been built.

Introduction

The dam is located within the **Tasmanian Wilderness World Heritage Area**, a vast tract of temperate rainforest, button grass plains, and wild rivers that is one of the last great wilderness areas in the temperate zone. The controversy surrounding a proposed dam on the nearby Franklin River in the 1980s — which was ultimately blocked by the Australian High Court — became a foundational moment in Australia's environmental and conservation movement.

Engineering & Structure

• Type: Double-curvature arch dam
• Height: 140 meters (Australia's tallest)
• Crest Length: 198 meters
• Reservoir: Lake Gordon (272 km²)

Gordon Dam's arch spans just 198 meters across the narrow Gordon River gorge — one of the shortest crest lengths of any major arch dam in the world relative to its height. The dam's double curvature transfers the load into solid Precambrian quartzite on both sides of the gorge. The thin arch contains approximately 250,000 cubic meters of concrete.

The Gordon Power Station, located underground, houses three 144 MW Francis turbines. The dam operates as a peaking station, generating power during high-demand periods and storing water at other times. A smaller dam downstream on the Gordon River (the Gordon Dam Saddle Dam) completes the reservoir containment.

Geographic Setting

• River: Gordon River
• Location: Southwest Tasmania, Australia
• Coordinates: 42.76°S, 145.97°E
• Lake Gordon Area: 272 km²

The Gordon River flows through the heart of Tasmania's southwest wilderness, one of the most ancient and pristine temperate ecosystems on Earth. The surrounding landscape is a mosaic of Gondwanan temperate rainforest (Nothofagus beech, Huon pine, myrtle), button grass moorland, and alpine heath on the higher peaks. The region receives over 2,500 millimeters of rainfall annually, fed by the westerly winds of the Roaring Forties.

Lake Gordon, the reservoir, is Tasmania's largest lake and Australia's largest inland freshwater body by volume (12.45 km³). It fills a complex system of valleys in the deeply dissected quartzite terrain. The surrounding wilderness contains some of the oldest trees in the world — Huon pines up to 3,000 years old grow along the reservoir's margins and the wild rivers upstream.

Hydroelectric Power

• Installed Capacity: 432 MW
• Annual Output: ~1.4 TWh
• Turbines: 3 × 144 MW Francis turbines
• State Significance: ~33% of Tasmania's electricity

Gordon Dam's 432 MW capacity generates approximately one-third of Tasmania's electricity, making it the most important single station in the island state's hydroelectric system. Tasmania generates virtually all its electricity from hydropower — one of the few jurisdictions in the world to do so — with Gordon Dam as the system's largest reservoir and generating station.

The dam's output is supplemented by Basslink, a 370-kilometer undersea cable connecting Tasmania to the Australian mainland grid. This interconnection allows Tasmania to export surplus hydroelectric power and import electricity during drought years when reservoir levels drop. The cable was energized in 2006 and has fundamentally changed Tasmania's energy economics.

Environmental & Social Impact

• World Heritage Area: Dam lies within Tasmanian Wilderness World Heritage Area
• Franklin River: Proposed downstream dam blocked in 1983 — landmark conservation victory
• Ancient Forests: Huon pines up to 3,000 years old in the surrounding wilderness

Gordon Dam was built before the surrounding area received World Heritage listing in 1982. The dam and Lake Gordon are now within the World Heritage boundary, creating an unusual situation where major hydroelectric infrastructure operates inside one of the world's most celebrated wilderness areas. Any new dam construction in the area would be effectively impossible under current protections.

The proposed Franklin Dam — which would have built a second dam downstream on the Gordon River, flooding the wild Franklin River — became the most famous environmental battle in Australian history. The "No Dams" campaign mobilized thousands of protesters, including over 1,200 who were arrested in a blockade of the dam site. In 1983, the Australian High Court ruled that the federal government could override Tasmania's construction plans to protect the World Heritage area — a landmark decision that established the primacy of environmental protection in Australian constitutional law.

Key Facts

• Gordon Dam is Australia's tallest dam at 140 meters.
• Lake Gordon is Australia's largest freshwater body by volume (12.45 km³).
• The dam generates approximately one-third of Tasmania's electricity.
• The successful campaign to save the nearby Franklin River was a landmark in global conservation.
• The dam lies within the Tasmanian Wilderness World Heritage Area.

Fun Facts

• Gordon Dam's near-vertical downstream face has made it one of Australia's most popular commercial abseiling sites — thrill-seekers rappel 140 meters down the concrete wall.
• The Huon pine trees in the surrounding wilderness are among the slowest-growing and longest-lived organisms on Earth, with some clonal stands estimated to be over 10,000 years old.
• Tasmania generates virtually 100% of its electricity from renewable sources, primarily hydropower — one of only a handful of jurisdictions in the world to achieve this.

Final Thoughts

Gordon Dam is a powerful piece of engineering in one of the last great wilderness areas on Earth. Its electricity sustains Tasmania's economy, while the nearby Franklin River campaign it helped inspire became a defining moment in global conservation — proving that wild rivers, once dammed, can never be restored, but that undammed rivers can be saved.