If you type ‘Lake Pedder’ into Google Maps you’ll see something quite different from the original hand-drawn, illustrative or topographical maps that show the original Lake Pedder pre-inundation.

A million years ago when a glacial outwash blocked the flow of the Serpentine River, Lake Pedder—a unique glacial lake—was formed.

It was nine square kilometres in area with a beach of pink quartz sand three kilometres long and nearly one kilometre wide in summer when the lake’s level was low.

The alignment of the Frankland Range to the south and west acted as the perfect ‘snow-farm fence’, capturing prevailing snows that in turn powered glacial features that carved and sculpted the landscape.

Winston Nickols writes:

“My first trip to Lake Pedder was from the Gordon River Road with three of my workmates from ABC TV in Hobart.

It was a July day and it took us five hours. The track climbed through a pass in the Sentinel Range, (up in the clouds here) then down to Swampy Creek and the plains before a final drag over a gap in The Coronets…..Wow, what a view…..

We made our way along the beach to a crude hut in the sand dunes just beyond Maria Creek. The weather was calm during the day but heavy rain fell throughout the night.

A wonderful time spent in a remarkable place.

Then a very wet trip out and an awkward crossing of swollen Swampy Creek.”

  

An informative map from Nigel Harding The Pedder Portfolio (Jacaranda Wiley 1987) – a book for children on the battle to save Lake Pedder in Tasmania.

Note the numerous creeks flowing into Lake Pedder from the east, the west and the Frankland range to the south, the swampy ground along Maria Creek and the Serpentine River, the extensive areas of sand all around the shores of the lake and the lunettes (crescent shaped dunes) behind the beach.

  

Road from Maydena to Strathgordon in red. The shortest track to Lake Pedder ran south from it through a pass in the Sentinel Range, across Swampy Creek, over the Coronets and down to the lake.

The alternative, earlier route ran from Maydena via Frodshams Pass and to the west of Mount Anne – this is the Old Port Davey Track.

Left bottom track led to Port Davey. At bottom right, junction is Craycrofts Crossing (on the Craycroft River). From it:

• track heading south led to the Eastern Arthurs and Federation Peak
• track heading east led to Geeveston.

Note how Lake Pedder served as a departure point, and a resting place for those walking to the Western Arthurs, the far south west and Mount Anne.

Map produced by and courtesy of Matt Dell.

  

This old contour map illustrates how Lake Pedder was sheltered to the south and south-west by the Frankland Range. Note the numerous creeks flowing north from the Franklands into Pedder and east into the Serpentine River; also the creeks flowing south-west into the Frankland River from the Companion Range which runs parallel to and south-west of the Frankland range. Note also the flat valley floor of the Serpentine in contrast to the rugged peaks surrounding it.

  

Historic sketch map dated 1953, courtesy of Janette Asche.

  

Lake Pedder in relation to the Scotts Peak and Edgar dams. Hydro Tasmania’s 10-year asset management plan 2016 states that of the 204 dams in Hydro Tasmania’s portfolio, three are high risk: Edgar, Scotts Peak and Murchison. Edgar dam, (lower right of map) is high risk because of its immediate proximity to the Lake Edgar fault. The reason why Scotts Peak dam is rated high risk is assumed to be its close proximity (5 km) to the fault.

Map courtesy of Sharples, Chris (ed) Lake Pedder: Values and Restoration. The proceedings of a symposium held on 8th April 1995 at the University of Tasmania, Hobart. Occasional Paper No. 27, Centre for Environmental Studies, University of Tasmania.

  

Lake Pedder Lake Gordon & the Huon-Serpentine Impoundment

This satellite image shows Lake Gordon to the north and east of Strathgordon, the village located near the Gordon dam and hydro-electric power station. The Huon-Serpentine Impoundment (officially known as “Lake Pedder”, colloquially known as “the new Lake Pedder”) lies to the south and east of Strathgordon and has a surface area of 242 sq. km. For a discussion of nomenclature, see the topic A Controversial and Contested Name in the Lake Pedder article in Wikipedia.

Lake Pedder (surface area 10 sq. km.) lies beneath 12 metres of water west-north-west of the largest island in the Huon-Serpentine Impoundment. The devegetated zone visible at the waterline in Lake Gordon indicates that the reservoir is not full. The Huon-Serpentine impoundment does not function as a reservoir; its water level is fixed and there is no devegetated zone. The impoundment traps the water of the Serpentine River (whose source was the original Lake Pedder) flowing to the north west and the Huon River flowing to the south east. These waters are lifted by the impoundment to a height from which their current combined volume of flow drains by gravity into Lake Gordon through the McPartlan Pass Canal. The large volume of water stored in the impoundment serves no purpose other than to lift the current flows of the Serpentine and Huon Rivers to a height from which they can flow into Lake Gordon.

The most common fallacy and piece of misinformation in understanding and debating the Lake Pedder issue is the belief that the Huon-Serpentine Impoundment is a valuable, even indispensable water storage. For example, former Premier Robin Gray speaking as Minister for Energy,(circa 1994): “Conservationists must be aware that Lake Pedder is a crucial storage for the Tasmanian hydro-electric system… the lake is a source of stored energy that Tasmania cannot afford to lose… the bulk of the long term storage capacity is held in just three lakes, Pedder, Gordon and Great Lake… storages have fallen…without the storage in Lake Pedder the situation would be worse” – for more, see Tasmanian Government view, circa 1994. These statements are fallacious. Lake Pedder is NOT a water storage – it is a mechanism to raise and divert the current flows of the Serpentine and Huon Rivers into Lake Gordon. It holds a large volume of water but that water is never used to generate electricity.

This image shows in more detail the devegetated zone at the waterline in Lake Gordon (top centre of image) and the absence of a similar zone in the Huon-Serpentine impoundment (bottom left of image). The image is offered as visual proof that the impoundment does NOT function as a reservoir. As the impoundment is not a reservoir, the power scheme can therefore be re-engineered to restore Lake Pedder and transfer the water that passes through the impoundment to Lake Gordon without significant loss in storage capacity.