King river at entrance to Macquarie Harbour - the West Coast Wilderness Railway line passes from the right of this picture to enter the King River Valley at the left of photo. Delta of eroded material is typical at this location. Hell's Gates is at top of picture (out of view) and Strahan is to the right off photo. Photo hazy due to bushfires of January 2003.
The upper section of the river lies in a glaciated valley, with glacier scouring scars high up on the upper parts of the mountains of the West Coast Range. Also small glacial lakes occur on and north of Mount Sedgwick. Lake Beatrice for instance lies on the eastern slope of Mount Sedgwick. The upper portion of the King River valley was first surveyed for damming in 1917 by the Mount Lyell Mining and Railway Company.
King River Power Development Scheme
The river is impounded by the Crotty Dam to form Lake Burbury, covering 54 square kilometres (21 sq mi) over the former valley and named after the first Australian born Governor of Tasmania, Stanley Burbury. Water drawn from the lake is used to supply the conventionalhydroelectricJohn Butters Power Station, operated by Hydro Tasmania. Below the dam wall, the river flows through a narrow channel as it flows west towards Teepookana, in the last 10 kilometres (6.2 mi) of the river, where extensive silting from the mine tailings that have been carried down from Queenstown, has created such a resource that at least one mining company has in the past proposed the mining of the deposits at the edge of the river, as well as the delta formed out into Macquarie Harbour due to the amount of economically viable materials in the silt.
The small timber mill community adjacent to the old alignment of the Lyell Highway was submerged, as was a significant portion of the old railway alignment of the North Mount Lyell Railway between Linda and Pillinger. The site of the townsite of Crotty, and the smelters of Crotty were also submerged.
The King River was considered to be Australia's most polluted river.[2] Mining started in the 1880s, with the Queen River, a major tributary of the King River, being used for waste water disposal from the Mt Lyell copper mine.
Between 1922 and 1995 low grade ore was concentrated on site and the tailings (ore-washing residue) dumped in the river also.[3]
About 1.5 million tonnes of sulfidic tailings entered the river system each year up to 1995, along with huge volumes of acidic, metal-rich water flowing from the workings. This 'acid mine drainage' is derived from water leaching through the exposed and oxidised sulfide rocks. When it was in operation, the fumes from the ore smelter produced acid rain which also leached minerals from the bare Queenstown hills.[4]
In 1992 the King River was dammed above the confluence with the Queen River to generate hydroelectric power at the Crotty Dam. This changed the flow regime in the King River, and affected the way tailings were transported through the river system. The tailings in the river greatly affect the water quality.[5]
About 100 million tonnes of tailings have been deposited on the banks and bed of the King River and in a delta at the mouth of the river where it enters Macquarie Harbour.[6]
Since the closure of the mine in late 1995, and the construction of a tailings dam by the new operators, tailings no longer enter the river system. However, acid water continues to enter the river due to mine dewatering and run-off from the waste rock dumps. Without the buffering previously provided by the alkaline tailings, the acidity in the Queen and King rivers has increased, and dissolved metal concentrations have greatly increased-to levels highly toxic to aquatic life.
Abt Railway route
The north bank (except for the Teepookana to Quarter Mile Bridge section which was on the south bank) of the lower portion of the King River valley was the route for the old "Abt" rack railway to Queenstown. In 1962 the original builder and owner, the Mount Lyell Mining and Railway Company closed and removed the line. This has been since restored in early 2002 for tourism purposes. The new line follows exactly the same route and is known as the West Coast Wilderness Railway.[7]
^Davies, Peter Eric; Mitchell, Nicki; Barmuta, L. A. (Leon Alexander); Tasmania. Department of Environment and Land Management; Supervising Scientist for the Alligator Rivers Region (Australia) (1996), Mount Lyell remediation : the impact of historical mining operations at Mount Lyell on the water quality and biological health of the King and Queen River catchments, western Tasmania, Supervising Scientist, ISBN978-0-642-24317-1
^Tong, G. D; Williamson, B; Supervising Scientist for the Alligator Rivers Region (Australia); Tasmania. Department of Environment and Land Management; Mount Lyell Remediation Research and Demonstration Program (1998), "Mount Lyell remediation : modelling of the hydrodynamics and chemistry of Macquarie Harbour, western Tasmania", Supervising Scientist Report, Supervising Scientist (published 1988), ISBN978-0-642-24339-3, ISSN1325-1554
^Locher, Helen; Supervising Scientist for the Alligator Rivers Region (Australia); Tasmania. Department of Environment and Land Management (1997), "Mount Lyell remediation : sediment transport in the King River, Tasmania", Supervising Scientist Report, Supervising Scientist, ISBN978-0-642-24320-1, ISSN1325-1554
^Mount Lyell Remediation Research and Demonstration Program; Taylor, Jeff R; Tasmania. Department of Environment and Land Management (1996), Mount Lyell remediation : characterisation and impact assessment of mine tailings in the King River system and delta, Western Tasmania, Supervising Scientist, ISBN978-0-642-24304-1
^Rae, Lou (2001). The Abt Railway and Railways of the Lyell region. Sandy Bay: Lou Rae. ISBN0-9592098-7-5.
Sources
Crawford, Patsy (2000). King: Story of a River. Montpelier Press. ISBN1-876597-02-X.
