4 - The Snowy Mountains hydro-electric scheme

Summary

LOCATION

The Snowy Mountains area is located in the south-east corner of the State of New South Wales (Figure 4.1). It is the most elevated area of the continent and includes Australia's highest peak Mt Kosciuszko with an elevation of 2228 m. The average annual precipitation for most of the area ranges between 1200 mm to 1600 mm with small areas exceeding 2000 mm (Figure 3.2). Above an elevation of 1400 m, precipitation in winter often falls as snow and extensive areas are covered with a thick mantel. The major rivers of the area are:

• The Snowy River, which originates at an elevation of 1770 m, drains the south-eastern part of the area along its 300 km length, and discharges to Bass Strait at Marlo (south-east of Orbost) in Victoria. One of its major tributaries is the Eucumbene River (see Figure 4.3).

• The Murrumbidgee River, which drains the north-eastern corner of the area. Its major tributary is the Tumut River.

• The River Murray, which has its source in the western part of the region.

The Snowy Mountains Hydro-electric Scheme, which diverted flows from the Snowy and Murrumbidgee rivers is located in the Snowy Mountains area.

HYDROLOGY

The Snowy River has an average annual natural flow of 1177 × 10⁶ m³ at Jindabyne (see Figure 4.3) and 2150 × 10⁶ m³ at its mouth. The Snowy catchment above Jindabyne represents approximately 15 percent of the total area of the catchment, but because of the high precipitation, it contributes approximately 50 percent of the total annual run-off of the catchment.