The Hunter River Catchment
The Hunter River drains the largest coastal catchment in New South Wales, covering some 22,000 square kilometres.
The Hunter region supports a range of agricultural activities including wineries, dairying, vegetables, fodder, beef and horse breeding.
Also located in the valley are over 20 of the world's largest coal mines and three power stations, including Australia's largest electricity generator.
Salt occurs naturally in many of the rocks and soils of the Hunter Valley. Some of this salt is leached into groundwater and nearby rivers.
Human activities also impact on river saltiness. During coal mining, salty water collects in mine pits and shafts and has to be pumped out to allow mining operations to continue.
Electricity generation uses large volumes of river water for cooling. As this water evaporates, natural salt is concentrated in the water that remains.
Salinity
Water salinity is estimated by measuring electrical conductivity. The more salty water is, the more it conducts electricity. Electrical conductivity is measured in microsiemens per centimetre (mS/cm). Drinking quality water usually measures between 600EC and 1200EC.
Since the scheme started, river salinity has more consistently been below the salinity target.
Page last updated: 21 February 2008