In 1997, the Billabong Creek catchment was identified as having high salt loads in its upper reaches that would progressively increase salt loads and concentrations in the creek over the next 50 years.
The potential impact would be to increase the salinity levels in both the Billabong Creek and in the Murray River. The end result of this would be to increase electrical conductivity by 3.9 EC units (a measure of salinity concentration) at Morgan, South Australia – the point of measurement for the Murray-Darling Basin Salinity Strategy.
Where is Billabong Creek?
Billabong Creek is the longest creek in the world and is located in southern NSW. The creek rises east of Holbrook and flows to the west for about 320 kilometres before entering the Edward River at Moulamein.
The salt interception scheme is located adjacent to Billabong Creek at Morgan's Lookout immediately north of Walla Walla, about 50 kilometres north of Albury.
How does the scheme work?
The Billabong Creek Salt Interception Scheme consists of a bore that pumps freshwater (less than 930 EC) from a deep aquifer, about 80 metres below the ground, directly into the creek.
Up to 1,500 megalitres of groundwater per year is pumped when the natural flow in the creek is low. This reduces the upward pressure of the deep aquifer that is forcing saline water (about 5,000 EC) from the shallow aquifer into the creek.
Freshwater from the deep aquifer is also made available to local farmers from a standing pipe on the site.
The scheme prevents about 3,000 tonnes of salt each year from entering Billabong Creek and the Murray River.
An additional component of the scheme is the establishment of a wildlife corridor that connects the Billabong Creek at the site of the scheme with Gum Swamp about one kilometre to the east. Both of these areas have high conservation values.
Why is there a problem?
Saline water in the shallow groundwater aquifer flows into the Billabong Creek along a two kilometre stretch near Morgan's Lookout, where the creek intersects with the shallow aquifer.
The palaeochannel, or ancient channel, that contains the deep freshwater aquifer is constricted by the geology that pushes it upward, forcing the saline water in the shallow aquifer into the creek.
What will the scheme achieve?
The Billabong Salt Interception Scheme will lower the salt load in the creek by 3,000 tonnes per year which, together with the wildlife corridor, will provide significant water quality and environmental benefits.
The scheme is estimated to reduce the salinity at Morgan, South Australia by 0.1 EC.
Good quality water is pumped into Billabong Creek, offsetting the impacts of diversions and water used for stock and domestic purposes upstream. This additional water benefits the ecology of the creek and provides water to downstream users who rely on the creek for stock, domestic and commercial supplies.
The region's biodiversity is enhanced by the establishment of a corridor of native vegetation. The maintenance of native vegetation and protection of the region's biodiversity has been identified as one of the key natural resource issues to be addressed within the Murray catchment.
The salt interception scheme is situated between the Walla Swamp and the Billabong Creek, both of which are important biodiversity 'hotspots' within the Murray catchment.
The scheme also provides a major socio-economic benefit to the region.
Who operates the scheme?
An agreement has been reached between the NSW Government through the NSW Office of Water (and the former Department of Environment, Climate Change and Water), and the Norske Skog Paper Mill at Albury. The Billabong Creek Green Offsets Project will allow Norske Skog to discharge a limited volume of moderately low strength saline process water into the Murray River, in return for funding the operation and maintenance of the Billabong Creek Salt Interception Scheme.
This joint initiative allows Norske Skog to maintain and develop its current operation, injecting over $100 million each year into the local economy, whilst maintaining a 0.1 EC benefit at Morgan. This allows for the creation and maintenance of jobs in a rural economy.
Overall, reduced salinity levels in the Murray River are critical for the environment and downstream water users as far as South Australia.
Billabong Creek Green Offsets Project – Frequently asked questions (PDF271 KB)
Local, regional and basin wide benefits at a glance
- Enhanced vegetation and biodiversity with re-established corridor between Morgan's Lookout and Gum Swamp
- Improved water quality and the provision of stock and domestic water for users in the Billabong Creek.
- Increased flows in the Billabong Creek
- Secures Norske Skog's operations
- Increased regional employment opportunities.
- Reduced overall salinity levels in the Murray River as measured at Morgan, South Australia.