Lake Albert salinity drops

Drier times: Lake Albert's water became extraordinarily salty during the drought of 2009-10, but its salinity has since returned to a useful level. Photo: File.
Drier times: Lake Albert's water became extraordinarily salty during the drought of 2009-10, but its salinity has since returned to a useful level. Photo: File.

Water level cycling and environmental water from interstate can be credited for a reduction in the salinity of Lake Albert, claims state Water and River Murray Minster Ian Hunter.

Salinity levels in the lake have fallen below pre-drought levels of about 1500 EC units, a measure of saltiness, from highs of more than 20,000 units at two monitoring sites in 2010.

The lake's salinity fell sharply away from that peak to about 7000 units by the end of 2010, and has continued to fall at a reasonably consistent rate ever since.

The Environment Protection Authority classifies fresh water as being less than 1000 EC units.

The Department of Environment, Water and Natural Resources (DEWNR) began cycling the water in the lake, artificially raising and lowering its level over time to encourage more water to circulate, in 2014.

Mr Hunter said the removal of salt from the lake was magnificent to see.

"The reduction in water quality has improved water quality for the environment, economic and social uses," he said.

"Salinity management is one of the most significant environmental challenges facing the Murray-Darling Basin.

"If not managed appropriately, it has serious implications for water quality, plant growth, biodiversity, land productivity and the supply of water for critical human needs."

Meningie district residents rejected cycling as a possible solution at a public meeting in 2014, saying a pipeline linking the lake's southern end to the Coorong would be more effective.

But DEWNR's director of River Murray operations accurately predicted cycling would bring the lake's salinity level below 2000 EC units "within about two years".

A Regional Development Australia study earlier in 2014 had suggested make Lake Albert's water less salty would generate more than $30 million worth of economic benefits to the communities around its edge.

Feedback wanted

The state government is currently seeking feedback on changes to its River Murray salinity zoning policy, which has until now restricted how much water can be used to irrigate any given parcel of land.

Two options have been proposed.

The first, preferred by the government, would allow irrigators to gain approval at a site - possibly at a higher level than in the past, which would allow for thirstier crops - for a fixed, 30-year period.

The second option would remove limits on the volume of water to be used at a site, and instead bring in limits on the area to be irrigated.

The second policy option would take more than 12 months to put into effect because various legal documents would need to be amended.