What is salinity?

Salinity is the discharge of high levels of salt to the environment. Rain naturally contains small amounts of salt, which is harmless to the environment, but plants generally exclude this small amount of salt when they take up water with their roots. This leaves salt to accumulate in the soil, below the root zone of plants.
Periods of higher rainfall, or decreasing the amount of water plants are using by removing native vegetation for example, can mobilise this salt and allow it to pass into the groundwater, which, in turn, can allow it to flow into rivers and streams or into low lying areas of land.

Why is salt a problem?

Elevated levels of salt will stress plants and animals that have not adapted to it. In rivers, streams, and wetlands; fish, invertebrates, and plants will all be affected and some species may not be able to survive as salt levels increase. Elevated salt levels on land stress and kill trees and affects crops and pasture. Salinity can also cause infrastructure problems, reducing the service life of roads and buildings, which increases maintenance costs.

Salinity in Wimmera waterways

Across the region the water table does not need to rise far to put Wimmera waterways at risk from salinity. Deep pools in the Wimmera River and wetlands in the Natimuk Douglas Depression have always been impacted by salinity. However, land clearing has meant that groundwater levels have risen further, affecting more locations on the Wimmera River as well as other waterways such as wetlands near Edenhope.

What is Wimmera CMA doing about Salinity in the Wimmera?

Whilst issues around salinity will affect parts of the region on an ongoing basis, Wimmera CMA has undertaken revegetation to try to curb the rise of groundwater levels in some sub-catchments. Increasing stream flows helps improve water quality, although this will only address the symptoms of salinity rather than the causes. Apart from ongoing monitoring of groundwater levels, there have been a number of investigations into other actions such as groundwater pumping and saline pool aeration to find other feasible actions that, reduce the impact of salinity in priority areas.

We acknowledge the Traditional Owners and other Aboriginal and Torres Strait Islander Peoples across the region and pay respect to Elders past, present and emerging.

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