Farmers in the Barwon region are currently experiencing drought, which comes with many challenges including increased salinity.
Salinity is the measured concentration of salts in soil and water. When salt levels become too high, this can negatively impact the agricultural industry.
Barwon region farmers are being impacted by high salinity levels being listed as an impact of the drought by stakeholders in the Barwon Drought Reliance Plan . Despite this there has been no recent monitoring of salinity levels across the region.
Where does the salt come from?
There are three different ways in which salt gets into water. Rain in which salt from the sea is carried inland by strong winds and falls in rain. Through rocks as they contain salt and they weather over time and the salts are realised. Lastly, the retreating of seas over 10 million years ago which left sentiment that contained large quantities of salt.
These are instances of primary salinity, Water quality Australia defines as salt that naturally occurs over thousands of years through rain interacting with geological features.
There is also secondary salinity that is caused by humans by land use in which the land produces more salt or causes primary salinity to rise to the surface.
How dose salinity impact farmers?
Drought increases salinity due to less water being available meaning there is less water for the salt to dilute in.
High salinity levels have a negative impact on crop health, particularly crops that are not salt tolerant. As salt accumulates in the soil, it restricts plant growth, reduces yields, and can ultimately lead to crop failure.
Pasturelands are also suffering, due to excess salt in soil which negatively impacts the soils health and makes it more prone to erosion.
There is a significant economic toll on farmers who are struggling with salinity. Many farmers are needing to invest in additional water treatment to remove salt from irrigation supplies, as saline does not only impact crops but is also unsafe for livestock to drink. High salinity also accelerates the decay on agricultural infrastructure, leading to more frequent maintenance and replacement costs and reduction in productivity can result in loss of income.
History of salinity in Barwon region and data collection
Salinity in the Barwon region has been an issue for decades. It was formally recognised as a threat to agriculture in the region, following the first statewide survey by the soil conservation authority in 1950.
The millennium drought saw 10 of the regions 28 lakes experience increase in lake salinity due to increased evaporation according to the Barwon Drought Reliance Plan.
Futher data and research was conducted throughout the 20th century and up until the early two thousands.
Even though salinity is still an issue facing the Barwon region there has not been up to date monitoring of salinity levels in the region.
The most recent data available online of salinity levels in the Barwon region is from 2008 in the Surf Coast Salinity Management Overlay: salinity occurrences and mapping. This report focuses on the area of the Surf Coast Shire which is a part of the Barwon region.
The report identifies 287 mapped sites with 32 percent being land salinity sites but doesn’t provide salinity levels for each site.
Several agencies were contacted after their websites failed to provide up to date levels, including the Corangamite Catchment Management Authority, Barwon Water and Department of Energy, Enviroment and Climate Action. Barwon Water did not respond to the enquiry while other agencies provided
outdated data, making it difficult to determine current salinity levels in the Barwon region.
What is being done to reduce salinity?
While local councils support broader initiatives, Barwon Water a government owned statutory body commenced a $25 million project in November 2021 to build a water reclamation plant in Portarlington aiming to produce 450 million liters of low salinity, recycled water to the Bellarine Peninsula per year.
The Australian Government contributed $5.53 million and Victorian Government contributed $1.97 million to the fund.
Minister for Water of Victoria at the time, Lisa Neville, said that the project is aimed at providing reliable, year-round water access for local farmers, particularly during dry periods.
Construction of the plant is underway and expected to finish by mid-2026.
This story is part of a project exploring regional Victoria and the issues farmers are facing. See the whole collection here.
