AFTER spending large sums of money to cart water to areas that have been declared water deficient in recent years, the State government has invested in a desalination trial to improve Western Australia's rural and regional water security.
Community desalination units will be built in the Shires of Merredin, Katanning and Dumbleyung to test desalination technology from the WaterSmart Farms program.
Desalination units use a reverse osmosis process to remove salt and impurities from groundwater to produce fresh water, suitable for livestock, crop spraying, horticulture and garden use.
A key component of the desalination trials will be the safe and efficient discharge of reject water, so it does not damage the environment or affect downstream neighbours.
Department of Primary Industries and Regional Development (DPIRD) senior principal research scientist Richard George said the department's WaterSmart program had been designed with three key focus areas in mind.
"We need to get behind the farmers that have already invested in desal and find out how it's going and do some measurements and that's what Murdoch (University) is up to," Mr George said.
"We want to demonstrate desal in good operating conditions, so we had the idea of running smaller pilot projects.
"Then we wanted to spend some dollars trying to find water in places where it unconventionally had never been looked at in the past and that's going to the next level to try and get a secure and more reliable water supply."
A brackish water desalination unit will be installed in Katanning this summer as part of a network of demonstration sites to examine how the technology can help overcome seasonal variability, reduce reliance on scheme water and support community development.
The Katanning unit will supply 30 kilolitres per day of fresh water to augment services for three local parks, as well as other town infrastructure.
Shire of Katanning deputy president John Goodheart said they were similar to a lot of other regional towns, in that it had been reliant on rainfall and "back up" from the water authority to fulfill the town's water supply.
While some new infrastructure will need to be built for the project, the town's existing water infrastructure contributed to it being a suitable test site for the desalination trial.
"The long-term outcome is that not only our town will benefit from it, but the things that we learn from this process are going to be transferred to other towns that need the same kinds of resources," Mr Goodheart said.
This summer a 100kL/day desalinisation unit will also be installed at Merredin to service farm and town water needs, while a new 10kL/day salty groundwater system at Dumbleyung will service farm and town water supplies, as well as underpin repairs to the town's swimming pool.
After Dumbleyung was declared water deficient about two years ago, the local shire, along with the State government invested in projects focused on capturing and storing water for the town, however Shire of Dumbleyung chief executive Gavin Treasure said the town required a more stable source of water and was hopeful the desalination trial would deliver some positive results.
There has increased interest in onfarm desalination units and the owner of Crossburn Farm, Kojonup, Adrian Bilney, is one farmer who is testing the new technology.
For the past few years he has been carting water and using scheme water for his 30,000 sheep.
"In 2020 we found ourselves in a position where all our dams were going dry and we ended up being heavily reliant on a scheme connection at another farm, which we were carting water from for a long period," Mr Bilney said.
"We were spending our whole time chasing our tail...so we decided we needed to do something for the future, because scheme water might not keep coming out of the pipe.
"So far, this (project) has been a really good thing."
More than 50 desalination units have been established on Wheatbelt farms in the past three years.
The project, led by DPIRD in partnership with the Water Corporation, will also undertake case studies to examine the life cycle costs and efficiency of these new systems.
The government's $1.5 million WaterSmart Farms project will also involve an inventory of about 50 onfarm desalination plants to capture the learnings and experiences of farmers to extend to the broader community.
The project is working with Murdoch University, Curtin University, the Department of Mines, Industry Regulation and Safety and the Grower Group Alliance on a targeted groundwater exploration program to identify previously untapped brackish to saline groundwater supplies.
Agriculture and Food Minister Alannah MacTiernan said while recent rainfall in the agricultural region had been favourable, now was the time to invest in how to future-proof farming operations and regional communities so they are set up and well-resourced to manage the dry years.
"The greater use of groundwater can also help lower the water table and reduce salinity," Ms MacTiernan said.
Water Minister Dave Kelly said long-term statistics showed WA was experiencing reduced rainfall due to the impacts of climate change, with a record 12 water deficiency declarations announced just two years ago in the Wheatbelt.
As part of the collaboration with the National Water Grid Authority, a further 30kL/day brackish water off-grid reverse osmosis unit will also be installed at the Wongutha Christian Aboriginal Parent-Directed School at Esperance.
