Understanding the big role of small farm dams

Farm dams are the lifeblood of rural Australia, providing water for crops and livestock but their limited capacity to store water for extended periods and reliance on regular rainfall to top up makes them vulnerable during droughts.

Federation University researchers are playing a leading role in a project to improve the understanding of small farm dam hydrology and help improve decision making during times of drought and a future impacted by climate change.

The three-year, $1 million project led by Southern Farming Systems will see researchers from the Future Regions Research Centre (FRRC) and the Centre for eResearch and Digital Innovation (CeRDI) team up to look at whether farm dams will be as useful in the future as they have been historically. The project is part of the Victorian Drought Resilience Adoption and Innovation Hub and is funded by the Federal Government’s Future Drought Fund.

Associate Professor Andrew Barton from the FFRC said small farm dams played a crucial role in regional and rural Australia, but little was known about their hydrology.

"When there's a dry year – a dry summer or winter – most farm dams will be low, but they'll tend to get through. But in the context of a continuing drying climate and droughts becoming more frequent, having good water security is becoming more of a problem," he said.

"Because farm dams aren't big water supply systems, they haven't attracted funding for research in the past, so there's much to learn. To help with our understanding of farm dam hydrology, we'll establish several case study sites across Victoria to try and understand what happens to the water when it rains – how much and where does that runoff end up?"

The project will see the rollout of instrumentation across several Victorian farms to measure rain and runoff. Rain gauges, water level sensors in dams and other measuring instruments will provide data from equipment that farmers usually don't have access to.

Once the data is collected, the researchers and partners in the project will develop water balance models that will give an insight into what runoff can be typically expected from different types of rainfall.

CeRDI will create a spatial tool to allow the rapid calculation of the likely runoff for different rainfall – the frequency and volume under current and future climate scenarios – into existing small dams to help farmers prepare, cope and recover from drought. This type of interactive calculator does not exist, with current approaches designed for flood planning rather than drought planning.

The results will be combined with existing tools and calculators available through Agriculture Victoria to enable farmers to assess and plan the adequacy of their current farm dams to capture sufficient water for their operations with a drying climate and future droughts.

"Once we have an understanding of how farm dams work within a hydrological sense, we can put that information on an interactive map. For example, with the help of aerial imagery and photos, a farmer can find their property and their dams on an interactive map, and they can click on elements to understand what happens if it's a dry year, understand what the runoff is, and what the likely drought impact for their farm dam might be under a particular scenario," Associate Professor Barton said.

"The translation of science into easy to use and practical tools can often be difficult. But with CeRDI placing information into an interactive map, landowners will have a convenient and effective tool for getting the information they need at their farm level. This project is very much about providing a tool so that we can help farmers understand or navigate their way through climate change." Associate Professor Andrew Barton

Associate Professor Barton said the research would arm landowners with the knowledge to make informed decisions about their dams to keep themselves viable, sustainable and productive. In a changing climate, this information will provide farmers with a level of detail that they've never had before and could set their course for future generations.

"You don't have to look far to see the evidence of a changing climate and extreme weather events. We've seen catastrophic floods in Queensland and New South Wales, and these extreme events are happening seemingly more frequently," he said.

"It might be a flood in one part of the country and drought in another – there might be a few normal years, but then it will come back again. In the context of the agricultural sector, billion-dollar industries are affected."

Associate Professor Barton said there was also significant public good in this proposal.

"Water is the lifeblood of farms, to enable the retention of livestock, to maintain farm gardens and recreation. The mental and social value of access to water is immense. The on-farm benefits then flow through to the wider community, especially in the drought recovery phase because businesses are in a better state of mind," he said.

"Farm dams are iconic in the Australian landscape. When you're driving along in rural or regional areas, farm dams are everywhere. They don't just serve a practical water supply purpose, there's a lot more to them than that."

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How data could change life down on the farm

Unlocking the potential of farm data

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