Planning helps save water for Stewarts
The Stewarts run a small prime lamb enterprise on 100ha. Their undulating property has granite-based sandy loam soils rising to rocky granite outcrops. The rocky outcrops had been fenced off, leaving 2 main cropping paddocks and 3 smaller paddocks – but just 2 dams to water the stock.
'We'd previously farmed in South Australia where we were used to having a bore with a windmill, or a tank and trough in every paddock,' recalls David, who farms north of Benalla.
'Having to rely entirely on surface dam water was an experience we had little knowledge of, and didn't feel very comfortable about,' David said.
'The stock were allowed to walk through gateways to access paddocks with water,' says David. 'This essentially made grazing management impossible.'
With the couple intending to grow lucerne, which requires a rotational grazing system, it was clear that significant changes needed to be made to the farm layout and the watering system.
Change to farm layout and water system
They developed a whole farm plan which included reticulating water to where it was needed in a bid to provide much improved water security.
They decided to build a larger dam in the best catchment, and install a reticulated water system comprising a header tank, poly troughs and piping across the entire farm.
Dividing the farm according to soil type
Their whole farm plan divided the property according to soil type – specifically, its suitability to grow lucerne. This resulted in the 2 larger cropping paddocks being subdivided into 9 smaller paddocks, each requiring its own trough.
The other paddocks also required troughs, both as a back-up for when the dams run dry, but also because the stock noticeably prefer to drink the clean water from the troughs.
Diverting the water from tank to troughs
Working to the farm plan, they installed a 30,000-litre header tank at the highest point of the property. An electric pressure pump was installed at the dam to deliver water to the tank (a head of around 25m).
The water is then gravitated to the troughs via 40mm piping. All the lines have been set up with gate valves to isolate paddocks that are not being grazed.
Maintenance and monitoring of water system
In summer, the tank's capacity represents approximately 10 days' supply, but, as with any other watering system, it requires monitoring every couple of days.
Occasionally the pump has required repairs or maintenance, but there has normally been adequate water in the tank to continue watering the stock during that time.
The system works well, enabling David to rotationally graze the entire farm. This is generally a maximum of 5 to 7 days, followed by a rest period of between 28 to 37 days, depending on the season and paddock size. But it is only effective while there is an adequate water supply.
Reducing evaporation of dams
Tools for measuring dam volume, evaporation and livestock drinking requirements: