Irrigation upgrade to save 10,000 megalitres a year
Tinamba West dairy farmer Alister Clyne reckons he can save a whopping 300 megalitres of water this year thanks to an investment in irrigation technology.
The staggering on-farm saving marries with the most recent $60 million phase of the Macalister Irrigation District (MID) upgrade, expected to save the district 10,000ML of water annually.
The largest irrigation area south of the Great Dividing Range, the MID sprawls across 53,000 hectares of central Gippsland.
Of this, about 33,500ha is irrigated with 146,367ML of high reliability water shares fed largely through channels dug in the 1920s and 1950s.
Southern Rural Water (SRW) staff walk the channels daily, manually opening and closing an antiquated set of gates to direct flows in response to customer orders.
Dethridge wheels, whose average error rate of 7.5 per cent depends on things like age and even the growth of water weeds, measure how much water properties receive.
All that is changing.
In this phase of the project, 31 kilometres of pipe with automated valves is being laid to service 73 farms in the Tinamba and Newburn Park districts.
This season, farmers will order water 24 hours, seven days a week using their smartphones.
When an order is placed, SRW’s radio network will tell solar-powered controllers to open SRW’s giant blue valves accordingly, regulating flows to meet customer demand.
SRW construction manager Matt Weatherall said the benefits were obvious.
“Water’s not being lost through leaky channels, farmers can have water delivered any time they want it so long as it’s there, it’s safer for SRW staff and farmers and it’s much more accurate,” Mr Weatherall said.
The massive works brought hundreds of earth-moving machines onto farms, most of them busy dairy operations, along with significant disruption.
The key to making it all work, according to SRW communication and engagement advisor Anna Larkin, was farmer consultation.
While she concedes “it doesn’t mean farmers are always happy”, Ms Larkin said collaboration between farmers, contractors and project managers had been critical.
“We were obliged to replace the current gates as they were, but consulted with farmers about what they really needed and found we could make big savings,” she said.
“A farmer, for example, suggested following the road instead of taking the current route diagonally across his paddocks, which saved the project money and the farmer a lot of hassle.”
In all, consultation and redesign has rationalised 215 outlets down to 88 new outlets.
ON-FARM TECH MEETS DISTRICT TECH UPGRADE
Caption: Southern Rural Water construction manager Matt Weatherall shows off the automated valves that replace antiquated gates and Dethridge wheels.
Rationalisation has been a long-term project on Alister and Katie Clyne’s 1500-cow dairy operation and began independently of the district-wide project.
One of the Clynes’ two properties put 1500 metres of pipe in during 2015/16, removing four outlets in the process.
The payoff was an improvement in the flow rate by almost 50pc in readiness for full on-farm automation.
Mr Clyne said he had invested more than $600 a hectare on automating irrigation across chunks of his farm.
Despite the odd technical glitch, automation had made a massive difference.
“It means not having to go out for an hour every six hours,” he said.
Even so, flood irrigation on the free-draining loamy soils was problematic.
“We were putting 65 millimetres on, even though 50mm would be ideal,” he said.
“We knew the SRW pipeline was coming, so we asked ourselves, ‘what do we do next?’.”
The natural place to start was a river flat that was yet to be modernised and was served by three outlets and a river outlet.
“It was a high watering soil type and we were putting 80 to 100mm on that,” he said.
“We knew we could get the same production with 20 to 30pc less water.
“Pivots or any form of spray irrigation are the only way to go on our soil types.
“It’s better for the grass, better for the soil and it you get better quality pasture with fewer weeds, especially docks.
“We were talking rationalisation with Geoff Enever from SRW and worked out we could do away with three wheels and 600m of of spur channel by using a pivot from the river outlet.”
Because the rationalisation brought savings for the MID modernisation project, SRW made a co-contribution to Mr Clyne’s shift from flood irrigation to pivots.
The use of pivots has also bought the Clynes’ business precious time and flexibility.
“I can control irrigation with my phone and operate it in off-peak hours without having to go out into the paddock,” Mr Clyne said.
“Sometimes it still doesn’t go because it gets bogged or whatever and I would have had to come out here at midnight then milk the next morning.
“Now, because I only need to put on 7 or 8mm a day, I can leave it until daytime knowing I can catch up again within 24 hours.
“There’s a whole six hours of watering you don’t need to do.”
Another 75ha block belonging to the Clynes has been similarly converted from flood to pivot irrigation.
There, SRW and Mr Clyne again managed to design out hundreds of metres of pipeline and four outlets, generating more savings.
Mr Clyne thinks his on-farm upgrades will have a payback of six to seven years taking both water savings and increased productivity into account.
“If I water flat out, there’s a saving of 300ML a year,” he said.
“This farm used 750ML on average but to water all year, it would need 1000ML but we would dry 25pc of it off and focus on what we could water through.
“I think we will grow 15 to 20pc more feed.”
Originally published by Farm Online.
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