Laptop controlled irrigation revolutionising farming

Efficient management of water in some of the driest, most drought affected farming areas in NSW has reached a new world standard thanks to automated ordering systems that allow irrigation farmers to control water delivery at the touch of a keypad.

Coleambally Irrigation Co-operative Limited (CICL) is a co-operative business that manages infrastructure, systems and services for delivering water to and from more than 450 farms in the NSW Riverina region.

The CICL sources its water from the Murrumbidgee river, through an open channel system whose main canal can flow at up to 6000 megalitres a day. The majority of farms it services are 200 hectare farms growing large area crops such as rice, sorghum, soy beans, maize, wheat and barley.

The CICL system delivers water to farms through some 700km of channels, driven emission free by gravity. The farms that CICL services have suffered their worst two years on record for water allocations, and have endured severe drought conditions since the turn of the century.

But an automated water management system from Rubicon Systems, rolled out in 2003 and due for completion next year, is helping to turn the tide in the farmer's favour when it comes to efficient delivery and use of water.

There are about 700 outlets in the CICL system, 100 of which are automated FlumeGates that, upon receiving an order for water via a farmer's computer, can deliver precisely the amount of water required without any human interaction, and in a fraction of the time it would take under manual control.

CICL's senior operations engineer, Austin Evans, said the automated outlets can deliver higher flow rates which help the farmers water their farms more efficiently. They can get their water on quickly or turn it off from their laptops, improving their field efficiency.

"A lot of our guys, if they are doing row cropping and running siphons, will start their outlets in the middle of the night and when they get up at 7am all their head ditches on the farm are full and they can go and start their siphons. Whereas with the manual system a water officer opens the outlet at about 8am, it takes until midday to fill up, and then the farmers have got to come back at midnight to change them over again," Evans said.

The new automated system therefore allows the farmers to work more reasonable hours and gives them more control over their water distribution. If there is rainfall predicted they can shut off the water from their computers within two hours, compared to the old system that would require a water officer to manually shut the water off, or on, which would typically take from 18 to 24 hours.

"So you would have all this water running in that the farmers don't want, so they are making a lot of savings," Evans said.

But the benefits aren't limited just to the farms. The CICL is several days travel from the dams to their offtake, with only a couple of regulation points in the river between the two. A manual system has difficulty coping with sharp peaks due to heavy rainfall, taking up to a full week to settle down to a constant flow rate.

"The automated system can get it under control within a day," Evans said.

"The other thing is manual systems are basically designed to have overflow at the ends of the channel, whereas with this system the biggest area we have saved in is in stopping those flows going out the end of the channel, without compromising the service we give to farmers."

The remaining 600 outlets in the CICL system are comprised of about 400 Dethridge wheels, which have been criticised for inaccuracy, and several hundred other types of meters and propellers. The CICL plans to replace the remaining 400 Dethridge wheels with automated FlumeGates by the end of Winter 2009.

At a cost of $18 to $25 thousand per outlet, the CICL has spent around $15 million on automated channel regulation so far, and predicts a total cost of $25 million to automate the entire system. The network management technology has ensured a world standard of 90 percent efficiency in water delivery, well above the 73 percent average, and has boosted water allocation by up to 18 percent because of those savings.

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Rubicon's Total Channel Control system

Gino Ciavarella is the software development manager and a director of Rubicon Systems, a provider of specialist operational technology to the water and utility markets.

According to Ciavarella, the Total Channel Control (TCC) system used on Coleambally's farms runs on a Windows platform and is underpinned by relational database technology. The system can be run on Oracle, SQL Server or Ingres database engines.

"The database is processing millions of transactions per day with real time data coming in from the SCADA network and from irrigators placing their water orders online using the Internet and interactive voice response (IVR) system interfaces.

"We've got a water ordering component which takes care of all the customer's irrigation orders. We automatically schedule water order requests online using our Demand Management System software to deal with capacity constraints in the network and automatically reschedule them if required and then provide that information to the control system which then completely automates the delivery using the network of FlumeGates installed," Ciavarella said.

The computer system stores the irrigation channel network topology in the database so that how water flows from one point in the network to the other and what the demand is at any point in the network can be monitored, which is critical for determining whether there is capacity or supply constraint.

"So when the customer orders water they are asked for information about when they want to start, how long they want to water for, how much water they want to take in terms of a flow rate, and that is then downloaded into the FlumeGate out in the field over the radio network in seconds, and the gate will then open to deliver the irrigation," he said.

"We manage all the infrastructure for the TCC system and also use the FlumeGate as a communication node onto the farm, so they can get data from soil moisture probes that get inserted into the ground back to the central computer . That information is transmitted through a broadband radio backbone which we also roll out as part of our TCC systems."

Rubicon is currently interfacing its system into weather stations to further increase farmer's abilities to respond to climatic changes through its FarmConnect project.

"FarmConnect is using information captured from soil moisture probes on farms and using climatic data as well to predict when the irrigators will need to irrigate again. We've have had a trial in five farms for 12 months and its proven to be very beneficial.

"The irrigators have actually saved water in terms of having to irrigate less often because they have got more precise measurement of how their water is being used on the farm, and they realise they can save one or two irrigations which stretches that valuable resource a bit further," Ciavarella said.