Using Water Level Sensors To Solve Australian Irrigation Issue

- Sep 21, 2019-

Irrigation management is critical in Australia, especially the Murray-Darling Basin, a watershed covering an area of 1,000,000 square kilometers. It is home to Australia's most productive agricultural land. The Murray-Darling basin has been under pressure since the 1960s, but in the 1990s, a series of economic and environmental crises provided the impetus for changing water management practices.

Murray irrigation operation

Australia's largest private irrigation company, Murray Irrigation, processes irrigation upstream of the Murray River in southeastern New South Wales. Their system covers approximately 750,000 hectares of land through nearly 3,000 kilometers of gravity soil channels, distributing water to more than 2,300 farms.

Managing this decades-old irrigation system is a complex task. Based on weather, soil conditions, crop maturity and other factors, farm customers require seasonal distribution of water. Water orders must be allocated seven days in advance for coordination, but many waters can be changed in the farmland within seven days.

Transporting water through a spider web of surface channels is a complex manual process. Therefore, regardless of the customer's location in the distribution system, each customer receives their water distribution and needs to balance the water level and emissions of each channel.

In addition to the daily needs of municipal and industrial customers, Murray Irrigation must balance the requirements of 2,300 farms – while remaining within the Murray allocations specified in the Murray-Darling Basin program.

Historically, the system was manually managed through mechanical water meters and channel control door systems. In order to discharge water to the downstream channel, the irrigator will travel to the channel control point and raise the gate to a certain height for a specified period of time.

Dozens of people on more than 3,000 kilometers of channels will try to coordinate the water level so that each farm customer gets the water distribution they need when they need it. Typically, to monitor consumption, the customer's water usage is measured using mechanical meters that must be accessed periodically.

In order to ensure that end customers get the amount of water they are entitled to, a large amount of emergency drainage is required and there is sufficient flow to achieve consistent field irrigation. The system is inaccurate and labor intensive, but it is cost effective as long as the water is sufficient. More efficient systems are essential due to daily water shortages and destructive droughts.

Murray Irrigation launched the Private Irrigation Infrastructure Operator Program (PIIOP) in 2013 to reduce water distribution losses for nearly 3,000 kilometers of long channels.

Since its inception in 2013, it has replaced more than 1,000 irrigation control points. In the next phase of the project, a sensor-driven automatic door using a water level sensor will replace approximately 1,200 channel control points.

Murray Irrigation is applying two levels of system automation. The irrigation control point is remotely controlled in the standard service level (SLOS) area. A ToughSonic ultrasonic sensor mounted near each gate provides water level measurement data for Murray's SCADA system.

To release water based on known time and volume parameters, the control center operator monitors the water level and channel level and issues a remote gate movement command. The system responds accurately and allows farmers to adjust water orders every 12 hours.

To determine the amount of water delivered, the system monitors the water level data from the ultrasonic level sensor and other sensor inputs. The HLOS system allows irrigation users to order four waters per day, allowing the entire system to flow.

The water is dispensed accurately and there is no need for a large and potentially wasted emergency release in these two service areas. Farmers benefit from more stable flows and shorter lead times, enabling them to irrigate crops more accurately, maintain healthy crop yields, and reduce overall water use.