Tasmanian irrigators pioneer high-tech, localised water management
Ever since the ancient Mesopotamians began diverting water from rivers to irrigate their crops, farmers have used engineering technology to insure against dry times.
A project in Tasmania’s Ringarooma catchment, in the island’s northeast, is now bringing this ancient engineering scheme that transformed agriculture into the data-driven 21st century.
The Ringarooma Valley, according to a 1925 Minister of Mines report, was opened up to agriculture in the 1860s, with “first-class basaltic soil … particularly suitable for potato-growing, dairy-farming, cattle-raising, as well as other branches of the agricultural and pastoral industries, which have made the district a very prosperous one”.
Water from the Ringarooma River has made it possible.
As technology and understanding of river flows has improved, that has meant a rhythm of farming life in the Ringarooma punctuated by disruptive ‘cease to take’ orders from regulators when water flow has dropped to critical levels.
Today, a group of local farmers, working with CSIRO, the University of Tasmania, and the Tasmanian Farmers and Graziers Association, is using high-tech, remote sensing technology, along with community collaboration, to support irrigation decisions that meet the water demands of both agriculture and the local environment.
Local conditions require a local response
This Sense-T project was borne out of a desire for a more adaptive approach to water management that can respond to the unique conditions – and needs – of an individual catchment, says Andrew Aldridge, a Ringarooma dairy farmer.
The state water regulator normally relies on an array of sensor networks across the state to inform day-to-day decisions on water and irrigation restrictions. But these operate at a ‘macro’ scale, Aldridge says.
“There were concerns raised by the farmers that the state’s water policy was not necessarily taking into account the active requirements of this particular river and this particular catchment.”
For some time, the Ringarooma community had indicated it wanted a more locally-tailored water management approach. Several years of consultation with the regulator had led to adaptive management being permitted in the formal water management plan for the catchment, but the technical and social mechanisms to implement it were lacking.
The Tasmania Farmers and Graziers Association was very keen to be involved on behalf of their members and the Ringarooma turned out to be the perfect collaborative testing ground for Sense-T, according to Brigid Morrison from TFGA and the University of Tasmania.
During the project, Ringarooma proved they had the capacity to make and implement decisions as a whole community.
In one situation, the community got together to voluntarily implement a ‘cease to take’, where all irrigators agreed to not draw any water from the river system for 24 hours, to see the effect it had on baseline river flows.
“That group had a particularly strong sense of community but also they were prepared to take a risk, and that’s a prerequisite for good innovation and leadership,” she says.
Gauging the data flow
To begin with, researchers from CSIRO and the University of Tasmania looked at the sum total of sensor data – both private and public – available for the catchment, including water meters, rain gauges and soil moisture sensors.
Where they identified gaps in the sensor array, they installed their own sensors. They then took the feeds from all these sources, combined them with a feed of data from the Bureau of Meteorology, and set up a website to process and present all that information in an easy-to-understand form that would update every 3-6 hours.
At the same time, the Ringarooma Water Users Group formed, representing the 70 farmers and graziers across the region, and industries ranging from dairy to hops. The group was entrusted by the regulator with the responsibility for making day-to-day decisions about irrigation in the catchment, using the information provided by Sense-T.
Dr Philip Smethurst, research scientist at CSIRO, says a novel aspect of the project was that it was able to provide local forecasting services for stream flows or rainfall to the Ringarooma Water Users Group.
“That was quite useful to them, and we ended up providing daily updates of that streamflow forecast, and also at one location sub-daily indications of the way flow was expected to go,” Smethurst says.
During times of water shortage, the group would consult that data several times a day and make decisions about whether it was safe for local farmers and graziers to irrigate and still maintain adequate environmental flows in the catchment. These decisions were then communicated to all the farmers and graziers in the region via a text-messaging service provided by the regulator.
They even went so far as to divide the catchment into three irrigation groups to fine-tune their decisions to local conditions, Aldridge says.
“We were changing the time and frequencies of our watering, so we were changing when people were watering and how they were watering,” he says. “So basically we changed our entire pumping practices in a bid to maintain a level of flow in the river.”
Shared responsibility saves on lost productivity
By all measures, the approach has been a success. In what was one of the driest periods in recent history for Tasmania, when the catchment should have been on irrigation restrictions for much of the irrigation season, the Ringarooma group got through most of the year without any ‘cease to take’ orders.
An economic analysis of the intervention, based on interviews with 11 farmers, found that it saved $1.5 million in just one season from avoided loss of productivity.
Morrison says the project couldn’t have succeeded without a high level of connectedness in the community, and a willingness to participate.
“I think the biggest lesson learned is that solving wicked problems requires a cross-section of participants; everybody had to contribute something and everybody had to concede something,” she says.
It also needed the state’s water regulator to place their faith in the community’s ability do the right thing with that responsibility.
“There has been significant progress made in communication and relationship building with the regulator, who has allowed this to happen whilst keeping a close eye,” Morrison says.
While the project has officially come to a close, the Ringarooma group is continuing to champion the cause of local adaptive water management, Aldridge says.
“We’ve still got the management group and we still do the active management,” he says. “We’ve tried to develop a greater credibility inside government to ensure that we know what we’re talking about when we do what we do, and that we are actively interested in water management and looking after the environment.”