More accurate picture of ‘actual’ water use emerging

A more accurate picture of ‘actual’ water use in Canterbury is emerging as growing numbers of the region’s irrigating farmers provide water monitoring data to Environment Canterbury, says IrrigationNZ.

The regional council’s 2013/14 Water Use Report includes data from more than 50% (50.4%) of all consented surface water and groundwater takes in the region. Last year’s report contained water monitoring data from less than 40% of Canterbury’s takes abstracting water at a rate of 5 litres per second or more.

“That leap alone shows significant progress is being made. Farmers are getting the message that they need to install water metering systems, not just for compliance, but to improve their irrigation efficiency and nutrient management. Now we have more than 50% of Canterbury’s water takes being monitored we’re getting closer to a true picture of ‘actual’ water use based on real-time data that farmers are willingly providing,” says Andrew Curtis, IrrigationNZ CEO.

“While all farmers should be metering takes over 20 litres a second, IrrigationNZ is well aware there are challenges associated with monitoring. It’s not as simple as just sticking a meter on as there can be complications with data management, technology failures and ensuring data is of sufficient quality. We applaud those who have persevered and addressed these issues as it’s critical any data going into the regional council is robust and can withstand scrutiny,” he says.

Mr Curtis singled out farmers in the Christchurch West Melton, Upper Waitaki and Kaikoura Zones for particular congratulation. “These areas experienced the largest increase in monitored water takes over the past year. IrrigationNZ applauds irrigators in these catchments for getting on board with water monitoring,” says Mr Curtis. (Christchurch West Melton increased from 39 to 51%, Upper Waitaki 32 to 57% and Kaikoura 44 to 51%).

The districts with the highest number of water monitoring sites were Ashburton Zone with 73% and the Orari Opihi Pareora Zone with 72%.
Marked differences in the way communities within Canterbury used water during the year reflected unseasonal weather patterns last summer, as well as localised irrigation events, says Mr Curtis.

The September 2013 wind storm, which damaged more than 800 irrigators across the region, delayed the onset of irrigation for some farmers in the worst affected areas within Waimakariri, Selwyn and Ashburton Districts.

But a bigger factor was variable weather patterns, with rainfall higher than usual in many areas, particularly during early spring and autumn.
The biggest users of allocated water were Ashburton Zone (64.34%), Lower Waitaki – South Canterbury Coastal (62.69%) and Waimakariri (59.69%). The year prior Ashburton Zone was joined by the Orari-Opihi-Pareora, Ashburton and Selwyn-Waihora Zones as the catchments recording the highest consumption of allocated water.

While high rainfall in autumn brought the 2013/14 irrigation season to an early close across much of Canterbury, Mr Curtis says patchy rainfall during November 2013 to February 2014 reinforced the need for reliable water supply even in what was supposed to be a “wet summer”.

“This report shows even when we get a wet spring and wet autumn, we still need a reliable irrigation supply over the four key growing months of November to February. Soils can dry out quickly even after prolonged periods of rain when temperatures rise and many crops require constant and strategic application of water so we can’t be complacent about the need for irrigation even during seasons of above average rainfall,” says Mr Curtis.

Mr Curtis says irrigators would continue to make efficiencies in how they used water to ensure sustainable management of Canterbury’s water resources. “Our SMART irrigation programme rolled out earlier this year supports farmers in keeping up with the technologies, skills and management systems necessary to drive water efficient irrigation. We’re also continuing to talk to central and regional government about the allocation and transfer system for water takes. These need to be dynamic if we are to drive the best possible return to the community from New Zealand’s natural resources.”

To view the Environment Canterbury Water Use Report for the 2013/14 season check out

Further comment:
Andrew Curtis: Irrigation NZ Chief Executive – 03 341 2225 or 027 496 6314.