Drought years are proof that there’s more ‘crop per drop’

Two very dry years show that investments by both farmers 
and irrigation districts have greatly increased water-use efficiency

They were the two driest growing seasons in recent times — but when you look at water used for irrigation, 2001 and 2015 are very different.

Last year, the amount of water diverted by the Eastern Irrigation District (EID) was almost 200,000 acre-feet less than in 2001, even though the number of acres under irrigation, now approaching 300,000 acres, had increased.

It was a similar story in the Western Irrigation District (WID), which supplies irrigation water for about 96,000 acres. Its diversion in 2015 was 25,000 acre-feet lower than in 2001.

There are two main reasons for this difference — changes farmers have made to their equipment and improvements in the water delivery systems.

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“The water users are a big part of ensuring we have efficient water use in our district, and their investments make a huge difference,” said Erwin Braun, WID general manager.

In 2001, only 20 per cent of the irrigation in the district was done using low-pressure pivots. By 2015, that had increased to 54 per cent. In that same time period, flood irrigation nearly disappeared — falling from 25 per cent to just three per cent.

The EID saw similar improvements by its water users — flood irrigation has fallen by half since 2001 while low-pressure pivots are used on 62 per cent of acres (compared to 23 per cent in 2001).

“Changes that they’ve made make them much more efficient — going from flood irrigation to pivot irrigation to low-pressure pivot irrigation,” said EID general manager Ivan Friesen.

The Eastern Irrigation District has nearly tripled the number of kilometres of pipelines since 2001.

The Eastern Irrigation District has nearly tripled the number of kilometres of pipelines since 2001.
photo: Eastern Irrigation District

Low-pressure pivots are currently the most efficient on-farm system, with about 85 to 98 per cent application efficiency. They also save time and energy, making them a valuable investment for water users.

“I think it’s that farms are getting larger and everybody wants to become more efficient,” said Friesen. “I think pivot irrigation has been proven to pay. They can put a half-inch on when they need it versus flood where obviously you can’t use that kind of precision irrigation.”

While both general managers are quick to give credit to their water users, the districts have also made big improvements to their infrastructure.

“We’ve rebuilt a lot of the canals — they’re now lined, don’t leak, and we can provide a lot more of the water we divert to the farmer,” said Braun. “We’ve also converted a lot of canals to pipeline, and those are a lot more efficient. They don’t leak, there’s no evaporation, there’s no seepage. All of the water in the pipeline goes right to the farm.”

In 2001, the WID had just 67 kilometres of pipeline, but in 2015 that had increased to 333 kilometres. The EID went from 481 kilometres of pipeline to 1,165 kilometres in that same time frame. By making their systems run more efficiently, they can deliver the water in a timelier way to their end-users.

“The Alberta Water for Life Strategy set out guidelines for us,” said Friesen. “We felt we have met those guidelines set out before us. So that was a driver for us as well.”

But both general managers said there is a lot more work to be done in order to be prepared for drought years in the future.

“We’re always striving to be better,” said Friesen, noting the district has an ongoing three-year rolling plan for rehabilitation projects. “Now we continue with an aggressive rehab program so that we can always become more efficient.

“Landowners are doing the same. We’ve got roughly 75 per cent of our district under pivot irrigation and I think in 2001 it was more like 45 per cent so we’ve made big gains there.

“We’ve got another 15 per cent to go. I think 90 per cent pivot is achievable.”

Comparing water usage in 2001 and 2015 shows investing in improvements was worthwhile, said Braun.

“When we compare these two years, we are a lot more drought resilient,” he said. “That’s a good thing.”

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