Irrigation investments, programs playing a big part in water conservation

A soon-to-be-published study estimates 170 million to 200 million cubic metres were saved from 1999 to 2012

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Alberta producers and irrigation districts are making great strides toward conserving water, with both grants and individual investment producing tangible water and energy savings.

Those efforts produced overall water savings of 170 million to 200 million cubic metres in Alberta’s 13 irrigation districts from 1999 to 2012, said Rod Bennett, director of Alberta Agriculture and Rural Development’s Irrigation Management Branch.

In a paper about to be published in the Canadian Water Resources Journal, Bennett used data on irrigation infrastructure, system type, crop mix and weather information. About 50 million cubic metres of water savings came from conveyance — getting the water from the diversion source to the farm gates. This doesn’t vary greatly year to year, unlike the on-farm side of the demand, where the water savings range from 120 million to 150 million cubic metres.

Part of these savings are due to programs like the Irrigation Rehabilitation Program. Under the cost-sharing program, the province pays 75 per cent and irrigation districts 25 per cent of the cost for upgrading canals and infrastructure to reduce water losses from evaporation and seepage, as well as improved delivery.

But the lion’s share of the water savings is from reduced on-farm demand.

“It’s the private investment on the part of irrigation producers that have resulted in 70 to 75 per cent of the total reduction in water demand,” said Bennett.

water canal
The rehabilitation of the Secondary A Canal in the Western Irrigation District was completed last year, with 93 kilometres of the canal rehabilitated from 2001-14 at a cost of $52 million. photo: Western Irrigation District

Low-pressure pivots have played a major role in that. In 2012, more than 68 per cent of the 13 irrigation districts were irrigated with low-pressure centre pivot systems. This is a huge jump from 35 per cent in use in 1999.

Federal-provincial cost-share funding initiatives under the Growing Forward 2 irrigation efficiency program have helped to drive those changes.

“This program provides 40 per cent rebates of up to $5,000 per producer for investments in new or upgraded low-pressure centre pivot irrigation equipment,” said Bennett.

The list of eligible equipment is extensive, including new low-pressure centre pivot equipment, converting high-pressure systems, and upgrading existing low-pressure systems. Upgrades could include replacing worn-out nozzles, pressure regulators, and new control panels on pivots

“The new panels allow producers to change their settings or turn systems on and off using their cellphones or a tablet,” Bennett said.

Another option is to add variable-rate irrigation system components for precision irrigation.

Initiatives under the Alberta Climate Change Strategy from 2008 to 2011 saw $700,000 in grants paid out to about 200 producers. In just the first year of the Growing Forward 2 irrigation efficiency program, 156 producers were provided with more than $715,000 in grants. Year two saw 128 grant payments of about $560,000.

But there is still a lot of room for improvement.

As of 2012, there were still about 48,000 hectares irrigated with high-pressure systems, and 115,000 hectares with wheel move and gravity irrigation systems.

“Not all wheel move or gravity systems will be replaced by low-pressure centre pivots because of field size, shape, or affordability,” Bennett said. “There’s no reason why high-pressure systems shouldn’t be converted to low pressure, though. We estimate that they can save about one-third of their energy, going from high pressure to low pressure.”

If moving from wheel move to low pressure, the energy costs savings could be more than 40 per cent.

Further improvements are planned for the conveyance side. As of 2012, there was still more than 1,600 kilometres of canals left to be rehabilitated.

Bennett’s paper (co-authored by Bob Riewe, Toby Entz, and Shelley Woods) Water Conveyance and On-farm Irrigation System Efficiency Gains in Southern Alberta Irrigation Districts from 1999 to 2012 will be published later this year.

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