Irrigating the Prairies

Southern Alberta’s early pioneers found almost all the ingredients for farm life — abundant sunshine, warm temperatures and a long growing season.

What was missing was rain. Making matters worse were the chinook winds whipping moisture out of the soil. The driest pocket — the southeast corner of the province — receives 380 mm less than the water needed each year to grow the region’s crops.

'No drought here!'

Selling semi-arid land to farmers was made tougher by a drought in the 1880s.

The first large-scale irrigation success in the province was a 184-kilometre canal dug by the Canadian North-West Irrigation Company, which diverted water from the St. Mary River. Built by Mormon settlers with know-how from their former home of Utah, the canal was completed in 1900, opening up thousands of hectares of land for farming in the Lethbridge area.

Lethbridge town council bought promotional ads extolling the new southeast Alberta. “No drought here!” and “Every man his own rainmaker” were two of the slogans.

Irrigation a century later

Today, the St. Mary River Irrigation District draws water from the Belly, Waterton and St. Mary rivers using a 1,719-kilometre distribution system.

That’s only one part of a larger system of dams, dikes, canals and pipelines that diverts river and stream water to 505,000 hectares of Alberta land.

• Irrigation accounts for 71 per cent of the province’s use of surface water.
• Licence holders in the province can potentially withdraw more than 3.8 million cubic decameters of water (3.8 trillion litres).
• About 20 per cent of the province’s agriculture products are irrigated.
• Alberta Agriculture estimates that irrigation adds 35,000 jobs and more than $940 million into the province’s economy.

Concerns today

With southern Albertas population growing and water supplies fluctuating in recent years, some are raising questions about how much of the resource should be going toward irrigating semi-arid land.

Among those voicing concern is Jim Byrne, the former director of the University of Lethbridges Water Resources Institute, who has called on farmers to use water more efficiently. As water supplies are stretched thin over the next 20 to 50 years, Alberta will inevitably need to reduce its dependence on irrigation, he said.

Adding to tensions, Alberta operates under the “first in time, first in right” policy, which dates back to 1894.

That gives those with the oldest water licences priority to water, so during a drought, city or town dwellers could be asked to ration water while a farmer with a long-held licence is irrigating his crops.

Early this year, the province decided it would no longer issue new water-use licences for three southern Alberta rivers — the Bow, Oldman and South Saskatchewan.

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