The first homesteaders to settle in what is now southern Alberta realized that irrigation would make the difference to their survival.
By the late 19th century, private groups were building canals and water delivery systems, and in 1910 the Canadian Pacific Railway embarked on two projects south of Calgary called the Eastern Block and the Western Block.
In 1935, the company said it could not afford to continue operating the system so a takeover was negotiated with local farmers.
The result was the Eastern and Western Irrigation Districts, which are run like municipalities and controlled by elected farmer boards.
Today, 13 irrigation districts bring water to 1.5 million acres in an area that stretches from south of Calgary to the U.S. border. It represents 65 percent of all Canada’s irrigation.
The Alberta government has granted the districts licences to withdraw river water totalling more than 3.8 million cubic decameters, making the irrigators the largest users of water in the province. The districts withdraw on average 67 percent of their allocation.
“We use the same amount of water today as we did in 1935 when we took over from the CPR,” said Earl Wilson, manager of the Eastern Irrigation District, which consists of 1.4 million acres and supplies water to farms, industry and communities.
Without irrigation, the dry, sunny south would not have its diversity of more than 40 crops, said Ron McMullin, manager of the Alberta Irrigation Projects Association. The potato, dry bean, sugar beet and vegetables industries would not exist, he added.
The amount of irrigated acreage has probably peaked with only minor expansion plans. No more water is available beyond what is already allocated because the provincial government halted new licences in the South Saskatchewan River basin two years ago.
“The water supply isn’t there to create another 50,000 acres of irrigation,” McMullin said.
“The water supply is finite and the districts realize that.”
The districts manage the network of canals, river diversions and delivery systems, but the farmers are expected to use water wisely.
In drought years, the districts reduce the amount of water they deliver to individual farms.
“If they have higher value crops like potatoes or sugar beets, they may irrigate their grains less and put their water on the beets and potatoes,” McMullin said.
He said farmers and districts have conserved approximately one percent of the water received per year since the 1960s because of better agriculture practices and new water delivery technology. They have reduced water losses to seepage, runoff, evaporation and wind drift.
The most water-efficient systems are pivot or lineal move systems with drop tubes and low-pressure spray nozzles designed to meet crop and soil requirements. Surface irrigation systems have been made more efficient by using gated pipe, surge valves and siphon tubes.
A government grant is available to help cover some of farmers’ costs to convert to a low-pressure pivot.
Further losses have been prevented with ongoing rehabilitation projects in which the province and districts share costs 75-25.
District money comes from farmers’ water use fees that range from zero in the Eastern Irrigation District to $21 per acre in the Ross Creek Irrigation District in Cypress County. Charges in the other districts’ are $9 to $16 per acre.
The Eastern Irrigation District has not charged fees since 2003 because of oil and gas revenues. It is unique among the districts because it is also a large landowner of 600,000 acres in southeastern Alberta.
The district covers 1.5 million acres, including dryland, on which it runs 10 community pastures and 100 private grazing lease agreements on native range.
Outside income helped its 1,000 farmer members install about 1,000 kilometres of pipeline to deliver water. The district has 2,000 km of canals in total.
“It is something that you have to continue to do. The canal system here is about 100 years old,” Wilson said.
Water conservation is critical in this area because it receives less than 10 inches of precipitation during the year. In 2000-01 an average of three inches fell in quarter inch increments.
“Those two years back to back were almost as bad as the ’30s,” he said.
“You plan on having those kind of years for (planning) your water consumption. Our plan is to be able to handle three 2001s back to back and not break the farmers.”
However, it is hard to predict how much water is available from year to year because they depend on runoff, snowpack and precipitation. Some years have almost no runoff but timely rain in May and June can set up the district for the summer.
“We look at the system as if we are in the first year of a drought every time we start. We can always change in July but you can’t reverse it,” he said.
“We start every season as if it was going to be a disaster and react accordingly.”