A recent report from the Alberta Land Institute highlights the economic benefits of expanding Alberta’s irrigation system and offers improved forecasting of agricultural and irrigation needs.
The report, entitled Systems modelling for sustainable land and water policy in Alberta’s irrigation sector, was prepared by Evan Davies, an associate professor in civil and environmental engineering at the University of Alberta.
The study, released in November, uses a new systems model — called CropSD — to assess sustainable land and water policy in Alberta’s irrigation sector. It is one of the most detailed model of its kind for river basins in Canada. CropSD simulates crop biomass and yield for six crop types; calculates irrigation demand for each crop based on on-farm irrigation technologies; gross irrigation water demands based on the conveyance network; and reservoir releases to satisfy irrigation demands.
Irrigation in Alberta generated nearly $3.2 billion to the province’s GDP in 2011, the report notes.
“The distribution of the benefits was 17 per cent for producers and 83 per cent for the province and the rest of Canada,” the report states. “These estimates suggest that the benefits of irrigation have almost tripled from 1980s estimates, while the share of those benefits accruing to producers has not significantly changed.”
The multi-year study found that expanding the irrigated area by 10 per cent (or 59,225 hectares) would produce a net-profit value of $78 million or $1,324 per hectare. However, such an expansion would be “economically unattractive for producers” unless government contributed 75 per cent of the costs for irrigation rehabilitation programs.
“The net benefits obtained from converting the dryland crops into irrigated crops are insufficient to cover the full investment costs required for irrigation expansion,” the report states.
This type of cutting-edge modelling systems are critical to policy-makers’ ability to manage Alberta’s water for municipal and agricultural activities, said Davies.
“With simulations running to 2040, our systems model serves as a decision-support tool at a high level of detail for municipalities, irrigation districts, government ministries, and other groups,” Davies said. “Specifically, for the City of Calgary, it generates medium- to long-term end-used-based water demand projections, and can be used to inform infrastructure and conservation planning.
“For irrigation districts, it simulates water efficiency, crop mix and infrastructure options, and projects crop production under various plausible future conditions. For provincial ministries, Alberta’s Watershed Planning and Advisory Councils and other groups, a fully realized model would provide detailed, long-term projections of watershed conditions; show possible consequences of water resources management options; and quantify trade-offs among water uses and their associated policies.”
There remains still work to do to couple the various models together between municipal, agricultural, and crop mix components, he added.
If stable water markets are the policy objective, then a water-sharing regime would be best regardless of the adequacy of the water supply, the study says. Such a flexible system will increase the welfare of licensed crop producers, livestock producers, the irrigation district and its members, it concludes.