Northern Prairie Wildlife Research Center
Ducks Unlimited Canada, 350 Aquaduct Road, Box 818, Brooks, AB, T1R 1B7 Canada
The mixed grass prairie of southern Alberta is a major production area for North American waterfowl during years of favorable habitat conditions. However, during years of less favorable drought conditions, waterfowl production in southern Alberta is enhanced by irrigation-fed wetlands which have resulted from the development and management of water from an extensive agricultural irrigation system.
Historically, lands altered for cultivation have steadily increased in amount but grasslands remain a significant resource in southern Alberta where approximately 4 million ha remain in native vegetation. Cyclic drought conditions precipitated historic and ongoing development of irrigation systems. To date, over 400,000 ha of land are under irrigation development in southern Alberta, comprising approximately 65% of the irrigated land in Canada. Small grains are the main crops, with the remainder of the landbase remaining in native cover that is used for livestock grazing.
Geologic land forms include moraine, glacial meltwater channels, post-glacial lake beds, streams, and dissected bench lands. Moderate to high densities of potholes occur in moraine land forms. Many channel and coulee areas are utilized for irrigation conveyance and water storage. A total of 48,500 ha of wetlands has been developed in southern Alberta over the last 60 years. A total of 32,400 ha of wetlands has been created by complementing agricultural irrigation development. From the perspective of waterfowl production, these wetlands have essentially "drought-proofed" the prairie during recent years.
As a result of these irrigation developments, multi-basin projects have created wetland complexes that include up to 60 basins, which range in size and type from ephemeral wetlands less than 0.8 ha to permanent basins averaging ≥ 20 ha. Water levels are manipulated to manage vegetation to diversify habitats within wetlands. Wetlands created for irrigation projects are enhanced for production of waterfowl like Pintail (Anas acuta) because of the natural high availability of appropriate upland habitat. During wet years, wetlands created from irrigation development complement the availability of natural wetlands. This multiple-use approach has allowed programs to integrate agricultural land use with wetland developments for irrigation purposes to benefit waterfowl populations and agricultural producers.
The continued development of irrigated agriculture will provide more opportunities for Ducks Unlimited Canada, and Alberta Fish and Wildlife, under the auspices of the North American Waterfowl Management Plan (NAWMP), to create additional long-term water and upland management programs for the benefit of prairie nesting waterfowl. This increase in managed permanent wetlands, as well as a diversity of semipermanent habitat across the prairies is the first priority for NAWMP implementation in the prairie biome.