Meeting the Water for Life challenge: Management scenarios to improve irrigation water use efficiency and reduce water demand in the Western Irrigation District, Alberta

Simulation of two alternative management scenarios—full rehabilitation and implementation of most efficient technologies, and water application restrictions—were investigated with the Irrigation Demand Model (IDM) as potential avenues to improve water use efficiency and reduce water demand in the Western Irrigation District (WID), Alberta. Results showed that the total district demand could decrease by up to 10% as a result of reduced on-farm and system losses. These improvements would not be sufficient to meet the goals of Water for Life. Simulation of water restriction applications showed that a limit of 6 inches/acre (502 mm/ha) would ensure adequate water supply for most crops, except alfalfa which would undergo yield reductions because of its high water requirements. The research demonstrated the strengths and limitations of existing models and investigated the use of CROPWAT for studying irrigated crops under reduced water supply in Alberta.