In many semiarid regions, total water allocations exceed levels available for extraction. Despite growing demand for water from urban and environmental uses, the majority of these allocations are held by agricultural users. In order to meet new demand in the face of uncertain future supply, water must be reallocated from irrigation to urban and environmental uses; however, such reallocation faces stiff opposition from irrigators and non-irrigators alike. Although irrigators have disproportionate power over the reallocation process, the preferences of non-irrigators with greater electoral power and contributions to tax revenue are also important to policy makers. This study explores these issues based on extensive surveys of non-irrigators in Alberta, Canada. Values, beliefs, and attitudes are found to influence policy preferences differently. Policy makers and water managers should consider these psychological constructs when designing, marketing and implementing policies and mechanisms to reallocate water in accordance with the values of wider society.