Absence of historical temporal trends in monthly, seasonal, and annual streamflows for the Okanagan and Similkameen Rivers in south-central British Columbia, Canada

The rapidly growing population in the semi-arid climate of southcentral British Columbia, as well as the legal implications of transboundary water agreements such as the International Joint Commission (IJC), have led to substantial interest in the hydrology of this region and debate over the resulting environmental management policies [1-12]. In a previous work [13], we showed that despite substantial increases in population and agricultural activities over the past century the net water yield from the Canadian portion of the Okanagan Valley has not changed significantly during this time. In the current study, we examine potential historical temporal trends in monthly, seasonal, and annual mean, minimum, and maximum streamflows for the Okanagan and Similkameen Rivers (Figures 1 and 2), as well as any time trends for the date to peak of the spring freshet on both river systems.