North Saskatchewan River Basin - Water Supply Forecasts

Natural runoff volumes (for the March to September 2002 period) are forecast to be below-average for the Brazeau Reservoir and Lake Abraham and much-below-average for the North Saskatchewan River at Edmonton (Table 6a). Current forecasts in the basin range from 78 to 94 % of average. The North Saskatchewan River basin has a considerable drainage area in the plains area and with below-normal runoff forecast in these regions, the forecast at Edmonton is lower percentage-wise compared to the upstream locations (Brazeau Reservoir and Lake Abraham). Current snowpack at the higher elevations in the basin is average for this time of the year.

April forecasts were unchanged from last month's at Brazeau and Bighorn Reservoirs and increased 2 % at Edmonton due to above-normal snowfall in the plains area in between the two reservoirs and Edmonton. Current forecasted values for the March to September period for the North Saskatchewan River at Edmonton would rank 16th lowest in 84-years of record (1912-95). However, the April 1 forecasts are 11 to 17% higher than recorded values observed over the same time period last year.

The first month of the forecast period has been completed, with March 2002 recorded runoff volumes generally being the much-below-average, ranging from 28 to 117 % of average. Preliminary data indicates that the recorded March volume set new historical minimum values for the month at Brazeau Reservoir and Edmonton. The remaining volume forecast, which is the March to September 2002 forecast minus the recorded volume to date, is available in Table 6b.