Bow River Basin - Water Supply Forecasts

As of July 1, 2004, March to September 2004 natural runoff volumes are forecast to be much-below-average at Banff, below to much below average in the Highwood River, below average in the Kananaskis and Elbow Rivers and at Calgary and the Spray Reservoir, and near average at the Cascade Reservoir (Table 4a). Current runoff volume forecasts range from 61 to 93% of average. Since June 1, changes in the forecasts range from 9% lower in the Highwood River to 12% higher at the Cascade Reservoir. Current March to September 2004 volume forecasts are 0-9% higher than runoff volumes recorded during the same period last year, except for the Highwood River, which is forecast to receive 11% less volume than last year. Current forecasted volumes for the March to September 2004 period for the Bow River at Calgary would rank 24th lowest in 91 years of record (1912-2001).

The first four months of the forecast period have been completed, with March-June 2004 recorded runoff volumes ranging from 54 to 94% of average. The Highwood River and Banff recorded much-below-average runoff so far, Kananaskis recorded below to much below average runoff, the Cascade Reservoir recorded normal runoff, while Calgary, the Elbow River and Spray Reservoir recorded below average runoff. Recorded volume data is preliminary, and is subject to change. Current volumes represent approximately half of the volumes forecasted. The remaining volume forecast, which is the March to September 2004 forecast minus the recorded volume to date, is available in Table 4b. Below-average runoff is forecasted for the July through September 2004 period, except at the Cascade Reservoir where average runoff is forecasted, and the Highwood River, where below average to average runoff is forecasted.