Mountain Water Supply Forecast Summary

As of July 1, 2004, natural runoff volumes to come, during the July-September period, are forecast to be generally below-average to average in the Bow and Red Deer River basins, below-average in the Milk River basin, and below to much-below-average in the Oldman and North Saskatchewan River basins.

The first four months of the runoff season have finished, with preliminary data as of July 1 indicating March-June natural runoff volumes ranged from below to much-below-average at most forecast points, except below average to average at the Bighorn Reservoir and average at the Cascade Reservoir.

As of July 1, 2004, Alberta Environment natural runoff volume forecasts for the March through September 2004 period range from below to much-below-average in the Milk, Oldman, Bow, Red Deer and North Saskatchewan River basins, with the exception of the Cascade Reservoir, where near average inflow volumes are forecast (Table 1).

Forecasted March to September 2004 volumes are 5 to 15% lower than those recorded during the same period last year in the North Saskatchewan River basin, 21 to 31% lower in the Milk and Red Deer River basins, 0 to 9% higher in the Bow River basin except the Highwood River which is 11% lower, and 4 to 13% higher in the Oldman River basin except at Brocket, which is 4% lower. Changes from June 1 forecasts generally ranged from a 5% drop at Red Deer and in the Milk River to a 13% rise at Belly River.

These forecasts assume that precipitation for the remainder of the forecast period will be normal. Precipitation will have a major impact on the summer water supply forecast between now and the end of September. Streamflow volume forecasts will be updated monthly until August. Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.