Mountain Water Supply Forecast Summary

As of April 1, 2004, below-average to much-below-average natural runoff volumes are forecast for the Milk, Oldman, Bow and North Saskatchewan River basins for the March to September 2004 period, while below-average natural runoff volumes are forecast for the Red Deer River basin (Table 1). While snowpack conditions are generally below-average to much-below-average in the Oldman River basin, below-average in the Bow River basin, and below-average to average in the Red Deer and North Saskatchewan River basins, soil moisture conditions range from below-average to extremely dry. Forecasted March to September 2004 volumes are 7 to 22% lower than those recorded during the same period last year in the Milk, North Saskatchewan and Red Deer River basins, but generally 3 to 12% higher than last year in the Bow and Oldman River basins. Forecasted volumes are greater than the near-record lows recorded during the drought year of 2001. Changes from March 1 forecasts ranged from a 2% drop to a 7% rise except at Edmonton where a 6% drop occurred. Above-normal precipitation is needed to achieve average flow volumes in most basins this year.

The first month of the runoff season has finished, with preliminary data indicating March recorded volumes were below-average to much-below-average at about half of the forecast points and ranged from below-average to above-average at the other half.

These forecasts assume that precipitation over the summer 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 mid-summer. Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.