Mountain Water Supply Forecast Summary

Below-average runoff volumes are forecast for the March through September 2003 period in the Oldman, Milk and Bow River basins. Average runoff volumes are forecast for the North Saskatchewan River basin and above-average volumes are expected in the Red Deer River basin. Current forecasted volumes range from 74 to 113% of average for the March-September 2003 period (Table 1). Forecasted volumes are generally much higher than in 2001. Forecasted volumes are generally much higher than those recorded last year in the Red Deer and North Saskatchewan River basins, except for the Bighorn Reservoir, where forecasted volumes are 5% lower. Forecasted volumes are similar to last year's recorded volumes in the northern half of the Bow River basin, and much lower in the southern half of the Bow River basin as well as in the Milk and Oldman River basins.

Runoff volumes so far, from March through June 2003, have been below-average in the Oldman and Milk River basins, below-average to average in the Bow River basin, and average to above-average in the North Saskatchewan and Red Deer River basins.

Below-average runoff volumes are forecast for the July through September 2003 period in the Oldman, Milk, Bow, and North Saskatchewan River basins. Average to above-average runoff volumes are forecast for the Red Deer River basin.

These forecasts assume that precipitation over the remainder of the summer period will be normal. Mountain snowmelt is essentially complete for this year, especially in southern Alberta. Precipitation can have a major impact on the summer water supply forecast between now and the end of September. Streamflow volume forecasts will be updated monthly. Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.