Oldman River Basin - Water Supply Forecasts

As of March 1, 2004, below-average to much-below-average natural runoff volumes are forecast for the March to September 2004 period in the Oldman River basin (Table 3). Current forecasted values for the March to September 2004 period for the Oldman River at Lethbridge would rank 20th lowest in 91-years of record (1912-2001). Current runoff volume forecasts range from 71 to 78% of average, 5 to 7% less than last month's forecasted volumes. The March to September 2004 forecast volumes are 4 to 14% higher than those recorded during the same period last year, in all but the Belly River basin, where volumes are forecast to be 6% lower than last year's. The upper Oldman River basin has better snowpack and soil moisture conditions than the southern tributaries (Waterton, St.Mary, and Belly River basins), and as a result better runoff volumes are forecast, as evident in the forecasts' historical rankings.