Oldman River Basin - Water Supply Forecasts

Below-average natural runoff volumes are forecast for the March to September 2003 period in the Oldman River basin, ranging from 69 to 87% of average (Table 3a). The March to September 2003 forecast volumes are 9 to 33% higher than those recorded in the same period in 2001 and are just over half the volumes recorded last year. Current forecasted values for the March to September 2003 period for the Oldman River at Lethbridge would rank 20th lowest in 85 years of record (1912-95).

The first four months of the forecast period have been completed, with snowmelt essentially finished for the year. March-June 2003 recorded runoff volumes ranged from 71 to 89% of average. The remaining volume forecast, which is the March to September 2003 forecast minus the recorded volume to date, is available in Table 3b.