Water Supply Outlook for Alberta

February 2003

Table 3 - Water Supply Forecast as of February 1, 2003 - Oldman River Basin (Natural Flows)

Volume Forecast for March 1 to September 30
Locations Volume in dam3 Volume as a % of Average Probable Range as a % of Average Reasonable Minimum as % of Average Forecast Ranking (lowest to highest) Recorded March-September 2002 Volume as a % of Average
St. Mary River 567,000* 75 56-116 46 15/84 155
Belly River 182,000 75 55-112 45 12/84 150
Waterton River 456,000 69 52-104 41 14/84 143
Oldman River near Brocket 693,000 63 41-102 36 13/84 147
Oldman River at Lethbridge 1,964,000 66 45-106 38 16/84 151

Note: Click on the site Location to see the Water Supply Forecast graphically

* - This value is the natural volume and includes the U.S. share
Average is calculated for the March 1 to September 30 period from 1912 to 1995

NOTE: There is: a 50% chance that the actual natural flow will fall within the probable range given; a 25% chance that the actual flow will be less than the lower bound of the probable range given; and a 10% chance that the actual natural flow will be less than the reasonable minimum. Actual day to day streamflow conditions may vary throughout the season as a result of the effects of streamflow diversion and reservoir storage.


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